{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,8]],"date-time":"2026-09-08T17:08:30Z","timestamp":1788887310897,"version":"build-2803163510"},"reference-count":131,"publisher":"Springer Science and Business Media LLC","issue":"7","license":[{"start":{"date-parts":[[2026,9,8]],"date-time":"2026-09-08T00:00:00Z","timestamp":1788825600000},"content-version":"tdm","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0"},{"start":{"date-parts":[[2026,9,8]],"date-time":"2026-09-08T00:00:00Z","timestamp":1788825600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0"}],"content-domain":{"domain":["link.springer.com"],"crossmark-restriction":false},"short-container-title":["AAPS PharmSciTech"],"abstract":"<jats:title>Abstract<\/jats:title>\n                  <jats:p>\n                    Gastro-resistant oral dosage forms remain essential for protecting acid-labile active pharmaceutical ingredients, reducing gastric irritation, and enabling site-specific intestinal or colonic drug delivery. Although conventional enteric coatings are well established, their\n                    <jats:italic>in vivo<\/jats:italic>\n                    performance remains affected by gastric pH variability, food intake, alcohol exposure, gastric residence time, coating integrity, and interindividual differences in gastrointestinal transit. Advanced platforms, including ready-to-fill enteric capsules, hot-melt technologies, three-dimensional printing, electrospinning, micro- and nanocarriers, and pH-responsive hydrogels, have been proposed to overcome these limitations, but many remain at an experimental or early translational stage. This narrative review critically evaluates gastro-resistant oral formulations from technological, physiological, and regulatory perspectives. It compares established and emerging technologies with respect to release mechanisms, material requirements, processing constraints, acid-resistance performance, translational maturity, scalability, regulatory acceptability, and commercial feasibility. Recent advances, including rapid-release double-coating concepts and dual pH- and microbiota-triggered colonic delivery systems, are also discussed. Overall, the field is moving from simple gastric protection toward more predictive and functionally complex oral drug delivery platforms. Future progress will depend on biorelevant dissolution testing, stronger\n                    <jats:italic>in vitro<\/jats:italic>\n                    \u2013\n                    <jats:italic>in vivo<\/jats:italic>\n                    correlations, quality-by-design approaches, process analytical technologies, greener manufacturing, and regulatory pathways capable of accommodating innovative materials and personalized oral therapeutics.\n                  <\/jats:p>","DOI":"10.1208\/s12249-026-03529-w","type":"journal-article","created":{"date-parts":[[2026,9,8]],"date-time":"2026-09-08T16:44:47Z","timestamp":1788885887000},"update-policy":"https:\/\/doi.org\/10.1007\/springer_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Oral Gastro-resistant Formulations \u2013 State of the Art, Advances and Prospects: A Review"],"prefix":"10.1208","volume":"27","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-0983-1922","authenticated-orcid":false,"given":"Maja","family":"Frankiewicz","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8195-9883","authenticated-orcid":false,"given":"Bartosz","family":"Maciejewski","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0866-0452","authenticated-orcid":false,"given":"Malgorzata","family":"Sznitowska","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"297","published-online":{"date-parts":[[2026,9,8]]},"reference":[{"key":"3529_CR1","volume-title":"Pharmaceutical coating technology","year":"1995","unstructured":"Cole G, Hogan J, Aulton M, editors. Pharmaceutical coating technology. London: Taylor & Francis; 1995."},{"issue":"3","key":"3529_CR2","doi-asserted-by":"publisher","first-page":"235","DOI":"10.1016\/S0168-3659(99)00204-7","volume":"63","author":"BN Singh","year":"2000","unstructured":"Singh BN, Kim KH. Floating drug delivery systems: an approach to oral controlled drug delivery via gastric retention. J Control Release. 2000;63(3):235\u201359. https:\/\/doi.org\/10.1016\/S0168-3659(99)00204-7.","journal-title":"J Control Release."},{"issue":"6","key":"3529_CR3","doi-asserted-by":"publisher","first-page":"606","DOI":"10.5281\/zenodo.11550881","volume":"2","author":"S Singh","year":"2024","unstructured":"Singh S, Singh K, Yogita RH. A review on gastro retentive drug delivery system: novel approach with the future perspectives. Int J Pharm Sci. 2024;2(6):606\u201321. https:\/\/doi.org\/10.5281\/zenodo.11550881.","journal-title":"Int J Pharm Sci"},{"issue":"2","key":"3529_CR4","doi-asserted-by":"publisher","first-page":"281","DOI":"10.1016\/S0016-5085(83)80124-3","volume":"84","author":"RA Hinder","year":"1983","unstructured":"Hinder RA, San-Garde BA. Individual and combined roles of the pylorus and the antrum in the canine gastric emptying of a liquid and a digestible solid. Gastroenterology. 1983;84(2):281\u20136. https:\/\/doi.org\/10.1016\/S0016-5085(83)80124-3.","journal-title":"Gastroenterology"},{"key":"3529_CR5","unstructured":"Sznitowska M, Biofarmacja KR. Warszawa: PZWL; 2014. p. 88, 115-116."},{"issue":"2","key":"3529_CR6","doi-asserted-by":"publisher","first-page":"446","DOI":"10.1016\/j.ijpharm.2013.04.034","volume":"457","author":"FJO Varum","year":"2013","unstructured":"Varum FJO, Hatton GB, Basit AW. Food, physiology and drug delivery. Int J Pharm. 2013;457(2):446\u201360. https:\/\/doi.org\/10.1016\/j.ijpharm.2013.04.034.","journal-title":"Int J Pharm"},{"key":"3529_CR7","doi-asserted-by":"publisher","first-page":"5","DOI":"10.1186\/s41120-017-0014-9","volume":"3","author":"S D'Souza","year":"2017","unstructured":"D\u2019Souza S, Mayock S, Salt A. A review of in vivo and in vitro aspects of alcohol-induced dose dumping. AAPS Open. 2017;3:5. https:\/\/doi.org\/10.1186\/s41120-017-0014-9.","journal-title":"AAPS Open."},{"issue":"2","key":"3529_CR8","doi-asserted-by":"publisher","DOI":"10.3390\/pharmaceutics17020161","volume":"17","author":"S Ramesh","year":"2025","unstructured":"Ramesh S, Zvon\u00ed\u010dek V, P\u011b\u010dek D, Pi\u0161lov\u00e1 M, Ber\u00e1nek J, Hofmann J, et al. Acid-neutralizing omeprazole formulation for rapid release and absorption. Pharmaceutics. 2025;17(2):161. https:\/\/doi.org\/10.3390\/pharmaceutics17020161.","journal-title":"Pharmaceutics"},{"key":"3529_CR9","unstructured":"European Directorate for the Quality of Medicines & HealthCare. European Pharmacopoeia 11th Edition Online. Strasbourg: EDQM [cited 2026 Jun 13]. Available from: https:\/\/pheur-online.edqm.eu\/content\/"},{"key":"3529_CR10","unstructured":"European Directorate for the Quality of Medicines & HealthCare. Standard Terms. Strasbourg: EDQM [cited 2026 Jun 13]. Available from: https:\/\/standardterms.edqm.eu\/"},{"key":"3529_CR11","volume-title":"Physicochemical principles of pharmacy: in manufacture, formulation and clinical use","author":"AT Florence","year":"2015","unstructured":"Florence AT, Attwood D. Physicochemical principles of pharmacy: in manufacture, formulation and clinical use. 6th ed. London: Pharmaceutical Press; 2015.","edition":"6th ed"},{"key":"3529_CR12","doi-asserted-by":"publisher","first-page":"113915","DOI":"10.1016\/j.addr.2021.113915","volume":"177","author":"K Stamatopoulos","year":"2021","unstructured":"Stamatopoulos K, O\u2019Farrell C, Simmons M, Batchelor H. In vivo models to evaluate ingestible devices: present status and current trends. Adv Drug Deliv Rev. 2021;177:113915. https:\/\/doi.org\/10.1016\/j.addr.2021.113915.","journal-title":"Adv Drug Deliv Rev."},{"key":"3529_CR13","doi-asserted-by":"publisher","unstructured":"Yang Y, Zhao Y, Yu A, Sun D, Yu LX. Oral drug absorption: evaluation and prediction. In: Qiu Y, Chen Y, Zhang GGZ, Yu L, Mantri RV, editors. Developing solid oral dosage forms: pharmaceutical theory and practice. 2nd ed. London: Academic Press; 2017. p. 331\u201354. https:\/\/doi.org\/10.1016\/B978-0-12-802447-8.00012-1.","DOI":"10.1016\/B978-0-12-802447-8.00012-1"},{"issue":"9","key":"3529_CR14","first-page":"124","volume":"8","author":"WG Chambliss","year":"1983","unstructured":"Chambliss WG. The forgotten dosage form: enteric coated tablets. Pharm Technol. 1983;8(9):124\u201340.","journal-title":"Pharm Technol."},{"issue":"1","key":"3529_CR15","doi-asserted-by":"publisher","first-page":"1","DOI":"10.1016\/j.ejpb.2008.12.013","volume":"72","author":"A Makhlof","year":"2009","unstructured":"Makhlof A, Tozuka Y, Takeuchi H. PH-sensitive nanospheres for colon-specific drug delivery in experimentally induced colitis rat model. Eur J Pharm Biopharm. 2009;72(1):1\u20138. https:\/\/doi.org\/10.1016\/j.ejpb.2008.12.013.","journal-title":"Eur J Pharm Biopharm"},{"key":"3529_CR16","doi-asserted-by":"publisher","first-page":"39","DOI":"10.1016\/j.addr.2016.03.001","volume":"108","author":"J Norman","year":"2017","unstructured":"Norman J, Madurawe RD, Moore CMV, Khan MA, Khairuzzaman A. A new chapter in pharmaceutical manufacturing: 3D-printed drug products. Adv Drug Deliv Rev. 2017;108:39\u201350. https:\/\/doi.org\/10.1016\/j.addr.2016.03.001.","journal-title":"Adv Drug Deliv Rev."},{"issue":"2","key":"3529_CR17","doi-asserted-by":"publisher","first-page":"217","DOI":"10.1517\/17425247.3.2.217","volume":"3","author":"A Streubel","year":"2006","unstructured":"Streubel A, Siepmann J, Bodmeier R. Gastroretentive drug delivery systems. Expert Opin Drug Deliv. 2006;3(2):217\u201333. https:\/\/doi.org\/10.1517\/17425247.3.2.217.","journal-title":"Expert Opin Drug Deliv."},{"key":"3529_CR18","unstructured":"European Medicines Agency. Guideline on quality of oral modified release products. Amsterdam: European Medicines Agency; 2014 [cited 2026 Jun 13]. Available from: https:\/\/www.ema.europa.eu\/en\/quality-oral-modified-release-products-scientific-guidelines"},{"issue":"1","key":"3529_CR19","doi-asserted-by":"publisher","first-page":"15","DOI":"10.1089\/act.2000.6.15","volume":"6","author":"S Holt","year":"2000","unstructured":"Holt S. New formulations of dietary supplements can deliver new benefits. Altern Complement Ther. 2000;6(1):15\u20139. https:\/\/doi.org\/10.1089\/act.2000.6.15.","journal-title":"Altern Complement Ther."},{"issue":"1\u20132","key":"3529_CR20","doi-asserted-by":"publisher","first-page":"35","DOI":"10.1016\/j.ijpharm.2004.12.024","volume":"293","author":"S Missaghi","year":"2005","unstructured":"Missaghi S, Fassihi R. Release characterization of dimenhydrinate from an eroding and swelling matrix: selection of appropriate dissolution apparatus. Int J Pharm. 2005;293(1\u20132):35\u201342. https:\/\/doi.org\/10.1016\/j.ijpharm.2004.12.024.","journal-title":"Int J Pharm."},{"issue":"8","key":"3529_CR21","doi-asserted-by":"publisher","first-page":"945","DOI":"10.3390\/children11080945","volume":"11","author":"K Rouaz-El-Hajoui","year":"2024","unstructured":"Rouaz-El-Hajoui K, Garc\u00eda-Montoya E, Su\u00f1\u00e9-Pou M, Su\u00f1\u00e9-Negre JM, P\u00e9rez-Lozano P. Application of galenic strategies for developing gastro-resistant omeprazole formulation for pediatrics. Children (Basel). 2024;11(8):945. https:\/\/doi.org\/10.3390\/children11080945.","journal-title":"Children (Basel)."},{"key":"3529_CR22","volume-title":"United States pharmacopeia 43-national formulary 38","author":"United States Pharmacopeial Convention","year":"2020","unstructured":"United States Pharmacopeial Convention. United States pharmacopeia 43-national formulary 38. Rockville: United States Pharmacopeial Convention; 2020."},{"key":"3529_CR23","unstructured":"European Commission, Directorate-General for Health and Food Safety. EudraLex, volume 4: EU guidelines to good manufacturing practice medicinal products for human and veterinary use. Brussels: European Commission; 2022 [cited 2026 Jun 13]. Available from: https:\/\/health.ec.europa.eu\/latest-updates\/eudralex-volume-4-eu-guidelines-good-manufacturing-practice-medicinal-products-human-and-veterinary-2022-02-21_en"},{"key":"3529_CR24","unstructured":"U.S. Food and Drug Administration. Q7A good manufacturing practice guidance for active pharmaceutical ingredients. Silver Spring (MD): U.S. Food and Drug Administration; 2001 [cited 2026 Jun 13]. Available from: https:\/\/www.fda.gov\/regulatory-information\/search-fda-guidance-documents\/q7a-good-manufacturing-practice-guidance-active-pharmaceutical-ingredients"},{"key":"3529_CR25","unstructured":"International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use. ICH Q8(R2) pharmaceutical development. Amsterdam: European Medicines Agency; 2009 [cited 2026 Jun 13]. Available from: https:\/\/www.ema.europa.eu\/en\/ich-q8-r2-pharmaceutical-development-scientific-guideline"},{"issue":"8","key":"3529_CR26","doi-asserted-by":"publisher","first-page":"2488","DOI":"10.1016\/j.apsb.2021.03.015","volume":"11","author":"M Cui","year":"2021","unstructured":"Cui M, Pan H, Su Y, Fang D, Qiao S, Ding P, et al. Opportunities and challenges of three-dimensional printing technology in pharmaceutical formulation development. Acta Pharm Sin B. 2021;11(8):2488\u2013504. https:\/\/doi.org\/10.1016\/j.apsb.2021.03.015.","journal-title":"Acta Pharm Sin B"},{"key":"3529_CR27","unstructured":"International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use. ICH guideline Q13 on continuous manufacturing of drug substances and drug products. Amsterdam: European Medicines Agency; 2023 [cited 2026 Jun 13]. Available from: https:\/\/www.ema.europa.eu\/en\/ich-guideline-q13-continuous-manufacturing-drug-substances-and-drug-products-scientific-guideline"},{"key":"3529_CR28","unstructured":"U.S. Food and Drug Administration. Guidance for industry: PAT \u2014 a framework for innovative pharmaceutical development, manufacturing, and quality assurance [Internet]. Silver Spring (MD): U.S. Food and Drug Administration; 2004 [cited 2026 Jun 13]. Available from: https:\/\/www.fda.gov\/regulatory-information\/search-fda-guidance-documents\/pat-framework-innovative-pharmaceutical-development-manufacturing-and-quality-assurance"},{"key":"3529_CR29","unstructured":"International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use. ICH Q14 analytical procedure development. Amsterdam: European Medicines Agency; 2024 [cited 2026 Jun 13]. Available from: https:\/\/www.ema.europa.eu\/en\/ich-q14-analytical-procedure-development-scientific-guideline"},{"issue":"8","key":"3529_CR30","doi-asserted-by":"publisher","first-page":"e8897","DOI":"10.2903\/j.efsa.2024.8897","volume":"22","author":"M Younes","year":"2024","unstructured":"Younes M, Aquilina G, Castle L, Degen G, Engel K, Fowler P, et al. Re-evaluation of shellac (E 904) as a food additive and a new application on the extension of use of shellac (E 904) in dietary foods for special medical purposes. EFSA J. 2024;22(8):e8897. https:\/\/doi.org\/10.2903\/j.efsa.2024.8897.","journal-title":"EFSA J."},{"key":"3529_CR31","unstructured":"European Parliament and Council of the European Union. Regulation (EC) No 1333\/2008 of 16 December 2008 on food additives. Brussels: European Union; 2008 [cited 2026 Jun 13]. Available from: https:\/\/eur-lex.europa.eu\/eli\/reg\/2008\/1333\/2026-02-18\/eng"},{"key":"3529_CR32","unstructured":"U.S. Food and Drug Administration. GRN No. 960: hypromellose acetate succinate. Silver Spring (MD): U.S. Food and Drug Administration; 2021 [cited 2026 Jun 13]. Available from: https:\/\/hfpappexternal.fda.gov\/scripts\/fdcc\/index.cfm?id=960&set=GRASNotices"},{"key":"3529_CR33","unstructured":"U.S. Food and Drug Administration. Shellac, purified. Silver Spring (MD): U.S. Food and Drug Administration; [cited 2026 Jun 13]. Available from: https:\/\/hfpappexternal.fda.gov\/scripts\/fdcc\/index.cfm?id=SHELLACPURIFIED&set=FoodSubstances"},{"key":"3529_CR34","volume-title":"Polymers for controlled drug delivery","year":"1990","unstructured":"Tarcha PJ, editor. Polymers for controlled drug delivery. Boca Raton: CRC Press; 1990."},{"key":"3529_CR35","doi-asserted-by":"publisher","first-page":"4613","DOI":"10.2147\/DDDT.S277439","volume":"14","author":"AN Zaid","year":"2020","unstructured":"Zaid AN. A comprehensive review on pharmaceutical film coating: past, present, and future. Drug Des Devel Ther. 2020;14:4613\u201323. https:\/\/doi.org\/10.2147\/DDDT.S277439.","journal-title":"Drug Des Devel Ther"},{"issue":"3","key":"3529_CR36","first-page":"47","volume":"10","author":"BA Shah","year":"2018","unstructured":"Shah BA, Patel AS, Patel BJ, Patel DJ, Qu A. Mini-tablet drug delivery system for pediatric dosage form: a review of manufacturing perspectives. Int J Drug Dev Res. 2018;10(3):47\u201352.","journal-title":"Int J Drug Dev Res"},{"issue":"4","key":"3529_CR37","doi-asserted-by":"publisher","first-page":"236","DOI":"10.25004\/IJPSDR.2010.020403","volume":"2","author":"S Srivastava","year":"2010","unstructured":"Srivastava S, Mishra G. Fluid bed technology: overview and parameters for process selection. Int J Pharm Sci Drug Res. 2010;2(4):236\u201346. https:\/\/doi.org\/10.25004\/IJPSDR.2010.020403.","journal-title":"Int J Pharm Sci Drug Res."},{"issue":"1","key":"3529_CR38","doi-asserted-by":"publisher","first-page":"31","DOI":"10.1080\/03639045.2019.1698596","volume":"46","author":"M Szczepanska","year":"2019","unstructured":"Szczepanska M, Paduszynski P, Kotlowska H, Sznitowska M. Optimization of the coating process of minitablets in two different lab-scale fluid bed systems. Drug Dev Ind Pharm. 2019;46(1):31\u201341. https:\/\/doi.org\/10.1080\/03639045.2019.1698596.","journal-title":"Drug Dev Ind Pharm."},{"issue":"14","key":"3529_CR39","doi-asserted-by":"publisher","first-page":"1611","DOI":"10.3109\/03639049509069251","volume":"21","author":"AM Twitchell","year":"1995","unstructured":"Twitchell AM, Hogan JE, Aulton ME. Assessment of the thickness variation and surface roughness of aqueous film coated tablets using a light-section microscope. Drug Dev Ind Pharm. 1995;21(14):1611\u20139. https:\/\/doi.org\/10.3109\/03639049509069251.","journal-title":"Drug Dev Ind Pharm."},{"issue":"1","key":"3529_CR40","doi-asserted-by":"publisher","first-page":"69","DOI":"10.1590\/S1984-82502012000100008","volume":"48","author":"AT Patil","year":"2012","unstructured":"Patil AT, Khobragade DS, Chafle SA, Ujjainkar AP, Umathe SN, Lakhotia CL. Development and evaluation of a hot-melt coating technique for enteric coating. Braz J Pharm Sci. 2012;48(1):69\u201377. https:\/\/doi.org\/10.1590\/S1984-82502012000100008.","journal-title":"Braz J Pharm Sci."},{"key":"3529_CR41","doi-asserted-by":"publisher","first-page":"185","DOI":"10.1016\/j.powtec.2014.09.016","volume":"269","author":"R Albanez","year":"2015","unstructured":"Albanez R, Nitz M, Taranto OP. Influence of the type of enteric coating suspension, coating layer and process conditions on dissolution profile and stability of coated pellets of diclofenac sodium. Powder Technol. 2015;269:185\u201392. https:\/\/doi.org\/10.1016\/j.powtec.2014.09.016.","journal-title":"Powder Technol"},{"key":"3529_CR42","volume-title":"EUDRAGIT application guidelines","author":"Evonik Industries AG","year":"2012","unstructured":"Evonik Industries AG. EUDRAGIT application guidelines. 12th ed. Essen: Evonik Industries AG; 2012.","edition":"12th ed"},{"issue":"5","key":"3529_CR43","doi-asserted-by":"publisher","first-page":"882","DOI":"10.1023\/B:PHAM.0000026443.71935.cb","volume":"21","author":"F Lecomte","year":"2004","unstructured":"Lecomte F, Siepmann J, Walther M, MacRae RJ, Bodmeier R. Polymer blends used for the coating of multiparticulates: comparison of aqueous and organic coating techniques. Pharm Res. 2004;21(5):882\u201390. https:\/\/doi.org\/10.1023\/B:PHAM.0000026443.71935.cb.","journal-title":"Pharm Res."},{"key":"3529_CR44","unstructured":"International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use. ICH Q3C(R9): Guideline on impurities: guideline for residual solvents. Amsterdam: European Medicines Agency; 2024 [cited 2026 Jun 13]. Available from: https:\/\/www.ema.europa.eu\/en\/ich-q3c-r9-residual-solvents-scientific-guideline"},{"key":"3529_CR45","volume-title":"TLVs and BEIs: threshold limit values for chemical substances and physical agents","author":"ACGIH","year":"2023","unstructured":"ACGIH. TLVs and BEIs: threshold limit values for chemical substances and physical agents. Cincinnati: American Conference of Governmental Industrial Hygienists; 2023."},{"key":"3529_CR46","first-page":"309","volume":"L96","author":"European Parliament and Council of the European Union","year":"2014","unstructured":"European Parliament and Council of the European Union. Directive 2014\/34\/EU on equipment and protective systems intended for use in potentially explosive atmospheres. Off J Eur Union. 2014;L96:309\u201356.","journal-title":"Off J Eur Union."},{"key":"3529_CR47","unstructured":"European Medicines Agency. Reflection paper on the use of organic solvents in the manufacture of pharmaceutical products. London: European Medicines Agency; 2010 [cited 2026 Jun 13]. Available from: https:\/\/www.ema.europa.eu\/en\/documents\/scientific-guideline\/reflection-paper-use-recoveredrecycled-solvents-manufacture-herbal-preparations-use-herbal-medicinal-products-traditional-herbal-medicinal-products_en.pdf"},{"key":"3529_CR48","doi-asserted-by":"publisher","first-page":"123","DOI":"10.1016\/j.jclepro.2013.01.004","volume":"44","author":"Z Boltic","year":"2013","unstructured":"Boltic Z, Ruzic N, Jovanovic M, Savic M, Jovanovic J, Petrovic S. Cleaner production aspects of tablet coating process in pharmaceutical industry: problem of VOCs emission. J Clean Prod. 2013;44:123\u201332. https:\/\/doi.org\/10.1016\/j.jclepro.2013.01.004.","journal-title":"J Clean Prod"},{"issue":"1","key":"3529_CR49","doi-asserted-by":"publisher","first-page":"5","DOI":"10.1111\/j.2042-7158.1982.tb04667.x","volume":"34","author":"SC Porter","year":"1982","unstructured":"Porter SC, Ridgway K. The permeability of enteric coatings and the dissolution rates of coated tablets. J Pharm Pharmacol. 1982;34(1):5\u20138. https:\/\/doi.org\/10.1111\/j.2042-7158.1982.tb04667.x.","journal-title":"J Pharm Pharmacol"},{"issue":"3","key":"3529_CR50","first-page":"141","volume":"6","author":"S Islam","year":"2016","unstructured":"Islam S, Khatun F, Mondal I, Haque M, Mahmud A. A review on biodegradable polymers for enteric coating material. Int J Pharm Pharm Res. 2016;6(3):141\u201359.","journal-title":"Int J Pharm Pharm Res."},{"issue":"3","key":"3529_CR51","doi-asserted-by":"publisher","first-page":"209","DOI":"10.2174\/187221108786241633","volume":"2","author":"S Behzadi","year":"2008","unstructured":"Behzadi S, Toegel S, Viernstein H. Innovations in coating technology. Recent Pat Drug Deliv Formul. 2008;2(3):209\u201330. https:\/\/doi.org\/10.2174\/187221108786241633.","journal-title":"Recent Pat Drug Deliv Formul."},{"issue":"2","key":"3529_CR52","doi-asserted-by":"publisher","first-page":"119","DOI":"10.1016\/j.jconrel.2008.09.083","volume":"133","author":"F Liu","year":"2009","unstructured":"Liu F, Lizio R, Meier C, Petereit HU, Blakey P, Basit AW. A novel concept in enteric coating: a double-coating system providing rapid drug release in the proximal small intestine. J Control Release. 2009;133(2):119\u201324. https:\/\/doi.org\/10.1016\/j.jconrel.2008.09.083.","journal-title":"J Control Release."},{"issue":"2","key":"3529_CR53","doi-asserted-by":"publisher","first-page":"242","DOI":"10.1016\/j.jconrel.2010.07.105","volume":"147","author":"F Liu","year":"2010","unstructured":"Liu F, Basit AW. A paradigm shift in enteric coating: achieving rapid release in the proximal small intestine of man. J Control Release. 2010;147(2):242\u20135. https:\/\/doi.org\/10.1016\/j.jconrel.2010.07.105.","journal-title":"J Control Release."},{"issue":"2","key":"3529_CR54","doi-asserted-by":"publisher","first-page":"311","DOI":"10.1016\/j.ejpb.2009.11.008","volume":"74","author":"F Liu","year":"2010","unstructured":"Liu F, Moreno P, Basit AW. A novel double-coating approach for improved pH-triggered delivery to the ileo-colonic region of the gastrointestinal tract. Eur J Pharm Biopharm. 2010;74(2):311\u20135. https:\/\/doi.org\/10.1016\/j.ejpb.2009.11.008.","journal-title":"Eur J Pharm Biopharm."},{"issue":"3","key":"3529_CR55","doi-asserted-by":"publisher","first-page":"573","DOI":"10.1016\/j.ejpb.2013.01.002","volume":"84","author":"FJO Varum","year":"2013","unstructured":"Varum FJO, Hatton GB, Freire AC, Basit AW. A novel coating concept for ileo-colonic drug targeting: proof of concept in humans using scintigraphy. Eur J Pharm Biopharm. 2013;84(3):573\u20137. https:\/\/doi.org\/10.1016\/j.ejpb.2013.01.002.","journal-title":"Eur J Pharm Biopharm"},{"key":"3529_CR56","doi-asserted-by":"publisher","first-page":"119379","DOI":"10.1016\/j.ijpharm.2020.119379","volume":"583","author":"F Varum","year":"2020","unstructured":"Varum F, Freire AC, Fadda HM, Bravo R, Basit AW. A dual pH and microbiota-triggered coating (Phloral\u2122) for fail-safe colonic drug release. Int J Pharm. 2020;583:119379. https:\/\/doi.org\/10.1016\/j.ijpharm.2020.119379.","journal-title":"Int J Pharm"},{"key":"3529_CR57","doi-asserted-by":"publisher","DOI":"10.1016\/j.ijpharm.2020.119372","volume":"583","author":"F Varum","year":"2020","unstructured":"Varum F, Freire AC, Bravo R, Basit AW. Opticore\u2122, an innovative and accurate colonic targeting technology. Int J Pharm. 2020;583:119372. https:\/\/doi.org\/10.1016\/j.ijpharm.2020.119372.","journal-title":"Int J Pharm"},{"key":"3529_CR58","unstructured":"Evonik Operations GmbH. DuoCoat\u00ae: an innovative EUDRAGIT\u00ae based system. Essen: Evonik Operations GmbH; 2020 [cited 2026 Jun 13]. Available from: https:\/\/www.evonik.com\/content\/dam\/evonik\/documents\/evonik-flyer-duocoat.pdf"},{"key":"3529_CR59","unstructured":"Swedish Medical Products Agency. Asacol 1600 mg modified-release tablets: summary of product characteristics. Uppsala: Swedish Medical Products Agency; [cited 2026 Jun 13]. Available from: https:\/\/docetp.mpa.se\/LMF\/Asacol%20Modified-release%20tablet%20ENG%20SmPC_09001bee807a3636.pdf"},{"key":"3529_CR60","unstructured":"Jones BE. Capsules, hard. In: Swarbrick J, editor. Encyclopedia of pharmaceutical technology. 3rd ed. New York: Informa Healthcare; 2007. p. 406\u201318."},{"issue":"10","key":"3529_CR61","doi-asserted-by":"publisher","first-page":"1131","DOI":"10.3109\/03639045.2011.561350","volume":"37","author":"K Dvo\u0159\u00e1\u010dkov\u00e1","year":"2011","unstructured":"Dvo\u0159\u00e1\u010dkov\u00e1 K, Rabi\u0161kov\u00e1 M, Musel\u00edk J, Gajdziok J, Bajerov\u00e1 M. Coated hard capsules as the pH-dependent drug transport systems to ileo-colonic compartment. Drug Dev Ind Pharm. 2011;37(10):1131\u201340. https:\/\/doi.org\/10.3109\/03639045.2011.561350.","journal-title":"Drug Dev Ind Pharm."},{"issue":"2","key":"3529_CR62","first-page":"191","volume":"67","author":"K Dvor\u00e1ckov\u00e1","year":"2010","unstructured":"Dvor\u00e1ckov\u00e1 K, Rabiskov\u00e1 M, Gajdziok J, Vetch\u00fd D, Musel\u00edk J, Bernatoniene J, et al. Coated capsules for drug targeting to proximal and distal part of human intestine. Acta Pol Pharm. 2010;67(2):191\u20139.","journal-title":"Acta Pol Pharm."},{"key":"3529_CR63","unstructured":"Thoma K, Bechtold K. Enteric coated hard gelatin capsules. Capsugel Tech Bull [Internet]. 1986 [cited 2026 Jun 13]:1\u201316. Available from: https:\/\/owndoc.com\/pdf\/enteric-coated-hard-gelatin-capsules.pdf."},{"key":"3529_CR64","unstructured":"Leiberich R, Gabler W, inventors; R.P. Scherer GmbH, assignee. Gastric juice resistant gelatin capsules and a process for the production thereof.\u00a0United States patent US 3,959,540. 1976 May 25."},{"issue":"1","key":"3529_CR65","doi-asserted-by":"publisher","first-page":"36","DOI":"10.5530\/jyp.2015.1.7","volume":"7","author":"MM Al-Tabakha","year":"2014","unstructured":"Al-Tabakha MM, Arida AI, Fahelelbom KMS, Sadek B, Abu Jarad RA. Performances of new generation of delayed release capsules. J Young Pharm. 2014;7(1):36\u201344. https:\/\/doi.org\/10.5530\/jyp.2015.1.7.","journal-title":"J Young Pharm"},{"issue":"1","key":"3529_CR66","doi-asserted-by":"publisher","first-page":"83","DOI":"10.1016\/S0378-5173(01)00871-7","volume":"231","author":"ET Cole","year":"2002","unstructured":"Cole ET, Scott RA, Connor AL, Wilding IR, Petereit HU, Schminke C, et al. Enteric coated HPMC capsules designed to achieve intestinal targeting. Int J Pharm. 2002;231(1):83\u201395. https:\/\/doi.org\/10.1016\/S0378-5173(01)00871-7.","journal-title":"Int J Pharm"},{"key":"3529_CR67","unstructured":"Pagay SN, inventor; Banner Gelatin Products Corp., assignee. Enteric coated soft capsules and method of preparation thereof. United States patent US 5,330,759. 1994 Jul 19."},{"key":"3529_CR68","unstructured":"Vertommen J, Martina MS, inventors; Capsugel Belgium NV, applicant. Enteric coating for soft capsule. International patent application WO 2014\/140991 A1. 2014 Sept 18."},{"issue":"1\u20132","key":"3529_CR69","doi-asserted-by":"publisher","first-page":"283","DOI":"10.1016\/j.ijpharm.2014.12.060","volume":"484","author":"J Al-Gousous","year":"2015","unstructured":"Al-Gousous J, Penning M, Langguth P. Molecular insights into shellac film coats from different aqueous shellac salt solutions and effect on disintegration of enteric-coated soft gelatin capsules. Int J Pharm. 2015;484(1\u20132):283\u201391. https:\/\/doi.org\/10.1016\/j.ijpharm.2014.12.060.","journal-title":"Int J Pharm."},{"issue":"3","key":"3529_CR70","doi-asserted-by":"publisher","first-page":"313","DOI":"10.1016\/S0939-6411(03)00002-X","volume":"55","author":"R Pissinati","year":"2003","unstructured":"Pissinati R, Oliveira WP. Enteric coating of soft gelatin capsules by spouted bed: effect of operating conditions on coating efficiency and on product quality. Eur J Pharm Biopharm. 2003;55(3):313\u201321. https:\/\/doi.org\/10.1016\/S0939-6411(03)00002-X.","journal-title":"Eur J Pharm Biopharm."},{"key":"3529_CR71","doi-asserted-by":"publisher","first-page":"17","DOI":"10.1016\/0378-5173(94)00169-6","volume":"113","author":"LA Felton","year":"1995","unstructured":"Felton LA, Haase MM, Shah NH, Zhang G, Infeld MH, Malick AW, et al. Physical and enteric properties of soft gelatin capsules coated with Eudragit L30 D-55. Int J Pharm. 1995;113:17\u201324. https:\/\/doi.org\/10.1016\/0378-5173(94)00169-6.","journal-title":"Int J Pharm"},{"issue":"7","key":"3529_CR72","doi-asserted-by":"publisher","first-page":"3806","DOI":"10.1007\/s10853-016-0637-6","volume":"52","author":"SS Lal","year":"2017","unstructured":"Lal SS, Tanna P, Kale S, Mhaske ST. Kafirin polymer film for enteric coating on HPMC and gelatin capsules. J Mater Sci. 2017;52(7):3806\u201320. https:\/\/doi.org\/10.1007\/s10853-016-0637-6.","journal-title":"J Mater Sci"},{"issue":"5","key":"3529_CR73","first-page":"34","volume":"15","author":"H Benameur","year":"2015","unstructured":"Benameur H. Enteric capsule drug delivery technology: achieving protection without coating. Drug Dev Deliv. 2015;15(5):34\u20137.","journal-title":"Drug Dev Deliv."},{"key":"3529_CR74","doi-asserted-by":"publisher","first-page":"163","DOI":"10.1016\/j.ejps.2019.01.012","volume":"129","author":"M Grimm","year":"2019","unstructured":"Grimm M, Ball K, Scholz E, Schneider F, Sivert A, Benameur H, et al. Characterization of the gastrointestinal transit and disintegration behavior of floating and sinking acid-resistant capsules using a novel MRI labeling technique. Eur J Pharm Sci. 2019;129:163\u201372. https:\/\/doi.org\/10.1016\/j.ejps.2019.01.012.","journal-title":"Eur J Pharm Sci."},{"key":"3529_CR75","unstructured":"Chang RJ, Wu CJ, Lin YH, inventors; Dah Feng Capsule Industry Co., Ltd., assignee. Acid resistant capsule shell composition, acid resistant capsule shell and its preparing process. United States patent US 9,452,141 B1. 2016 Sept 27."},{"issue":"11","key":"3529_CR76","doi-asserted-by":"publisher","DOI":"10.3390\/pharmaceutics15112592","volume":"15","author":"JA Afonso Urich","year":"2023","unstructured":"Afonso Urich JA, Fedorko A, H\u00f6lzer B, Khinast J. Evidence of reliable gastro-resistance of novel enteric ready-to-fill capsules simplifying pharmaceutical manufacturing. Pharmaceutics. 2023;15(11):2592. https:\/\/doi.org\/10.3390\/pharmaceutics15112592.","journal-title":"Pharmaceutics"},{"key":"3529_CR77","unstructured":"CapsCanada. AR-CAPS\u00ae acid resistant capsules. Windsor (ON): CapsCanada. [cited 2026 Jun 13]. Available from: https:\/\/capscanada.com\/acid-resistant-capsules\/."},{"key":"3529_CR78","unstructured":"Farmacapsulas. Acid resistant capsules: AR Caps. Barranquilla: Farmacapsulas; 2017 [cited 2026 Jun 13]. Available from: https:\/\/www.pharmaceutical-tech.com\/products\/farmacapsulas\/acid-resistant-capsules-ar-caps."},{"key":"3529_CR79","unstructured":"Pharmaceutical Technology Editors. Capsugel launches enTRinsic drug delivery technology platform. Pharm Technol [Internet]. 2015 [cited 2026 Jun 13]. Available from: https:\/\/www.pharmtech.com\/view\/capsugel-launches-entrinsic-drug-delivery-technology-platform."},{"key":"3529_CR80","unstructured":"Lonza Pharma & Biotech. Capsugel Vcaps Enteric. Pharm Technol Eur [Internet]. 2018 [cited 2026 Jun 13];30(7):41. Available from: http:\/\/alfresco-static-files.s3.amazonaws.com\/alfresco_images\/pharma\/2018\/10\/11\/0592de88-9026-4c61-b660-f5fd790b7cea\/PharmTech_Europe_July2018.pdf#page=41."},{"key":"3529_CR81","unstructured":"Lonza. DRcaps designed release [Internet]. Basel: Lonza; [cited 2026 Jun 13]. Available from: https:\/\/www.capsugel.com\/nutraceutical-solutions\/hard-empty-capsules\/hpmc-designed-release-capsule."},{"key":"3529_CR82","unstructured":"Amo R. DRcaps capsules achieve delayed release properties for nutritional ingredients in human clinical study. Capsugel; 2021 [cited 2026 Jun 13]. Available from: https:\/\/www.pharmaexcipients.com\/wp-content\/uploads\/2021\/01\/DRcaps%C2%AE-Capsules-Achieve-Delayed-Release-Properties-for-Nutritional-Ingredients-in-Human-Clinical-Study.pdf."},{"key":"3529_CR83","unstructured":"Embocaps by Suheung. The Embocaps capsule design [Internet]. Cheongju (Korea): Suheung Co., Ltd.; c2019 [cited 2026 Jun 13]. Available from: https:\/\/www.embocaps.com\/sub\/capsule-advantage-design.php."},{"key":"3529_CR84","unstructured":"Embocaps by Suheung. Embocaps AP: acid resistant hypromellose capsules [brochure on the Internet]. Cheongju (Korea): Suheung Co., Ltd.; 2023 [cited 2026 Jun 13]:4. Available from: https:\/\/www.embocaps.com\/sub\/brochure\/products-ap.pdf."},{"key":"3529_CR85","unstructured":"Dah Feng Capsule Industry Co., Ltd. BioVXR acid resistant capsules [brochure on the Internet]. Taichung (Taiwan): Dah Feng Capsule Industry Co., Ltd.; 2022 [cited 2026 Jun 13]:4. Available from: https:\/\/www.dfc.com.tw\/archive\/product\/item\/files\/BioVXR%20brochure%202022.pdf."},{"issue":"11","key":"3529_CR86","doi-asserted-by":"publisher","first-page":"1398","DOI":"10.3390\/ph15111398","volume":"15","author":"A Franc","year":"2022","unstructured":"Franc A, Vetch\u00fd D, F\u00fcl\u00f6pov\u00e1 N. Commercially available enteric empty hard capsules, production technology and application. Pharmaceuticals (Basel). 2022;15(11):1398. https:\/\/doi.org\/10.3390\/ph15111398.","journal-title":"Pharmaceuticals (Basel)."},{"issue":"A1","key":"3529_CR87","first-page":"27","volume":"20060165778","author":"EM Hassan","year":"2006","unstructured":"Hassan EM, Fatmi AA, Chidambaram N. Enteric composition for the manufacture of soft capsule wall. United States patent application US. 2006;20060165778(A1):27.","journal-title":"United States patent application US"},{"issue":"6","key":"3529_CR88","doi-asserted-by":"publisher","first-page":"324","DOI":"10.1691\/ph.2017.6186","volume":"72","author":"B Maciejewski","year":"2017","unstructured":"Maciejewski B, Weitschies W, Schneider F, Sznitowska M. Gastroresistant gelatin films prepared by addition of cellulose acetate phthalate. Pharmazie. 2017;72(6):324\u20138. https:\/\/doi.org\/10.1691\/ph.2017.6186.","journal-title":"Pharmazie"},{"key":"3529_CR89","unstructured":"Tanner KE, Getz JJ, Burnett SW, Youngblood E, Draper PR. Film forming compositions comprising modified starches and iota-carrageenan and methods for manufacturing soft capsules using same. International patent application WO 2001003677 A1. 2001."},{"key":"3529_CR90","unstructured":"Hausmanns S, Kiy T, Tomka I, Muller R. Soft capsules comprising a starch mixture having a reduced degree of branching. United States patent application US 20040087669 A1. 2004."},{"key":"3529_CR91","unstructured":"Gilleland GM, Turner JL, Patton PA, Harrison MD. Modified starch as a replacement for gelatin in soft gel films and capsules. United States patent US 6375981 B1. 2002."},{"issue":"12","key":"3529_CR92","doi-asserted-by":"publisher","first-page":"4516","DOI":"10.1002\/jps.23315","volume":"101","author":"Z Misic","year":"2012","unstructured":"Misic Z, Muffler K, Sydow G, Kuentz M. Novel starch-based PVA thermoplastic capsules for hydrophilic lipid-based formulations. J Pharm Sci. 2012;101(12):4516\u201328. https:\/\/doi.org\/10.1002\/jps.23315.","journal-title":"J Pharm Sci."},{"key":"3529_CR93","unstructured":"Kubodera M. Glucomannan\/polyhydric alcohol composition and film prepared therefrom. United States patent US 4851394 A. 1989."},{"key":"3529_CR94","unstructured":"Angel M, Kolter K, Sanner A, Gotsche M. Soft capsules comprising polymers of vinyl esters and polyethers, the use and production thereof. United States patent US 6770293 B2. 2004."},{"key":"3529_CR95","unstructured":"Winston PE, Miskiel FJ, Valli RC. Composition and process for gelatin-free soft capsules. United States patent US 5342626 A. 1994."},{"issue":"7","key":"3529_CR96","doi-asserted-by":"publisher","DOI":"10.3390\/ma13071771","volume":"13","author":"B Maciejewski","year":"2020","unstructured":"Maciejewski B, Arumughan V, Larsson A, Sznitowska M. Prototype gastro-resistant soft gelatin films and capsules: imaging and performance in vitro. Materials (Basel). 2020;13(7):1771. https:\/\/doi.org\/10.3390\/ma13071771.","journal-title":"Materials (Basel)"},{"key":"3529_CR97","unstructured":"U.S. Food and Drug Administration. Stavzor (valproic acid) delayed-release capsules: prescribing information. Silver Spring (MD): U.S. Food and Drug Administration; 2021 [cited 2026 Jun 13]. Available from: https:\/\/www.accessdata.fda.gov\/drugsatfda_docs\/label\/2021\/022152s009lbl.pdf"},{"issue":"2\u20133","key":"3529_CR98","doi-asserted-by":"publisher","first-page":"207","DOI":"10.1016\/j.ejps.2004.10.011","volume":"24","author":"E Mehuys","year":"2005","unstructured":"Mehuys E, Remon JP, Vervaet C. Production of enteric capsules by means of hot-melt extrusion. Eur J Pharm Sci. 2005;24(2\u20133):207\u201312. https:\/\/doi.org\/10.1016\/j.ejps.2004.10.011.","journal-title":"Eur J Pharm Sci."},{"issue":"1","key":"3529_CR99","doi-asserted-by":"publisher","first-page":"264","DOI":"10.1016\/j.ejpb.2007.11.001","volume":"69","author":"GP Andrews","year":"2008","unstructured":"Andrews GP, Jones DS, Diak OA, McCoy CP, Watts AB, McGinity JW. The manufacture and characterisation of hot-melt extruded enteric tablets. Eur J Pharm Biopharm. 2008;69(1):264\u201373. https:\/\/doi.org\/10.1016\/j.ejpb.2007.11.001.","journal-title":"Eur J Pharm Biopharm."},{"issue":"2","key":"3529_CR100","doi-asserted-by":"publisher","first-page":"352","DOI":"10.1016\/j.ejpb.2009.09.008","volume":"74","author":"SU Schilling","year":"2010","unstructured":"Schilling SU, Shah NH, Waseem Malick A, McGinity JW. Properties of melt extruded enteric matrix pellets. Eur J Pharm Biopharm. 2010;74(2):352\u201361. https:\/\/doi.org\/10.1016\/j.ejpb.2009.09.008.","journal-title":"Eur J Pharm Biopharm"},{"issue":"12","key":"3529_CR101","doi-asserted-by":"publisher","first-page":"1357","DOI":"10.1517\/17425240802583421","volume":"5","author":"MA Repka","year":"2008","unstructured":"Repka MA, Majumdar S, Kumar Battu S, Srirangam R, Upadhye SB. Applications of hot-melt extrusion for drug delivery. Expert Opin Drug Deliv. 2008;5(12):1357\u201376. https:\/\/doi.org\/10.1517\/17425240802583421.","journal-title":"Expert Opin Drug Deliv."},{"issue":"3","key":"3529_CR102","doi-asserted-by":"publisher","first-page":"386","DOI":"10.3390\/polym16030386","volume":"16","author":"H Iqbal","year":"2024","unstructured":"Iqbal H, Fernandes Q, Idoudi S, Basineni R, Billa N. Status of polymer fused deposition modeling (FDM)-based three-dimensional printing (3DP) in the pharmaceutical industry. Polymers (Basel). 2024;16(3):386. https:\/\/doi.org\/10.3390\/polym16030386.","journal-title":"Polymers (Basel)."},{"issue":"2","key":"3529_CR103","doi-asserted-by":"publisher","first-page":"427","DOI":"10.1007\/s11095-016-2073-3","volume":"34","author":"TC Okwuosa","year":"2017","unstructured":"Okwuosa TC, Pereira BC, Arafat B, Cieszynska M, Isreb A, Alhnan MA. Fabricating a shell-core delayed release tablet using dual FDM 3D printing for patient-centred therapy. Pharm Res. 2017;34(2):427\u201337. https:\/\/doi.org\/10.1007\/s11095-016-2073-3.","journal-title":"Pharm Res."},{"issue":"1\u20132","key":"3529_CR104","doi-asserted-by":"publisher","first-page":"21","DOI":"10.1016\/j.ijpharm.2017.05.021","volume":"527","author":"A Goyanes","year":"2017","unstructured":"Goyanes A, Fina F, Martorana A, Sedough D, Gaisford S, Basit AW. Development of modified release 3D printed tablets (printlets) with pharmaceutical excipients using additive manufacturing. Int J Pharm. 2017;527(1\u20132):21\u201330. https:\/\/doi.org\/10.1016\/j.ijpharm.2017.05.021.","journal-title":"Int J Pharm."},{"issue":"35","key":"3529_CR105","doi-asserted-by":"publisher","first-page":"2814","DOI":"10.2174\/0113816128275872231105183036","volume":"29","author":"A Saxena","year":"2023","unstructured":"Saxena A, Malviya R. 3D printable drug delivery systems: next-generation healthcare technology and regulatory aspects. Curr Pharm Des. 2023;29(35):2814\u201326. https:\/\/doi.org\/10.2174\/0113816128275872231105183036.","journal-title":"Curr Pharm Des."},{"issue":"3","key":"3529_CR106","doi-asserted-by":"publisher","first-page":"94","DOI":"10.3390\/compounds1030009","volume":"1","author":"MA Mahmood","year":"2021","unstructured":"Mahmood MA. 3D printing in drug delivery and biomedical applications: a state-of-the-art review. Compounds. 2021;1(3):94\u2013115. https:\/\/doi.org\/10.3390\/compounds1030009.","journal-title":"Compounds"},{"issue":"7","key":"3529_CR107","doi-asserted-by":"publisher","first-page":"6357","DOI":"10.3390\/ijms24076357","volume":"24","author":"EHY Lam","year":"2023","unstructured":"Lam EHY, Yu F, Zhu S, Wang Z. 3D bioprinting for next-generation personalized medicine. Int J Mol Sci. 2023;24(7):6357. https:\/\/doi.org\/10.3390\/ijms24076357.","journal-title":"Int J Mol Sci."},{"issue":"7","key":"3529_CR108","doi-asserted-by":"publisher","first-page":"973","DOI":"10.3390\/ph18070973","volume":"18","author":"Z Saleh-Bey-Kinj","year":"2025","unstructured":"Saleh-Bey-Kinj Z, Heller Y, Socratous G, Christodoulou P. 3D printing in oral drug delivery: technologies, clinical applications and future perspectives in precision medicine. Pharmaceuticals (Basel). 2025;18(7):973. https:\/\/doi.org\/10.3390\/ph18070973.","journal-title":"Pharmaceuticals (Basel)."},{"issue":"11","key":"3529_CR109","doi-asserted-by":"publisher","first-page":"3798","DOI":"10.1002\/jps.24587","volume":"104","author":"G Bruni","year":"2015","unstructured":"Bruni G, Maggi L, Tammaro L, Canobbio A, Di Lorenzo R, D\u2019Aniello S, et al. Fabrication, physico-chemical, and pharmaceutical characterization of budesonide-loaded electrospun fibers for drug targeting to the colon. J Pharm Sci. 2015;104(11):3798\u2013803. https:\/\/doi.org\/10.1002\/jps.24587.","journal-title":"J Pharm Sci."},{"issue":"10","key":"3529_CR110","doi-asserted-by":"publisher","first-page":"2127","DOI":"10.3390\/polym14102127","volume":"14","author":"V Friuli","year":"2022","unstructured":"Friuli V, Pisani S, Conti B, Bruni G, Maggi L. Tablet formulations of polymeric electrospun fibers for the controlled release of drugs with pH-dependent solubility. Polymers (Basel). 2022;14(10):2127. https:\/\/doi.org\/10.3390\/polym14102127.","journal-title":"Polymers (Basel)."},{"issue":"2","key":"3529_CR111","doi-asserted-by":"publisher","first-page":"131","DOI":"10.2478\/acph-2019-0014","volume":"69","author":"\u0160 Zupan\u010di\u010d","year":"2019","unstructured":"Zupan\u010di\u010d \u0160. Core-shell nanofibers as drug delivery systems. Acta Pharm. 2019;69(2):131\u201353. https:\/\/doi.org\/10.2478\/acph-2019-0014.","journal-title":"Acta Pharm"},{"issue":"4","key":"3529_CR112","doi-asserted-by":"publisher","first-page":"e1611","DOI":"10.1002\/wnan.1611","volume":"12","author":"P Vass","year":"2020","unstructured":"Vass P, Szab\u00f3 E, Domokos A, Hirsch E, Galata D, Farkas B, et al. Scale-up of electrospinning technology: applications in the pharmaceutical industry. Wiley Interdiscip Rev Nanomed Nanobiotechnol. 2020;12(4):e1611. https:\/\/doi.org\/10.1002\/wnan.1611.","journal-title":"Wiley Interdiscip Rev Nanomed Nanobiotechnol."},{"issue":"3","key":"3529_CR113","doi-asserted-by":"publisher","first-page":"153","DOI":"10.3923\/ajdd.2014.153.179","volume":"4","author":"P Ganesan","year":"2014","unstructured":"Ganesan P, Deepa John AJ, Sabapathy L, Duraikannu A. Review on microsphere. Am J Drug Discov Dev. 2014;4(3):153\u201379. https:\/\/doi.org\/10.3923\/ajdd.2014.153.179.","journal-title":"Am J Drug Discov Dev."},{"key":"3529_CR114","doi-asserted-by":"publisher","first-page":"122","DOI":"10.1016\/j.phrs.2016.05.016","volume":"110","author":"L Salvioni","year":"2016","unstructured":"Salvioni L, Fiandra L, Del Curto MD, Mazzucchelli S, Allevi R, Truffi M, et al. Oral delivery of insulin via polyethylene imine-based nanoparticles for colonic release allows glycemic control in diabetic rats. Pharmacol Res. 2016;110:122\u201330. https:\/\/doi.org\/10.1016\/j.phrs.2016.05.016.","journal-title":"Pharmacol Res."},{"key":"3529_CR115","doi-asserted-by":"publisher","first-page":"9","DOI":"10.1016\/j.supflu.2015.08.009","volume":"107","author":"A Tandya","year":"2016","unstructured":"Tandya A, Zhuang HQ, Mammucari R, Foster NR. Supercritical fluid micronization techniques for gastroresistant insulin formulations. J Supercrit Fluids. 2016;107:9\u201316. https:\/\/doi.org\/10.1016\/j.supflu.2015.08.009.","journal-title":"J Supercrit Fluids."},{"issue":"1","key":"3529_CR116","doi-asserted-by":"publisher","first-page":"24","DOI":"10.1080\/10717540802481349","volume":"16","author":"B Luppi","year":"2009","unstructured":"Luppi B, Bigucci F, Zecchi V, Cerchiara T. Gastroresistant microcapsules: new approaches for site-specific delivery of ketoprofen. Drug Deliv. 2009;16(1):24\u20139. https:\/\/doi.org\/10.1080\/10717540802481349.","journal-title":"Drug Deliv."},{"key":"3529_CR117","doi-asserted-by":"publisher","first-page":"286","DOI":"10.1016\/j.carbpol.2014.07.021","volume":"113","author":"FG Prezotti","year":"2014","unstructured":"Prezotti FG, Cury BSF, Evangelista RC. Mucoadhesive beads of gellan gum\/pectin intended to controlled delivery of drugs. Carbohydr Polym. 2014;113:286\u201395. https:\/\/doi.org\/10.1016\/j.carbpol.2014.07.021.","journal-title":"Carbohydr Polym."},{"issue":"8","key":"3529_CR118","doi-asserted-by":"publisher","first-page":"1004","DOI":"10.1016\/j.drudis.2015.03.002","volume":"20","author":"H Du","year":"2015","unstructured":"Du H, Liu M, Yang X, Zhai G. The design of pH-sensitive chitosan-based formulations for gastrointestinal delivery. Drug Discov Today. 2015;20(8):1004\u201311. https:\/\/doi.org\/10.1016\/j.drudis.2015.03.002.","journal-title":"Drug Discov Today."},{"issue":"6","key":"3529_CR119","doi-asserted-by":"publisher","first-page":"713","DOI":"10.1517\/17425247.2012.682148","volume":"9","author":"A Gulbake","year":"2012","unstructured":"Gulbake A, Jain SK. Chitosan: a potential polymer for colon-specific drug delivery system. Expert Opin Drug Deliv. 2012;9(6):713\u201329. https:\/\/doi.org\/10.1517\/17425247.2012.682148.","journal-title":"Expert Opin Drug Deliv"},{"key":"3529_CR120","doi-asserted-by":"publisher","first-page":"9","DOI":"10.1016\/j.biomaterials.2015.07.045","volume":"68","author":"N Shrestha","year":"2015","unstructured":"Shrestha N, Shahbazi MA, Ara\u00fajo F, M\u00e4kil\u00e4 E, Raula J, Kauppinen EI, et al. Multistage pH-responsive mucoadhesive nanocarriers prepared by aerosol flow reactor technology: a controlled dual protein-drug delivery system. Biomaterials. 2015;68:9\u201320. https:\/\/doi.org\/10.1016\/j.biomaterials.2015.07.045.","journal-title":"Biomaterials."},{"issue":"8","key":"3529_CR121","doi-asserted-by":"publisher","first-page":"1158","DOI":"10.1016\/j.jsps.2017.07.008","volume":"25","author":"JR Rodriguez Amado","year":"2017","unstructured":"Rodriguez Amado JR, Prada AL, Duarte JL, Keita H, da Silva HR, Ferreira AM, et al. Development, stability and in vitro delivery profile of new loratadine-loaded nanoparticles. Saudi Pharm J. 2017;25(8):1158\u201368. https:\/\/doi.org\/10.1016\/j.jsps.2017.07.008.","journal-title":"Saudi Pharm J."},{"key":"3529_CR122","doi-asserted-by":"publisher","first-page":"1456939","DOI":"10.3389\/fnano.2024.1456939","volume":"6","author":"P Ly","year":"2024","unstructured":"Ly P, Ly K, Phan H, Nguyen HHT, Duong V, Nguyen HV. Recent advances in surface decoration of nanoparticles in drug delivery. Front Nanotechnol. 2024;6:1456939. https:\/\/doi.org\/10.3389\/fnano.2024.1456939.","journal-title":"Front Nanotechnol."},{"issue":"1","key":"3529_CR123","doi-asserted-by":"publisher","first-page":"669","DOI":"10.1186\/s12951-024-02930-6","volume":"22","author":"Y Wang","year":"2024","unstructured":"Wang Y, Mo Y, Sun Y, Li J, An Y, Feng N, et al. Intestinal nanoparticle delivery and cellular response: a review of the bidirectional nanoparticle-cell interplay in mucosa based on physiochemical properties. J Nanobiotechnology. 2024;22(1):669. https:\/\/doi.org\/10.1186\/s12951-024-02930-6.","journal-title":"J Nanobiotechnology."},{"key":"3529_CR124","doi-asserted-by":"publisher","first-page":"15","DOI":"10.1007\/s10965-015-0662-1","volume":"22","author":"QB Wei","year":"2015","unstructured":"Wei QB, Fu F, Zhang YQ, Tang L. Synthesis and characterization of pH-responsive carboxymethyl chitosan-g-polyacrylic acid hydrogels. J Polym Res. 2015;22:15. https:\/\/doi.org\/10.1007\/s10965-015-0662-1.","journal-title":"J Polym Res."},{"key":"3529_CR125","doi-asserted-by":"publisher","first-page":"142","DOI":"10.1515\/epoly.2008.8.1.1636","volume":"8","author":"N Rasool","year":"2008","unstructured":"Rasool N, Yasin T, Akhter Z. Synthesis of carboxymethyl-chitosan\/acrylic acid hydrogel using silane crosslinker. e-Polym. 2008;8:142. https:\/\/doi.org\/10.1515\/epoly.2008.8.1.1636.","journal-title":"e-Polym"},{"key":"3529_CR126","doi-asserted-by":"publisher","first-page":"478","DOI":"10.1016\/j.msec.2016.05.031","volume":"67","author":"O Lv","year":"2016","unstructured":"Lv O, Tao Y, Qin Y, Chen C, Pan Y, Deng L, et al. Highly fluorescent and morphology-controllable graphene quantum dots-chitosan hybrid xerogels for in vivo imaging and pH-sensitive drug carrier. Mater Sci Eng C. 2016;67:478\u201385. https:\/\/doi.org\/10.1016\/j.msec.2016.05.031.","journal-title":"Mater Sci Eng C."},{"issue":"3","key":"3529_CR127","doi-asserted-by":"publisher","first-page":"1055","DOI":"10.1016\/j.carbpol.2012.01.070","volume":"88","author":"A Islam","year":"2012","unstructured":"Islam A, Yasin T. Controlled delivery of drug from pH-sensitive chitosan\/poly(vinyl alcohol) blend. Carbohydr Polym. 2012;88(3):1055\u201360. https:\/\/doi.org\/10.1016\/j.carbpol.2012.01.070.","journal-title":"Carbohydr Polym"},{"issue":"5","key":"3529_CR128","doi-asserted-by":"publisher","first-page":"4184","DOI":"10.1002\/app.35392","volume":"124","author":"A Islam","year":"2012","unstructured":"Islam A, Yasin T, Bano I, Riaz M. Controlled release of aspirin from pH-sensitive chitosan\/poly(vinyl alcohol) hydrogel. J Appl Polym Sci. 2012;124(5):4184\u201392. https:\/\/doi.org\/10.1002\/app.35392.","journal-title":"J Appl Polym Sci"},{"issue":"4","key":"3529_CR129","doi-asserted-by":"publisher","DOI":"10.3390\/polym9040137","volume":"9","author":"M Rizwan","year":"2017","unstructured":"Rizwan M, Yahya R, Hassan A, Yar M, Azzahari AD, Selvanathan V, et al. pH-sensitive hydrogels in drug delivery: brief history, properties, swelling, and release mechanism, material selection and applications. Polymers. 2017;9(4):137. https:\/\/doi.org\/10.3390\/polym9040137.","journal-title":"Polymers"},{"issue":"11","key":"3529_CR130","doi-asserted-by":"publisher","first-page":"1451","DOI":"10.3390\/polym17111451","volume":"17","author":"G Patroklou","year":"2025","unstructured":"Patroklou G, Triantafyllopoulou E, Goula PE, Karali V, Chountoulesi M, Valsami G, et al. pH-responsive hydrogels: recent advances in pharmaceutical applications. Polymers (Basel). 2025;17(11):1451. https:\/\/doi.org\/10.3390\/polym17111451.","journal-title":"Polymers (Basel)."},{"issue":"1","key":"3529_CR131","doi-asserted-by":"publisher","first-page":"9","DOI":"10.1097\/MOG.0000000000001064","volume":"41","author":"C Yeung","year":"2025","unstructured":"Yeung C, McCoubrey LE, Basit AW. Advances in colon-targeted drug technologies. Curr Opin Gastroenterol. 2025;41(1):9\u201315. https:\/\/doi.org\/10.1097\/MOG.0000000000001064.","journal-title":"Curr Opin Gastroenterol"}],"container-title":["AAPS PharmSciTech"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/link.springer.com\/content\/pdf\/10.1208\/s12249-026-03529-w.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/link.springer.com\/article\/10.1208\/s12249-026-03529-w","content-type":"text\/html","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/link.springer.com\/content\/pdf\/10.1208\/s12249-026-03529-w.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,9,8]],"date-time":"2026-09-08T16:44:58Z","timestamp":1788885898000},"score":1,"resource":{"primary":{"URL":"https:\/\/link.springer.com\/10.1208\/s12249-026-03529-w"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,9,8]]},"references-count":131,"journal-issue":{"issue":"7","published-online":{"date-parts":[[2026,10]]}},"alternative-id":["3529"],"URL":"https:\/\/doi.org\/10.1208\/s12249-026-03529-w","relation":{},"ISSN":["1530-9932"],"issn-type":[{"value":"1530-9932","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,9,8]]},"assertion":[{"value":"7 May 2026","order":1,"name":"received","label":"Received","group":{"name":"ArticleHistory","label":"Article History"}},{"value":"29 July 2026","order":2,"name":"accepted","label":"Accepted","group":{"name":"ArticleHistory","label":"Article History"}},{"value":"8 September 2026","order":3,"name":"first_online","label":"First Online","group":{"name":"ArticleHistory","label":"Article History"}},{"value":"The authors declare no financial or non-financial interests that are directly or indirectly related to the work submitted for publication.","order":1,"name":"Ethics","label":"Conflict of Interest","group":{"name":"EthicsHeading","label":"Declarations"}}],"article-number":"270"}}