{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,19]],"date-time":"2026-09-19T04:02:58Z","timestamp":1789790578612,"version":"4.0.1"},"reference-count":22,"publisher":"MDPI AG","issue":"12","license":[{"start":{"date-parts":[[2025,6,16]],"date-time":"2025-06-16T00:00:00Z","timestamp":1750032000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Molecules"],"abstract":"<jats:p>The sterility of ophthalmic drugs is a fundamental requirement for ensuring patient safety, and as such, it is subject to stringent regulatory standards. However, significant gaps remain regarding the effect of sterilization techniques on the impurity profile and relative content of active pharmaceutical ingredients (API). Previous research involving a set of five APIs used in ophthalmic preparations (dexamethasone, methylprednisolone, aciclovir, tetracycline hydrochloride, and triamcinolone) demonstrated that gamma irradiation led to the formation of specific impurities in the corticosteroids, dexamethasone and methylprednisolone. This study aims to further explore the effect of both gamma and electron beam (E-beam) irradiation on the impurity profiles of these APIs under varying conditions, with and without dry ice. The analyses were conducted using high-performance liquid chromatography with ultraviolet\/visible light (UV\/VIS) detection and the effect of sterilization conditions was assessed in accordance with the assay and related substances test outlined in the European Pharmacopoeia (Ph. Eur.). Additionally, this study investigated whether exposure in a controlled atmosphere with reduced oxygen or water content could mitigate the formation of impurities and influence the stability of the compounds. The results indicated a protective effect of low-temperature and low-oxygen environments during both gamma and E-beam irradiation but no effect of dry conditions.<\/jats:p>","DOI":"10.3390\/molecules30122605","type":"journal-article","created":{"date-parts":[[2025,6,16]],"date-time":"2025-06-16T05:28:33Z","timestamp":1750051713000},"page":"2605","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":2,"title":["On the Stability of Steroids upon Gamma and E-Beam Irradiation and the Protective Effect of Inert Conditions"],"prefix":"10.3390","volume":"30","author":[{"given":"Quinten","family":"Speleers","sequence":"first","affiliation":[{"name":"Pharmaceutical Analysis, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven\u2014University of Leuven, Herestraat 49, O&N2, PB 923, 3000 Leuven, Belgium"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Anke","family":"Meyers","sequence":"additional","affiliation":[{"name":"Pharmaceutical Analysis, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven\u2014University of Leuven, Herestraat 49, O&N2, PB 923, 3000 Leuven, Belgium"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Homaira","family":"Rashid","sequence":"additional","affiliation":[{"name":"Pharmaceutical Analysis, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven\u2014University of Leuven, Herestraat 49, O&N2, PB 923, 3000 Leuven, Belgium"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0007-4294-5124","authenticated-orcid":false,"given":"Yannick","family":"Dubbelboer","sequence":"additional","affiliation":[{"name":"Pharmaceutical Analysis, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven\u2014University of Leuven, Herestraat 49, O&N2, PB 923, 3000 Leuven, Belgium"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Elias","family":"Vanneste","sequence":"additional","affiliation":[{"name":"Pharmaceutical Analysis, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven\u2014University of Leuven, Herestraat 49, O&N2, PB 923, 3000 Leuven, Belgium"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Bart","family":"Croonenborghs","sequence":"additional","affiliation":[{"name":"Sterigenics NV, a Sotera Health Division, 2015 Spring Road 650, Oak Brook, IL 60523, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Annick","family":"Gillet","sequence":"additional","affiliation":[{"name":"Sterigenics NV, a Sotera Health Division, 2015 Spring Road 650, Oak Brook, IL 60523, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Aaron","family":"DeMent","sequence":"additional","affiliation":[{"name":"Sterigenics NV, a Sotera Health Division, 2015 Spring Road 650, Oak Brook, IL 60523, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-9583-984X","authenticated-orcid":false,"given":"Ann","family":"Van Schepdael","sequence":"additional","affiliation":[{"name":"Pharmaceutical Analysis, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven\u2014University of Leuven, Herestraat 49, O&N2, PB 923, 3000 Leuven, Belgium"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Erik","family":"Haghedooren","sequence":"additional","affiliation":[{"name":"Sterigenics NV, a Sotera Health Division, 2015 Spring Road 650, Oak Brook, IL 60523, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2025,6,16]]},"reference":[{"key":"ref_1","unstructured":"European Commission (2022). The Rules Governing Medicinal Products in the European Union Volume 4 EU Guidelines for Good Manufacturing Practice for Medicinal Products for Human and Veterinary Use, European Commission. Available online: https:\/\/health.ec.europa.eu\/document\/download\/e05af55b-38e9-42bf-8495-194bbf0b9262_en?filename=20220825_gmp-an1_en_0.pdf."},{"key":"ref_2","unstructured":"European Medicines Agency (2019). Guideline on the Sterilisation of the Medicinal Product, Active Substance, Excipient and Primary Container, European Medicines Agency. Available online: https:\/\/www.ema.europa.eu\/en\/documents\/scientific-guideline\/guideline-sterilisation-medicinal-product-active-substance-excipient-and-primary-container_en.pdf."},{"key":"ref_3","unstructured":"(2023). General Texts: 5.1.1. Methods of Preparation of Sterile Products. European Pharmacopoeia 11.8, EDQM."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"109795","DOI":"10.1016\/j.radphyschem.2021.109795","article-title":"Irradiation of Pharmaceuticals: A Literature Review","volume":"190","author":"Jacobs","year":"2022","journal-title":"Radiat. Phys. Chem."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"1097","DOI":"10.2174\/1573411016999200617144806","article-title":"Radiation Sterilization of Antibiotics in Solid State","volume":"17","author":"Zalewski","year":"2021","journal-title":"Curr. Anal. Chem."},{"key":"ref_6","first-page":"219","article-title":"The Role of Pharmaceutical Analysis in Ensuring the Safety of Drug Radiation Sterilization","volume":"80","author":"Kaczmarek","year":"2023","journal-title":"Acta Pol. Pharm.\u2014Drug Res."},{"key":"ref_7","doi-asserted-by":"crossref","unstructured":"McKeen, L. (2012). Introduction to Food Irradiation and Medical Sterilization. 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(2010). Inerting in the Chemical Industry, Hydrocarbon Processing."},{"key":"ref_17","unstructured":"(2023). Monograph Dexamethasone. European Pharmacopoeia, EDQM. [11th ed.]."},{"key":"ref_18","unstructured":"(2023). Monograph Methylprednisolone. European Pharmacopoeia, EDQM. [11th ed.]."},{"key":"ref_19","unstructured":"(2023). Monograph Tetracycline Hydrochloride. European Pharmacopoeia, EDQM. [11th ed.]."},{"key":"ref_20","first-page":"203","article-title":"Radiation Effects on Pharmaceuticals","volume":"35","year":"2010","journal-title":"FABAD J. Pharm. Sci."},{"key":"ref_21","unstructured":"(2023). Monograph Aciclovir. European Pharmacopoeia, EDQM. [11th ed.]."},{"key":"ref_22","unstructured":"(2023). Monograph Triamcinolone. European Pharmacopoeia, EDQM. [11th ed.]."}],"container-title":["Molecules"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1420-3049\/30\/12\/2605\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,9]],"date-time":"2025-10-09T17:52:37Z","timestamp":1760032357000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1420-3049\/30\/12\/2605"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2025,6,16]]},"references-count":22,"journal-issue":{"issue":"12","published-online":{"date-parts":[[2025,6]]}},"alternative-id":["molecules30122605"],"URL":"https:\/\/doi.org\/10.3390\/molecules30122605","relation":{},"ISSN":["1420-3049"],"issn-type":[{"value":"1420-3049","type":"electronic"}],"subject":[],"published":{"date-parts":[[2025,6,16]]}}}