{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,5,8]],"date-time":"2026-05-08T05:10:13Z","timestamp":1778217013180,"version":"3.51.4"},"reference-count":47,"publisher":"MDPI AG","issue":"5","license":[{"start":{"date-parts":[[2026,5,6]],"date-time":"2026-05-06T00:00:00Z","timestamp":1778025600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/100031663","name":"Saudi Food and Drug Authority","doi-asserted-by":"crossref","id":[{"id":"10.13039\/100031663","id-type":"DOI","asserted-by":"crossref"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Antibiotics"],"abstract":"<jats:p>Background\/Objectives: Vancomycin hydrochloride (HCl) for injection is a vital antibiotic for severe infections. Vancomycin is an indispensable first-line antibiotic for life-threatening infections like methicillin-resistant Staphylococcus aureus (MRSA) bacteremia and serves as a key oral agent for severe Clostridium difficile infection. This makes rigorous quality monitoring essential. Concerns about the efficacy of certain generic vancomycin HCl products have prompted regulatory agencies to increase post-market evaluations to ensure patient safety. Aligned with these efforts, this study aimed to comparatively evaluate the potency and quality of five randomly procured generic intravenous vancomycin HCl products marketed in Saudi Arabia. Methods: Using both microbiological and chemical methodologies as recommended by the US Pharmacopeia (USP) guidelines. Results: The microbiological assay, utilizing the USP \u201cAntibiotics\u2014Microbial Assay\u201d method using Bacillus subtilis ATCC 6633 via the agar diffusion technique, demonstrated a strong linear correlation (R2 &gt; 0.98) between inhibition zone diameters and vancomycin concentration. All five tested generics products showed compliance (~ 105%) with USP &lt;81&gt; biological activity standards. For chemical quantification, a High-Performance Liquid Chromatography-Diode Array Detector (HPLC-DAD) method was developed and validated according to ICH Q2(R2) guidance. This method showed excellent linearity (R2 = 0.998), accuracy (96.9\u2013102%), and good precision. Conclusions: Both methods confirmed the potency of the tested generics within USP limits. However, minor variations observed between microbiological and chemical results highlight the importance of employing complementary techniques for comprehensive quality assessment. These findings underscore the importance of robust regulatory frameworks and ongoing post-market surveillance to ensure the continued safety, efficacy, and availability of quality-assured generic antibiotics in the Saudi market.<\/jats:p>","DOI":"10.3390\/antibiotics15050470","type":"journal-article","created":{"date-parts":[[2026,5,7]],"date-time":"2026-05-07T10:39:47Z","timestamp":1778150387000},"page":"470","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Dual Analytical Evaluation of Generic Intravenous Vancomycin HCl in Saudi Arabia Using Microbiological and HPLC-DAD Approaches"],"prefix":"10.3390","volume":"15","author":[{"ORCID":"https:\/\/orcid.org\/0009-0001-2301-4793","authenticated-orcid":false,"given":"Haya S.","family":"Alzeer","sequence":"first","affiliation":[{"name":"Saudi Food and Drug Authority (SFDA), Riyadh 13513, Saudi Arabia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Amani T.","family":"Alsufyani","sequence":"additional","affiliation":[{"name":"Saudi Food and Drug Authority (SFDA), Riyadh 13513, Saudi Arabia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Mai S.","family":"Alwathnani","sequence":"additional","affiliation":[{"name":"Department of Pharmaceutics, College of Pharmacy, Prince Sattam Bin Abdulaziz University (PSAU), Al-Kharj 16273, Saudi Arabia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0908-7141","authenticated-orcid":false,"given":"Afnan","family":"Althobaiti","sequence":"additional","affiliation":[{"name":"Saudi Food and Drug Authority (SFDA), Riyadh 13513, Saudi Arabia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Manal","family":"Almusa","sequence":"additional","affiliation":[{"name":"Saudi Food and Drug Authority (SFDA), Riyadh 13513, Saudi Arabia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0009-0002-7363-6336","authenticated-orcid":false,"given":"Fatimah M.","family":"Alamri","sequence":"additional","affiliation":[{"name":"Department of Chemistry, College of Science, King Khalid University (KKU), Abha 62529, Saudi Arabia"},{"name":"Department of Chemistry, College of Science, University of Bisha (BU), Bisha 61922, Saudi Arabia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Haneen H.","family":"Aldossari","sequence":"additional","affiliation":[{"name":"Department of Biochemistry, College of Science, King Saud University (KSU), Riyadh 11451, Saudi Arabia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Yahya M.","family":"Alshehri","sequence":"additional","affiliation":[{"name":"Saudi Food and Drug Authority (SFDA), Riyadh 13513, Saudi Arabia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Lenah E.","family":"Mukhtar","sequence":"additional","affiliation":[{"name":"Saudi Food and Drug Authority (SFDA), Riyadh 13513, Saudi Arabia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Fahad M.","family":"Alreshoodi","sequence":"additional","affiliation":[{"name":"Saudi Food and Drug Authority (SFDA), Riyadh 13513, Saudi Arabia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Fahad S.","family":"Aldawsari","sequence":"additional","affiliation":[{"name":"Saudi Food and Drug Authority (SFDA), Riyadh 13513, Saudi Arabia"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2026,5,6]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"8321834","DOI":"10.1155\/2019\/8321834","article-title":"Methicillin-Resistant Staphylococcus aureus (MRSA): Prevalence and Antimicrobial Sensitivity Pattern among Patients\u2014A Multicenter Study in Asmara, Eritrea","volume":"2019","author":"Garoy","year":"2019","journal-title":"Can. 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