Quality Evaluation of Azithromycin Oral Solid Dosage Forms in Nigeria: In Vivo-In Vitro Correlation Study

Background: Azithromycin is used for bacterial infections, such as respiratory tract and genitourinary tract infections, and has also been effective for preventing maternal sepsis during vaginal birth in some settings.The availability of low-cost azithromycin products of the required pharmaceutical quality is crucial for a successful campaign against maternal sepsis-related death.This study aimed to evaluate the quality of the azithromycin oral solid dosage forms manufactured and marketed in Nigeria.Methods: Three locally manufactured generic products and the innovator product of azithromycin tablets/capsules were subjected to physicochemical tests in accordance with United States Pharmacopeia (USP) specifications.Dissolution profiles of the products in 0.1 N hydrochloric acid (HCl) and phosphate buffer (pH 6.0) were compared using model-dependent and model-independent approaches.The innovator and generic products with similar dissolution profiles were subjected to a 2-g single-dose randomized two-period crossover bioavailability and bioequivalence study.Results: All products met USP specifications for weight uniformity, disintegration (10-15 min), drug content (99.8-101.1%),and dissolution in phosphate buffer 6.0 (> 75% dissolution in 45 min); However, one product failed the test for friability.The kinetic model with the best fit for the products was the Korsmeyer-Pappas model (R 2 = 0.7137-0.9562).Only one product (AZI-E) had a comparable dissolution profile to the innovator brand (similarity and difference factors were 68 and 7, respectively), and bioavailability and bioequivalence studies showed it was bioequivalent to the innovator product.Conclusion: Product AZI-E was the most promising locally manufactured azithromycin formulation (AZI-E) that has potential to reduce maternal sepsis in Nigeria when compared with the innovator brand.Continuous pharmacovigilance is advocated to safeguard public health.