Post-market surveillance of albendazole tablet brands in Kenya: Implications for deworming programs and clinical outcomes

BACKGROUND: Albendazole is a broad-spectrum anthelminthic extensively used in clinical settings and national deworming programs. It is the cornerstone of the preventive chemotherapy for soil-transmitted helminthiases prevalent in low-resource settings. The high proliferation of albendazole generic products, with poor post-market surveillance capacity in the low- and middle-income countries, poses dire risk of substandard and falsified medicines, which may predispose patients to treatment failures, adverse drug reactions, morbidity, and mortality, with consequent loss of public confidence in healthcare systems. OBJECTIVE: This study aimed to determine the quality and pharmaceutical equivalence of albendazole 400 mg tablet brands marketed in Nairobi, Kenya. EXPERIMENTAL: A cross-sectional analytical study was conducted on seven albendazole 400 mg tablet brands purchased from pharmacy outlets in Nairobi. Tests for identity, friability, hardness, disintegration, assay, uniformity of weight, and dissolution were conducted as specified in the United States, British and International Pharmacopoeias. Dissolution profiles of generic albendazole tablet brands and the innovator brand (Zentel) were compared using model independent fit factors f1 and f2, and the dissolution efficiency (DE). Data was captured and analyzed using Microsoft Excel 2021, and reported as means, relative standard deviations, and percentages. RESULTS: All the seven albendazole 400 mg tablet brands complied with compendial specifications for identity, friability, hardness, assay, and uniformity of weight. However, two brands (EK5 and EK6) did not comply with the disintegration test and consequently demonstrated extremely poor dissolution, having released <6% of labelled albendazole content at 60 minutes with DE < 5%. Only two brands (EK4 and EK2) exhibited dissolution profiles that approximated the innovator brand (f2 > 50, f1 < 10) and could be used interchangeably, while the other two (EK3 and EK7) had intermediate drug release. CONCLUSION: While all tested albendazole 400 mg tablet brands complied with basic pharmacopoeial specifications for quality, dissolution testing revealed significant nonequivalence, with only three (42.86%) of the seven brands being pharmaceutically equivalent. Poor dissolution of majority (57.14%) of albendazole tablet brands portends therapeutic insufficiency and development of drug resistance, reinforcing the need for stringent post-market surveillance to safeguard public health.