Comparative pharmaceutical equivalence studies of Sofosbuvir 400 mg tablets available in pakistani market

Sofosbuvir is an antiviral drug, which is most commonly being used in Pakistan for the treatment of chronic hepatitis C genotype 1, 2,3,4,5 and 6. Product quality is one of the key indicators for the selection of a safe, effective and economic brand of the same generic. Therefore, a quality control assessment and cost effective comparative pharmaceutical equivalence study was conducted on 3 available brands of Sofosbuvir 400 mg tablets. The price of the brand P-1, P-2 and P-3 were 328.88, 48.47, and 46.74 $ per pack, respectively and were purchased from retail pharmacies of Pakistan. The innovator brand P-1 was considered as reference because of its great physicochemical and quality controlled characteristics. Both the official and non-official tests were applied for the evaluation of physical tests such as hardness, thickness, weight variation, friability and chemical tests like disintegration time, multiple point dissolution profile and assay using already developed HPLC method. Multiple point dissolution studies were carried out at different pH and the data were analyzed for drug release kinetics. Model dependent approaches such as zero order, first order and Hixson-Crowell and model independent approach like similarity factor f ₂ were applied. The results showed that the amount of sofosbuvir in brand P-1 and P-2 was within the USP specification of not less than 80% at 15 min whereas, brand P-3 fell out the limit. Similarly, the value of f ₂ showed that Brand P-2 was found to be similar with standard (innovator) while P-3 was dissimilar. On the basis of outcomes of this study, it will be very useful for the physicians, pharmacists and patients to select the most appropriate quality brand for the treatment of hepatitis C.