Selection of different factors for the Calculation of Similarity factor (f2) and Dissimilarity factor (f1) as per different countries' regulatory recommendations for the biowaiver Study: A Systematic Review

Biowaiver refers to the waiving of bioequivalence studies or in vivo bioavailability. The model-independent similarity factor approach for the dissolution profiling test is considered in the comparison shown in this article survey. Rather than conducting costly and tedious bioequivalence (in vivo) examinations, a dissolution test can be used as an alternative for comparing whether two drug products are identical or not. The purpose of this review is to feature the expectations of various regulatory bodies for biowaiver studies. Initially, no regulatory agency defined the early time point; however, the FDA recently defined the early time point as up to 10 minutes for products with a fast or immediate release rate. The biowaiver approach based on the BCS (Biopharmaceutical Classification System) is intended to reduce the requirement for studies of bioequivalence, so it can provide an alternative to bioequivalence studies. Bioequivalence studies might be waived if in vivo execution can be legitimated by satisfactory dissolution profiling information. The Biopharmaceutical Classification System approach is logical in view of the gastrointestinal permeability, aqueous solubility, and characteristics of the drug molecules. The model-independent similarity factor (f2) method is suggested by numerous regulatory bodies to show dissolution closeness or similarity worldwide. This f2 method is leaned toward on the grounds that it is generally simple to utilize, the similarity factor (f2) value is not difficult to calculate, and a well-known acceptance criteria for profile closeness or f2 (similarity) (i.e., f2≥50) has been set. As per comparison with different regulatory guidelines for dissolution profiling, it was found that there were many divergences in the criteria for exemption from the F2 criteria, the selection of the minimum number of dissolution profile time points, the selection of end time points, and the coefficient of variation. So it is needed to harmonies a guideline on biowaiver studies that can be applicable to all countries for ANDA (Abbreviated New Drug Application) filing purposes.