Comprehensive Characterisation of the Innovator Product: Targeting Bioequivalent Generics

Generic products are cost effective and speedy surrogates for high-priced innovator/branded products. The prerequisite for the development of a generic product is therapeutic equivalence (comprising pharmaceutical equivalence and bioequivalence) to the innovator product, thus ensuring comparable efficacy and safety profile. The probability of successfully developing a bioequivalent product can be improved by developing a formulation equivalent to the reference listed drug (RLD), in terms of the quantitative, solid-state characteristics of the active pharmaceutical ingredient (API) and the manufacturing process. This can be achieved by a systematic and thorough characterisation of the RLD. The present study was aimed at developing a methodology for characterisation of ranitidine hydrochloride tablets, with special emphasis on the solid-state characterisation of the API in the tablet. A differential solubility method was employed for the separation and quantification of excipients present in the tablet. Solid-state properties were characterised using a range of microscopic, thermal, spectroscopic and crystallographic techniques. In addition, results were confirmed by preparing inhouse tablets of the polymorphic forms I and II, using the decoded quantitative formula.