Possibility of extending biopharmaceutics classification system based biowaiver to BCS class IIa drug

Biowaiver studies have been performed to assess the bioequivalence of two drug products. Ibuprofen is a Biopharmaceutics Classification System (BCS) class IIa drug (Low solubility - High permeability) used as analgesic, antipyretic and anti-inflammatory agent. World Health Organization (WHO) placed ibuprofen in the category of biowaiver drugs but Food and drug authority (FDA) and International Council for Harmonization (ICH) has not issued yet any guidelines regarding the biowaiver of BCS class II drugs. Present study was aimed to formulate immediate release (IR) Ibuprofen 600 mg tablets with variable disintegrants. All trial film coated formulations were evaluated physicochemically with in-vitro bioequivalence studies in three buffer mediums (pH 6.8, pH 4.5 and pH 1.2). Samples were analyzed spectrophotometrically at 221 nm and model independent approaches (dissimilarity (f1), similarity (f₂;) and Boot strap) was applied to assess the observed similarity. The similarity factor (f₂;) was achieved only in pH 1.2 in three trial formulations and met acceptance criteria (f₂; 50-100) although the amount of drug release was negligible. This investigation revealed that for BCS class IIa drug (ibuprofen), subsequent analysis of excipients used, pKa of drug and method of manufacturing should also be considered to ensure bioequivalence for a successful biowaiver study.