Development and validation of in vitro release test for a BCS class 4 drug nepafenac ophthalmic suspension using USP apparatus IV

The objective of the present study was to develop and validate an in vitro release test for Nepafenac ophthalmic suspension using a USP Type IV apparatus. Nepafenac is an approved drug for treating postoperative ocular inflammation and pain following cataract surgery. Various conditions, including the type and volume of dissolution medium, filter type, sample weight, and flow rate, were evaluated. The optimal in vitro dissolution profile was achieved using Apparatus IV (open-loop), STF (pH 7.4) as the dissolution medium, a GF/D membrane filter, and 0.5 g of the sample with a medium flow rate of 10 mL/min. Drug release was assessed using a high-performance liquid chromatography (HPLC) method developed for this study. The in vitro release method was validated according to current ICH and FDA guidelines, considering parameters such as specificity, accuracy, precision, and stability of the analytical solution. The results were found to be within the acceptable criteria. Given the high costs associated with preclinical and clinical trials, implementing a reliable in vitro release method could provide valuable insights into the product's performance before conducting expensive in vivo bioavailability studies.