PurposeInvitro release testing (IVRT) is an essential analytical method used to assess the bioequivalence of semi-solid dosage forms, including topical creams, ointments, and gels. Accurate IVRT is critical to ensure that these products perform as intended under physiological conditions. The development of IVRT methods requires careful consideration of several factors, including the choice of the release medium, establishment of sink conditions, selection of diffusion membranes, and determination of appropriate sampling time intervals. These factors are crucial for ensuring that the test conditions closely mimic the physiological environment and reflect the intended clinical use of the product. Proper selection and optimization of these parameters are vital for achieving reliable and reproducible results.MethodsThis review briefly presents the standards for the development of bio-relevant methods and validation of in vitro release testing for regenerative topical formulations.ResultsThese guidelines highlight the significance of evaluating the physicochemical properties of the semisolid dosage form, including viscosity, pH, and drug solubility, in optimizing IVRT methods. Additionally, this document provides a structured approach for conducting IVRT experiments, including the development of a drug release profile, statistical analysis of the release data, and assessment of variability and reproducibility. Considerations for validating the IVRT method, including process specificity, linearity, precision, and robustness, were also outlined. Furthermore, the guidelines underscore the necessity of conducting IVRT studies under various conditions, such as temperature, humidity, and storage, to account for real-world variations.ConclusionThe importance of documenting all aspects of IVRT method development and validation to ensure traceability and compliance with regulatory standards is emphasized. This comprehensive review provides a systematic approach for method development, validation, and optimization, contributing to the establishment of reliable and bioequivalent IVRT methods that enhance the quality and safety of these pharmaceutical products.Lay SummaryIn the field of pharmaceutical development, particularly for regenerative topical products, IVRT has emerged as a crucial method for evaluating the effectiveness of drug release from its formulation into a biological environment. This test is essential to ensure that topical medications deliver their active ingredients appropriately and safely when applied to the skin. IVRT serves multiple purposes for the development and validation of topical formulations. Despite their importance, there are challenges in standardizing IVRT methods across different formulations. Variability in formulation composition, such as differences in viscosity or solubility, can significantly affect drug release rate. Additionally, advancements in technology may enhance IVRT methodologies, making them more efficient and capable of providing real-time data on drug release profiles. This could lead to improved product formulations and better therapeutic outcomes in patients using topical therapies.
