EVALUATION OF COMPARATIVE BIOAVAILABILITY AND BIOEQUIVALENCE ANALYSIS OF TERAZOSIN HYDROCHLORIDE

TERAZOSIN HYDROCHLORIDE

Abstract

Terazosin hydrochloride is a selective α₁-adrenergic receptor antagonist used to treat high blood pressure and benign prostatic hyperplasia. Due to interest by patients, prescribers, and payers for cost-effective and therapeutically equivalent generic formulations, the evaluation of bioavailability and Bioequivalence (BE) has been a significant focus area for regulatory authorities and pharmaceutical companies. Regulatory authorities, including the United States Food and Drug Administration (FDA) and the European Medicines Agency (EMA) have established guidelines related to the requirements for BE studies, as well as requiring the use of validated bioanalytical methods to quantify drug concentrations in biological matrices. BE studies focus on pharmacokinetic parameters such as the maximum plasma concentration (Cmax), time to Cmax (Tmax), and area under the curve (AUC) from the plasma concentration vs. time curve, which gives an estimate of the rate and extent of drug absorption. This article discusses current regulatory frameworks and important considerations in the design and conduct of BE studies recently provided by the FDA and EMA (e.g., validated bioanalytical methods and pharmacokinetic parameters such as Tmax, Cmax and AUC). The extent to which the industry adheres to BE study design and conduct regulations, as well as the issues around studying population, dosage form and statistical analysis of the results, will also be explored. Discussion will also include potential biowaivers for BCS Class I and III drugs, which are important for development, and still maintaining safe therapeutic equivalence. The alignment of regulatory requirements and scientific advancement permits navigation through the safe and effective development and marketing of generic terazosin hydrochloride products.