活性成分为内源性物质的药物（以下简称内源性药物）的生物等效性（BE）研究应克服机体自身内源性水平对药物浓度的影响，获得药物的净效应，进而进行BE评价。研究的设计和开展应围绕内源性水平的获知、控制和校正等3个方面，并结合药物的药动学特征进行。梳理研究设计和实施、BE评价以及生物样品分析等方面的技术要点和难点，同时结合氯化钾缓释片、左甲状腺素钠片等典型内源性药物案例对上述技术要点进一步阐释。国内发布的内源性药物的指导原则较少，阐述内源性药物生物等效性研究工作中的特殊性，总结其中的技术要点和挑战，期望对此类药物的BE研究提供一定参考。

The bioequivalence study of drugs with endogenous substances as active ingredients (endogenous drugs) should minimize the influence of the endogenous substance on drug concentration, obtain the net effect of drugs and evaluate the bioequivalence. The study should design and carry out according to the pharmacokinetic characteristics of the drug, and focus on obtaining, control, and correction of endogenous levels. This article summarizes the difficulties and technical points in research design, bioequivalence evaluation, and biological samples analysis. Typical cases such as Potassium Chloride Sustained-release tablets and Levothyroxine Sodium tablets are described to further explain. There are relatively few domestic guidelines released for endogenous drugs. This article describes the unique aspects in endogenous drug bioequivalence research, summarizes the key points and technical challenges, in anticipation to provide reference for the bioequivalence research of endogenous drugs.

R969.1