Determination of in-vitro Equivalence of Paracetamol Tablets

Bioequivalence studies are the usually accepted method to determine the therapeutic equivalence of two drugproducts. Because in-vivo bioequivalence studies are time consuming and expensive to conduct, majorregulatory authorities have introduced biowaivers for some selected medicines belonging to BCS class 1 andIII drugs. Comparative dissolution tests are used in biowaiver procedure to waiver the bioequivalencerequirement. We performed this study to see whether two brands of paracetamol tablets are bioequivalentusing the in-vitro methodology. In the first stage of this research study, British Pharmacopeia 2012 qualitytests were performed on the two selected paracetamol tablet products to determine whether they arepharmaceutically equivalent. In the second stage in-vitro equivalence of the two products was determinedusing the biowaiver testing procedure given by the World Health Organization. Dissolution profiles weregenerated at pH values, 1.2, 4.5 and 6.8. Results were compared through two model independent methods,difference factor (f1) and similarity factor (f2). The two paracetamol tablet products tested, complied with allthe quality requirements of the British Pharmacopeia 2012. For the two products, the difference factor (f1)was below the 15 and similarity factor (f2) was above the 50 in all dissolution test conditions. These resultsconfirm that the two products are pharmaceutically equivalent. The test product is also bioequivalent to thereference product in-vitro, and therefore they can be interchangeable during clinical use. This study showsthat in-vivo bioequivalence testing can be waived using the in-vitro method, for some pharmaceuticalproducts such as paracetamol tablets.KEYWORDS: Paracetamol tablets, Biowaivers, Dissolution profile