Abstract:
Bioequivalence studies are the usually accepted method to determine the therapeutic equivalence of two drug
products. Because in-vivo bioequivalence studies are time consuming and expensive to conduct, major
regulatory authorities have introduced biowaivers for some selected medicines belonging to BCS class 1 and
III drugs. Comparative dissolution tests are used in biowaiver procedure to waiver the bioequivalence
requirement. We performed this study to see whether two brands of paracetamol tablets are bioequivalent
using the in-vitro methodology. In the first stage of this research study, British Pharmacopeia 2012 quality
tests were performed on the two selected paracetamol tablet products to determine whether they are
pharmaceutically equivalent. In the second stage in-vitro equivalence of the two products was determined
using the biowaiver testing procedure given by the World Health Organization. Dissolution profiles were
generated 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 all
the 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 results
confirm that the two products are pharmaceutically equivalent. The test product is also bioequivalent to the
reference product in-vitro, and therefore they can be interchangeable during clinical use. This study shows
that in-vivo bioequivalence testing can be waived using the in-vitro method, for some pharmaceutical
products such as paracetamol tablets.
