Assessment of impurities in pharmaceutical solid dosage forms using Thin Layer Chromatography (TLC)

Abstract

Evaluation and monitoring of likely chemical impurities in products could assist in minimizing risk to patient and therefore enhance safety of medicines. The objective of this present research was to assess the quality of glibenclamide and paracetamol tablets using visual inspection format of the Global Pharma Health Fund (GPHF) and Thin Layer Chromatography (TLC), and to, where possible, detect and identify the impurities present using retention factor (Rf) values of TLC. Glibenclamide and paracetamol tablets were chosen because of their public health interest of the former being widely prescribed and used for prolonged period of time and the later being commonly used as over-thecounter medication. Various brands of both tablets sold in pharmacy retail shops in Jos metropolis were obtained. Visual inspection and TLC analysis of all brands for product integrity and detection and identification of possible impurities respectively were carried out. Results show that some brands of glibenclamide and paracetamol tablets did not follow regulatory requirement for proper labeling because some vital information such as batch number, manufacturing and expiry dates were missing from the primary package. The result of TLC analysis showed that there was no impurity isolated in any sample of glibenclamide tablet. On the other hand, over 45 % of paracetamol samples analyzed showed presence of aniline.

Keywords: Impurities, TLC, Safety, Paracetamol, Glibenclamide, Regulation