Quality Control of Paracetamol Drugs in West Africa: Spectrophotometric Analysis of Eight Most Available Commercial Formulations in Niger.

Paracetamol is a popular analgesic and antipyretic drug. The infiltration of counterfeit drugs into the West African medicines market is of concern. The present study aimed to investigate the quality of eight (8) most used paracetamol drugs. A cost effective and reproducible spectrophotometric method was first developed. The absorbance signal was measured at 245 nm (absorption maximum) in the used medium (water-ethanol; v:v, 20:1). A Linear calibration curve (r²=0.999) allowing paracetamol active ingredient analysis in pharmaceuticals was established with a large linear dynamic range (LDR) between 2 -40 μg/mL and a relatively low limit of detection (LOD = 0.65 μg/mL). In eight (8) commercial formulations obtained from licensed (4) and illicit (4) markets, five (5) have substandard concentrations and one (1) is a fake drug. All the formulations obtained from illicit market are of bad quality: three of them have substandard concentrations and the fourth one is a fake. The presence of two (2) substandard drugs among the four (4) samples obtained from formal pharmacies open the debate on the infiltration of the licensed medicines trade by the illicit market products. This is particularly worrying in West African countries devoid of efficacy drug regulatory system and where medicines quality control mechanism is weak.