Quality assessment of three imidazole antiparasitics (albendazole, mebendazole and metronidazole) sold in Benin

Illicit circuit of medicines disrupts the quality assurance system and the rational use of medicines. Substandard and falsified (SF) medicines present a major risk for the public health, due to lack of active ingredient and/or toxicity of certain components. The purpose of this study was to evaluate the quality of three imidazole antiparasitic medicines (albendazole, mebendazole and metronidazole tablets) sold in Benin, to describe the different forms of non-compliances of the medicines sold in the illicit circuit. The samples were collected in the
formal and illicit (informal) circuits. The results appeared as follows: irregularities of packaging (25.5% of samples from the illicit circuit); mass uniformity test (14.7% of samples from the illicit circuit were noncompliant); disintegration test (2.1% of samples from the illicit circuit and 3.5% from the formal circuit were non-compliant); identification (all samples were compliant) and assay (47.1% of samples from the informal circuit were non-compliant among which 26.5% of under-dosing and 20.6% of overdose). In sum, there were respectively 38.3% (i.e. 18/47) and 3.5% (i.e. 2/58) of non–compliance in the illicit and formal circuits