Are counterfeit or substandard anti-infective products the cause of treatment failure in Papua New Guinea?

Counterfeit and substandard products present a big challenge to any national plan or policy devised to improve public health. Poor quality drug products are especially a problem in lower income countries where product information and drug regulation enforcement are scant or absent. The primary aim of the present study was to evaluate the quality of amodiaquine and amoxicillin formulations sold in Papua New Guinea (PNG) and to detect the presence of counterfeit or substandard drugs in circulation, if any. Fourteen samples, collected from five registered pharmacies in Port Moresby, PNG, were subjected to visual inspection, quality control tests, and verification of product authenticity. The quality control tests included weight variation, content uniformity, thin layer chromatography, and dissolution. None of the products complied with all of the evaluation criteria. Two products, one of which was purportedly distributed by a company which proved to be nonexistent, contained no detectable amodiaquine. The present study confirms that counterfeit and substandard amodiaquine and amoxicillin products are finding their way into the distribution chain in Port Moresby, PNG. This quality problem with anti-infective products is of great concern, as it not only exposes patients to poor quality products but also fosters the development of resistant bacterial strains.