Abstract :
[en] Poor quality medicines pose a threat to all health systems. It is obvious that they have harmful consequences not only from the point of view of public health, but also from the economic and socio-economic point of view [1]. Over the past 15 years, substandards and falsified drugs have received increasing attention in scientific publications. However, there is little reliable data determining their prevalence with accuracy due to the scarcity of well-designed studies identified as having good methodological quality as well as representative sampling strategy [2-4].
In this context, we have decided to evaluate the prevalence of poor quality anti-infective medicines in two Cameroon areas (Yaoundé and Douala), inspired by the Medicines Quality Assessment Reporting Guidelines (MEDGUARG) [3] and WHO recommendations [4] for the sampling strategy and the methodology.
Our study will focus on the formal private sector. Pharmacies as well as drugs products will be sampled by a stratified random sampling strategy. The study will focus on two anti-infective medicines (ciprofloxacin and metronidazole 500mg tablets) in tablets, from 96 outlets in the cities of Yaoundé and Douala that are the two main cities (Yaoundé and Douala) of Cameroon representing almost 70% of private outlets of the country. Mystery shoppers will collect samples using a specific scenario. As a prelude to our field study, screening and dosage methods have to be developed and validated in Liège University. They se methods consist of vibrational spectroscopy (near infrared and Raman spectroscopy) as first screening techniques and HPLC for identification and assay. For vibrational spectroscopy, qualitative models will be developed for identification using chemometric tools. HPLC methods will be validated following the total error approach using accuracy profile as decision tool. The medicines collected will be first analysed visually (physical appearance tests), then field methods will be implemented (screening methods: Paper Analytical Devices (PADs), handled NIR device). Finally laboratory testing (assay and confirmation methods: HPLC reference method and pharmacotechnical tests) will be performed at LANACOME (Yaoundé, Cameroon). Suspect and unusual samples will be transported to Liège University for further analyses. All these methods will be applied according to a decision tree based on observed facts. The study will be submitted to the ethics committee of the Ministry of Health in Cameroon.
An accurate and fast HPLC method for identification and quantification of both metronidazole and ciprofloxacin has been developed. Identification models for some brands of ciprofloxacin and metronidazole using handled NIR and Raman devices has been developed before implementation on field.
This study will allow us to evaluate not only the prevalence of poor quality anti-infective medicines marketed in Cameroon but also outlets dispensing substandard and falsified medicines. They will be distinguished into sub-standard, degraded or falsified and classified according to their country of origin, manufacturer and city of sampling. The results will be notified to the drug regulatory authority in Cameroon and if poor quality medicines are detected, we will proceed with an alert to the WHO Global Surveillance System.
The estimation of the prevalence of counterfeit and falsified anti-infective medicines would be extrapolated to the entire population and depending on the information obtained, evaluate the patient health risk exposed to substandard and falsified anti-infective medicines and develop capacity-building interventions in the fight against poor quality medicines.
