DEVELOPMENT AND VALIDATION OF A LC-UV METHOD FOR THE DOSAGE OF A TRACER IN AN IMPROVED TRADITIONAL MEDICINE

According to World Health Organisation, 80% of the African populations use Improved Traditional Medicines (ITM) to threat several diseases. Even if some of these ITM are nowadays registered with local health authorities, the knowledge of their qualitative and quantitative composition still remains a challenge for ensuring health security of populations. In this context, an analytical method using liquid chromatography technique with UV detection was developed to allow the dosage of a tracer (major compound) in an ITM (syrup containing extract plants) registered in D.R. Congo by the “Centre de Recherche en Médecine Traditionnelle Améliorée” and marketed for use against malaria. For that purpose, a simple and rapid experimental plan considering a Plackett-Burman design was applied by testing simultaneously two significant factors, temperature of analytical column (T°) and gradient time (TG) for eluting acetonitrile (ACN) from 5% to 95%, while focusing on the separation of the tracer and an adjacent unknown compound (critical peak pairs). Suitable separation (resolution of 1.5) was obtained between these latter with T° of 15°C and TG of 60 min (20% to 65% of ACN). Prior to routine use, the analytical method was validated following the total error strategy described by the SFSTP guidelines and according to the ISO norm 17025:2005. Specificity/selectivity of the method was demonstrated by the absence of interference at the retention time of the major compound comparing to the syrup matrix. Very interesting results were observed for trueness (relative biases below 0.9%), for precision (RSD mostly below 2.2% for repeatability and time-different intermediate precision), for accuracy (beta tolerance intervals below 10% of the acceptance limits) and linearity. Finally, the method was applied to quantify the major compound in several batches of syrups ITM as well as for stability studies.