Profiling of Some Known Anti-Malarial Drugs Using a High Performance Liquid Chromatography (HPLC) Separation/Extraction Technique

WHO estimates that more than 1.5 to 2.0 million deaths attributed to malaria each year occur in African children (WHO, 1996) The development of synthetic anti-malaria drugs forms one of the most interesting chapters in the history of malaria chemotherapy. The major obstacle to successful chemotherapy of malaria has been the development of resistant to anti-malarial drugs. Research into drug monitoring has become an increasingly practical preposition (Ayitey-Smith, 1988) This study has been planned in order to develop a reliable technique of xtraction/separation methods for some known antimalarial drugs from blood plasma. For purity sake, only five pure antimalarials have been secured to prepare the serial standards as well as to spike the plasma to be used. These drugs are chloroquine, fansidar, quinine, amodiaquine and pyrimethamine. Specified amount of each antimalarial drug was used to spike the plasma and aqueous samples. The aqueous was used as control hence both the plasma and the aqueous underwent the same treatment. Extraction was performed on the spiked samples and the extracts were analyzed by HPLC.Recovery was calculated from the results of all the extracts. Since the recovery only could not give the extent or the degree of the extraction one-way ANOVA with Tukey‟s multiple comparison test was also performed. The extractability of chloroquine, amodiaquine and fansidar were effective for both the control and the plasma. The extraction methods for quinine and pyrimethamine were not very effective. ANOVA and Tukey‟s multiple comparison test of chloroquine produced p < 0.0456 (*) and p<0.014 (**) meaning extraction was very effective. However it was clear that at lower concentration, extraction was poor. The method is therefore recommended. The ANOVA and Tukey‟s test on the mean recoveries for fansidar gave p values of < 0.0046 (*) and p < 0.0016 (**) for peak height and peak area respectively. These values showed that the iii extraction was effective and on the other hand fairly effective under the peak height and peak area respectively. In summary, one could say that the extraction of fansidar was effective under peak height; thus this method of extraction is recommended. For Quinine, Tukey‟s test and ANOVA of the mean recoveries indicated poor results; p < 0.0001 (***). Though the mean recovery (%) for both peak height and peak area looked good, the method of extraction needs to be improved. ANOVA and Tukey‟s test performed on mean recoveries for amodiaquine gave p < 0.046 (*) and p < 0.002 (**) for peak height and peak area respectively. This showed that the extraction was effective under peak height fairly effective under peak area. These results indicated that the extraction was effective. The method is therefore recommended. When the mean recoveries for pyrimethamine extracts was subjected to ANVOVA and Tukey‟s multiple comparison test, p < 0.0001 was produced for both peak area and peak height. This showed that there was an extremely significant difference hence the extraction was not effective. The method is therefore needs to be improved. In addition to the above extracts, extractions were performed on double blind test samples, and three (3) samples of volunteers. The blind test was carried out on twenty two (22) pregnant women who were given chloroquine, fansidar and placebo at random. For the volunteers, the first took chloroquine, the second Fansidar and the third took amodiaquine. Blood samples were taken from the women and the volunteers. Extraction was then performed on the plasma of these samples. HPLC analysis on these extracts was able to identify the double blind test samples. Volunteers‟ samples were run alongside the spiked control and plasma samples. Using the retention time of the standard antimalarial drugs, six (6) of the blind test samples, proved to be chloroquine and ten (10) as fansidar. Four (4) of the samples results did not show any appreciable peak near the retention time of neither chloroquine nor fansidar. Hence they were classified as placebo and two contaminations were observed. iv In conclusion, the extraction methods for Chloroquine, Amodiaquine and Fansidar were effective. But the extraction techniques for Quinine and Pyrimethamine were not effrctive hence, further work needs to be done on them.

Source: KNUST