Comparative in vitro and in vivo study of a sugar-coated chloroquine preparation marketed in Tanzania versus an ordinary brand

Objective: To investigate the absorption and the quality of a sugar-coated chloroquine (CQ) marketed in Tanzania. Method: Twenty healthy volunteers were randomised to take either the test b rand (group A) or a control chloroquine phosphate (group B). Each subject r eceived 300 mg chloroquine base. Whole blood dried on filter papers were co llected at time 0 and at 15 and 30 min and at 1, 2, 3, 4, 6, 8, 24, 36, 48, 72 and 168 h after drug intake. Urine samples were collected at time 0, 0- 4 h, 4-8 h, 8-24 h, 24-48 h and 48-72 h after drug administration. In an in vitro study, six tablets from each of the two CQ preparations were checked for the amount of active drug contained in each tablet and their dissoluti on rates. Results: The blood concentration Area Under the Curve (AUC) of group B was about 10% larger than that of group A. The total amounts of CQ plus deethyl chloroquine excreted with the urine during the 72-h study period were 5% fo r group A and 6% for group B. None of the pharmacokinetic parameters were s ignificantly different between the two groups. All the tablets contained th e labelled amount of chloroquine; however, one tablet from the test drug fa iled to fulfil the required dissolution rate. Conclusion: We found no major difference between the AUCs of the two CQ pre parations, but the sugar-coated brand has shown to have variable dissolutio n rate.