Two pH sensitive polymers (Eudragit L30 D55 and L100) were used as coating materials, respectively, for promethazine hydrochloride and chloroquine phosphate granules formulated with sodium carboxylmethylcellulose and Carbopol 940, respectively, in the ratios 1:1, 1:2, 1:3, and 1:4 (drug:polymer). The granules were characterized. Release studies for the uncoated and coated particles were studied in simulated gastric fluid and simulated intestinal fluid. Result obtained showed that 1:1 and 1:2 ratios of both coated and uncoated granules of the two drugs had short release times and could be recommended for rapid action, whereas 1:4 ratio with low release time could be used for sustained effect. The two granules could be used at varying ratios to obtain desired release characteristics, such that therapeutic concentrations of the two drugs could be achieved.
Systematic Delivery of Chloroquine and Promethazine Using pH-Sensitive Polymers. Available from: https://www.researchgate.net/publication/7912922_Systematic_Delivery_of_Chloroquine_and_Promethazine_Using_pH-Sensitive_Polymers [accessed Dec 28, 2015].