EFFECT OF PROCESS VARIABLES ON COMPLEXATION OF BITTER DRUG USING ION EXCHANGE RESINS

Donepezil Hydrochloride is a reversible inhibitor of the enzyme acetyl cholinesterase and used as an Alzheimer's disease, but due to bitterness it has poor patient compliance. Strong and weak cation-exchange resins were used to block the functional group responsible for causing bitter taste by forming resinates of drug. An attempt was made to form drug-resin complexes of different ratios with various cation exchange resins like Indion-234, Indion-234, and Indion 254. Effect of variables was studied on percentage complexation of drug like type of process, time of complexation, time of swelling, temperature, activation media, pH, and concentration of loading solution and mode of complexation. Drug-resin complexes were characterized by DSC and FTIR study. Resinates of different ratios were subjected to sensory evaluation for taste by ranking method. Release of drug from each complex was studied at the pH of saliva (6.8) and at the gastric pH (1.2) to determine amount of the drug that would be released during the administration of formulation. Stability of drug-resin complexes was studied by carrying out AST at elevated temperatures. Amount of drug released from complex was about 5% at salivary pH and 95% at gastric pH.Drug: Indion-234 (1:3 w/w) complex showed good complexation. Drug-resin complex shows negligible decomplexation of resinate at salivary pH and maximum at gastric pH. Keywords: Taste Masking, IER, Drug-Resin Complex, SSF, SGF.