Adsorption-desorption of ondansetron on latex particles

Ondansetron is a carbazol with antiemetic properties. It is used primarily to control nausea and vomiting caused by cytotoxic chemotherapy and radiotherapy, as well as for treatment of postoperative vomiting in gynecological surgery. Ondansetron has a shelf life of about 3 hr; hence, it is a matter of great interest to determine the ideal adsorption-desorption conditions for this drug on latex particles for designs of formulations (oral suspensions) containing polymers with the aim of delivering different drugs in a prolonged and controlled fashion. Time, pH, electrolytes, and concentration of the active principal at which maximal adsorption occurred were determined. Desorption of the drug from latex polymer particles was studied in different media. The results obtained suggest that this polymer is suitable as carrier of drug for obtained formulations of controlled release. The findings suggest that pH is the principal factor influencing the release of the ondansetron from Aquateric®. The greatest release of drug occurs at acid pH, approximately 70% in the first hour; for the basic medium, the release is about 6%