Preparation, characterization of clonidine hydrochloride resinates and investigation of the kinetics and thermodynamics of the ion exchange process.

Clonidine Hydrochloride (CH) resinates were prepared by plating solution with strong acid cationic-exchange resin as the carrier. The drug resinate's combination mode was characterized by SEM, DSC and X-ray diffraction. The reaction at different temperatures and the influence of different ion exchange resins on the ion exchange process were studied, The kinetics and thermodynamics of ion exchange resins under different temperatures were studied. The In vitro drug liberate from the drug-resinates was investigated in different mediums. The study proved that the combination of CH and resin was not a simple physical mixture but ionic bonded. With the increase of temperature and ion exchange and Amberlite⌖IRP69 had a higher affinity for ionic drugs. The results of In vitro release experiment showed that temperature, medium volume, stirring speed, the ionic strength and type. The In vitro release of CH resin was fitted with Viswanathan equation, it conformed to the process of particle diffusion. Also, the results showed that further coating of CH resin is necessary to achieve a significant continued release effect.