Construction and in vitro/in vivo evaluation of menantine hydrochloride oral liquid sustained-release drug delivery system.

OBJECTIVE: The purpose of the present study was to formulate a menantine hydrochloride (MH) sustained-release suspension. METHODS: Menantine hydrochloride drug resin complex (MH-DRC) was prepared with strong acid cation exchange resin as carrier using water bath method. The MH-DRC was characterized using scanning electron microscopy, X-ray diffraction and infrared spectroscopy. The MH-coated microcapsule (MH-CM) with optimized formulation was further dispersed in a suitable medium to obtain a sustained-release suspension. The rats were given both the MH sustained-release suspension and the commercial MH sustained-release capsule by intragastric administration. The plasma concentration-time curves and related pharmacokinetic parameters were also investigated using a non-atrioventricular model. RESULTS: MH and ion-exchange resin were ionically bonded. AmberliteIRP®69 had a higher affinity for MH at the initial concentration of 5 mg·mL-1 and a reaction temperature of 25.0 ± 0.5 °C. In vitro drug release profile showed that both the drug resin complex and the coated microcapsules had a certain level of sustained-release effect. The t1/2 of MH sustained-release suspension was extended from 68.44 h to 72.79 h with the peak blood concentration being decreased to 3.56 µg·mL-1 and the Tmax extended to 12 h compared with the commercial MH sustained-release capsule. The concentration-time curve of the self-made MH sustained-release suspension was flattened and the average relative bioavailability (Fr) was 116.65% compared with the commercial MH sustained-release capsules. CONCLUSIONS: The findings showed that the MH sustained-release suspension was successfully formulated with acceptable pharmacokinetic indices for effective treatment of Alzheimer's disease.

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.