Tudy On In Vitro Release Character And In Vivo Behavior Of Harmine Gelatin Microspheres

Study on in vitro release character and in vivo behavior of harmine gelatin microspheresObject To research the in vitro release character of HM-GMS primarily and to evaluate the bioavailability of the preparation with in vitro dissolution rate combining pharmacokinetic results. Methods Three dissolution measures were compared in order to stimulate the state in vivo more actually.The influnces of the release mediums,their pH and flow rate were investigated respectively.Proper dynamic model was used to describe the release character. Hepatic arterial embolization was carried out on rabbits and dogs for studying the behavior in vivo.The correlation test had been done between accumulate release percent and absorption coefficient in vivo. Results Continous flowing method was chosen to study the release character of the HM-GMS.The results showed that drug release speed was much faster in water than in other release mediums.The release rate showed no distinctive difference when the pH of phosphate buffer increased. Flow rate had the effect on the drug release.Release profile in vitro can be described by the two-phase dynamic model. Stastistical treatment of pharmacokinetical meters showed great difference inα1/2 ,β1/2 ,Cl ,AUC and MRT between microsphere group and solution group in dogs as well as in rabbits.A significant line correlation exsited between the dissolution rate and absorption coefficient in vivo for the microspheres in dogs(p<0.01 )and rabbits(p<0.05). Conclusion HM-GMS has the property of sustained release. The dissolution rate can be regarded as a reference to evaluate the absorption of microspheres in vivo.