Study On An Point-Injection Implantion In-Situ Gel

The acupuncture catgut embedding therapy as an important branch of acupuncture science is widely used in clinic for digestive, respiratory and nervous system diseases. At present, the most widely used implanted materials to catgut embedding therapy is catgut. The catgut be main to used for surgery sutured., and it can't complete satisfy clinical request for acupuncture embedding therapy, such as the poor absorbability, tissue reaction, infection. In addition, it is difficult to control the stimulation intensity and the absorbed velocity of catgut in vivo. Therefore, it is of extreme importance to search for a new implanted material that could be controlled and biodegraded.In this paper, we attempt to develop an acupoint implanted in situ gel as a substitute of catgut. Poly(lactic-co-glycolic acid)(PLGA) is adopted as the main drug sustained-releasing materials in the present research. Ephedrine Hydrochloride was chosen as model drugs. Firstly, the in situ gel's solvent and plasticizer are deterimined by measured the solubility of PLGA in various solvents. High performance liquid chromatography (HPLC) method was developed for in vitro assay of drug content and the release rate of drug in Ephedrine Hydrochloride in situ gel. The effects of the type of PLGA on the drug release was studied. Then the effects of the concentration of PLGA and PEG400 in forming of in situ gel was studied. The prescription was optimized by uniform design. An acupoint implanted in situ gel containing 3%Ephedrine Hydrochloride from which drugs can release for 20 days was made. The effects of drug contents, dissolution modium and shaking speed on drug release in vitro were studied. The release test disclosed that the release of drug from the formulation belonged to Fickion diffusion.It has few reports about development of an acupoint implanted in situ gel in China. So it is a original study. The research results show that it is a good foundation of looking for implanted materials instead of catgut acupuncture catgut embedding therapy.