Study On Two Kinds Of Thymopentin Preparations

The pentapeptide Thymopentin (TP-5) is the fragment of thymopoietinⅡ(32-36) with basic sequence H-Arg-Lys-Asp-Val-Tyr-OH. It has the same biological activity as the thymopoietin II, which has the double-direction immunities to our bodies. Thymopentin can promote or suppress immune functions, which tend to normal. A multitude of studies have shown the efficacy of TP-5 treatment for the therapy of a variety of diseases, including primary and secondary immune deficiencies, autoimmunity, infections, cancer, hepatitis and AIDS. The pharmaceutical products of thymopentin are mainly injections at present. Frequent injections for long time impared the compliance of the patients and therapeutical efficacy,which Frequent injections cannot satisfy clinical to the TP-5 peptide application demands either.Therefore, based on the investigation of thymopetidum for Injection, this article prepares thymopentin-loaded enteric microspheres, and explores its performance and drug's effects.Our work includes three parts:1. Preparation of thymopetidum for InjectionSeveral kinds of parameter were chosen to prepare lyophilized injection of thymopetidum Sodium such as pH, solvent and excipient according to the characters and quantification. One blokes of freeze-dried Thymopetidum Sodium injection was produced. We performed the quality analysis to the preparation. Also we made a conclusion that all items had measured up the demand.After storaged at 25℃and 40℃for 6 months, the stability of the preparation was evaluated from six aspects which are the appearance, pH, clarity and color of solution, particulate matter, quantification and related substance of preparations. Conclusions showed the stability of Thymopetidum Sodium is good and the technics is reasonable.2. Preparation of thymopentin-loaded enteric microspheres TP-5 was encapsulated within enteric microspheres of Eudragit L100 by oil in oil (o/o) emulsion solvent evaporation method. The process variables included emulsifier type and concentration, the time of volatile solvent, the volume ratio of organic solvent to water, the concentration of the Eudragit L100, the initial amount of drug, on drug encapsulation efficiency, grain diameter and skip distance, and in vitro release profiles were investigated.3. Pharmacodynamical study on thymopentin-loaded enteric microspheresIn vivo studies are undergoing to evaluate the bioactivity of the entrapped thymopentin. The immunodeficient BALB/c mices model was prepared by hydrocortisone and then thymopentin-loaded micorspheres were fed orally, the group of thymopentin injected to the model mice being as positive controls. The bioactivity of thymopentin were determined by experiments of E-rosette formation rate. The results showed that thymopentin containing enteric micorspheres could enhance the E-rosette formation rate of lymphocyte of immunosuppressed mice induced by hydrocortisone and the E-rosette formation rate of lymphocyte were correlated with the thymopentin dose.