Study On TX Freeze-dried Liposomes

TX is widely used in the treatment of pneumonia, asthma and seizures,but its physical and chemical properties also determines that it is insoluble in water, poor oral absorption and poor absolute bioavailability characteristics, to some extent,which limit TX play a therapeutic role.Considering the above situation and the convenience for clinical application, we sought to develop a good stability liposome of TX, where we investigated systematically and compared to those liposomes.In this experiment, the encapsulation efficiency and particle size as indicators of different membrane preparation of TX liposome were compared to determine the best Prescription process, taking into account the TX nature and needs of the industrial production, the use of ethanol injection was prepared by TX liposome.Soybean lecithin was used as the carrier while poloxamer-188was used as surfactant during the formulation design and preparation techniques of TX liposomes. Ultimately,using the single factor investigation,we obtained the optimization prescription that composed of0.4%(w/v) TX,1:3(w/w) ratio of drug to lipid,1.5%(w/v) poloxamer-188,0.1%(w/v) soybean oil,phosphate buffer solution(pH7.6). The mean particle size of TX liposome was250nm, the encapsulation efficiency was exceed95%.Due to the presence of liquid, Common liposomes prone to particle aggregation sedimentation phospholipid oxidation and decomposition, encapsulating drug leakage and other problems, resulting in unstable liposomes.Therefore, we used freeze-drying method developed the TX lyophilized liposomes, can improve the stability, prolonged storage period.However, freeze-drying technology may cause severe and irreversible destruction,so the freeze-dried conditions and protective agent for freeze-dried is crucial to be studied.Screening of the protective agent for freeze-dried, ultimately,5%glycine and5%sodium chloride as a protective agent in the freeze-drying process.Inspecting the physicochemical properties and stability of TX liposomes and freeze-dried powder, take appearance and color, particle size and encapsulation efficiency as indicators, its physical and chemical stability are good.We also investigated the stability of the three block medium amplified preparation, including the test of influencing factors (illumination, high temperature and high moisture). The results of stressing showed the TX liposomes are unstable under illumination and high moisture. So we should keep the TX liposomes avoiding light and dry-storage.