辣椒碱在不同介质中的平衡溶解度及TPU膜载药性能分析

目的:测定辣椒碱在供热塑性聚氨酯弹性体(TPU)吸载的不同介质中的平衡溶解度,考察不同型号TPU膜的载药性能。方法:采用UV测定辣椒碱在乙醇、甘油、丙二醇和水中的平衡溶解度,考察其在不同温度和pH条件下的平衡溶解度变化。在此基础上,评价不同型号TPU膜在不同介质中的载药行为,并考察温度与溶液pH对膜载药性能的影响。结果:辣椒碱在50%丙二醇中平衡溶解度最大,在水中最小;随着温度的升高,与有机溶剂体积分数的增大,辣椒碱的平衡溶解度均呈现上升趋势。pH变化对辣椒碱在30%乙醇和50%丙二醇中的平衡溶解度有较大影响,而对其他介质中辣椒碱的平衡溶解度影响较小。TPU膜载药性能受溶液种类、温度及p H的影响,溶液中辣椒碱浓度对TPU膜载药能力影响最大。结论:辣椒碱在50%丙二醇溶剂中溶解度最大,其与温度呈正相关,pH会影响辣椒碱在不同溶剂中的溶解度;选择对药物有较大溶解度的溶剂,有助于TPU膜的载药。

Equilibrium Solubility of Capsaicin in Various Menstruums and Drug Loading Property of Thermoplastic Polyurethanes

Objective: To determine equilibrium solubility of capsaicin in different menstruums and investigate drug loading property of thermoplastic polyurethanes (TPU). Method: Excess capsaicin was mixed in pure water, ethanol solution, glycerol solution and propylene glycol solution, respectively, and was shaken for 24 h.UV was employed for determination of capsaicin dissolved in these solvents and the equilibrium solubility was calculated.What''s more, the equilibrium solubility of capsaicin in these tested menstruums under the conditions of different temperatures and pH values was also assayed.After that, drug loading behavior of TPU in various menstruums containing capsaicin with different liquid temperature as well as pH values were evaluated. Result: At room temperature, the largest equilibrium solubility of capsaicin was achieved in 50%propylene glycol solution.As temperature increased, the equilibrium solubility was risen.The acidity of solvent impacted the equilibrium solubility, especially pH value of capsaicin in the high concentration of short-chain alcohols.The drug loading capacity of TPU was effected by the liquid temperature and pH values of the tested menstruums. Conclusion: The 50% propylene glycol solution holds the largest equilibrium solubility of capsaicin, which positively correlates with temperature.In addition, pH values of these tested solvents should be noticed in evaluation of this alkaloid in these tested menstruums.Increasing drug concentration in menstruum will contribute to improve TPU loading with capsaicin.