In vitro release of levonorgestrel from phase sensitive and thermosensitive smart polymer delivery systems.
In vitro release of levonorgestrel from phase sensitive and thermosensitive smart polymer delivery systems.
复制标题
从相敏和热敏智能聚合物递送系统体外释放左炔诺孕酮。
DOI：
10.1081/pdt-54479
复制
发表时间：
2005
影响因子：
3.4
通讯作者：
Singh,Jagdish
中科院分区：
文献类型：
--
作者：
Chen,Sibao;Singh,Jagdish
本研究的目的是开发避孕激素，左炔诺孕酮（LNG），使用相敏和热敏聚合物的注射控制输送系统。将聚乳酸（PLA）与苯甲酸苄酯（BB）和苯甲醇（BA）的溶剂混合物组合用于相敏聚合物递送系统。评价了溶剂系统和聚合物浓度对体外LNG释放的影响。在热敏聚合物递送系统的情况下，使用具有不同丙交酯/乙交酯比率（LA/GA，2.0 - 3.5）的一系列低分子量聚（丙交酯-共-乙交酯）-聚（乙二醇）-聚（丙交酯-共-乙交酯）（PLGA-PEG-PLGA）三嵌段共聚物。评价了共聚物1、2、3和4的不同嵌段长度对体外LNG释放的影响。含有0.5%w/v吐温-80的磷酸盐缓冲盐水（pH 7.4）用作体外释放介质。释放的LNG的量通过高压液相色谱（HPLC）方法测定。从相敏和热敏聚合物递送系统观察到LNG的受控（零级）体外释放。将相敏聚合物的浓度从5%增加到30%显著（p <0.05）将LNG的释放速率从38.32 μ g/天降低到31.45 μ g/天;并且增加溶剂混合物的亲水部分（即，BA）显著（p <0.05）增加了LNG的释放速率。在热敏聚合物递送系统的情况下，增加共聚物的疏水PLGA嵌段长度显著（p <0.05）降低了LNG的释放速率（98.65 μ g/天至67.60 μ g/天）。从这项研究中可以明显看出，相敏和热敏聚合物都适用于开发用于避孕激素的延长释放的可注射递送系统。
The objective of this research is to develop injectable controlled delivery systems for the contraceptive hormone, levonorgestrel (LNG), using phase sensitive and thermosensitive polymers. A combination of poly (lactide) (PLA) and a solvent mixture of benzyl benzoate (BB) and benzyl alcohol (BA) was used in the phase-sensitive polymer delivery systems. The effects of solvent systems and polymer concentrations on the in vitro LNG release were evaluated. In the case of thermosensitive polymer delivery systems, a series of low-molecular-weight poly (lactide-co-glycolide)-poly (ethylene glycol)-poly (lactide-co-glycolide) (PLGA-PEG-PLGA) triblock copolymers with varying ratios of lactide/glycolide (LA/GA, 2.0–3.5) were used. The effects of varying block length of copolymers 1, 2, 3, and 4 on the in vitro LNG release were evaluated. Phosphate buffer saline (pH 7.4) containing 0.5% w/v Tween-80 was used as in vitro release medium. The amount of the released LNG was determined by an high pressure liquid chromatography (HPLC) method. A controlled (zero-order) in vitro release of LNG was observed from both phase-sensitive and thermosensitive-polymer delivery systems. Increasing the concentration of the phase-sensitive polymer from 5% to 30% significantly (p< 0.05) decreased the release rate of LNG from 38.32 µg/day to 31.45 µg/day; and increasing the hydrophilic fraction of the solvents mixture (i.e., BA) significantly (p< 0.05) increased the release rate of LNG. In the case of the thermosensitive polymer delivery system, increasing the hydrophobic PLGA block length of copolymers significantly (p< 0.05) decreased the release rate of LNG (98.65 µg/day to 67.60 µg/day). It is evident from this study that both the phase sensitive and thermosensitive polymers are suitable for developing prolonged-release injectable delivery systems for the contraceptive hormone.