Department of Pharmaceutical Technology, Friedrich Schiller University Jena, Jena, Germany.
J Liposome Res. 2010 Mar;20(1):38-48. doi: 10.3109/08982100903030263.
Temoporfin (mTHPC) is a potent second-generation synthetic photosensitizer. Topical delivery of mTHPC is of great interest for the photodynamic therapy of psoriasis and superficial skin cancer lesions. The aim of this study was to evaluate the stability of hydrophilic gels containing mTHPC-loaded liposomes. Two different mTHPC-loaded liposome dispersions, composed of 15 % (w/w) nonhydrogenated soybean lecithin of different phosphatidylcholine content, were prepared and incorporated (2:1 w/w) into hydrogels of different carbomer concentrations (1.5, 2.25, and 3%; w/w). Obtained liposomal hydrogels, containing 0.15% (w/w) mTHPC, 10% (w/w) phospholipids, and 0, 0.5, or 1% (w/w) carbomer, were analyzed for flow properties, liposome particle size, and polydispersity index (PDI), pH value, and mTHPC content after their preparation and at predetermined time intervals during 6 months of storage at 4 and 23 degrees C. All hydrogels showed, during the whole period of investigation, adequate characteristics for topical application (i.e., they revealed shear-thinning plastic flow behavior). Rheological parameters, particle size, and PDI of liposomes in hydrogels, mTHPC content, and pH value did not show remarkable changes during the storage of gels, which could make them unacceptable for topical use. The obtained results indicated physical and chemical stability of liposomal gels containing mTHPC during 6 months of storage at both temperatures.
替莫泊芬（mTHPC）是一种有效的第二代合成光敏剂。mTHPC 的局部递送对于银屑病和浅表皮肤癌病变的光动力疗法非常有意义。本研究的目的是评估含有载 mTHPC 脂质体的亲水性凝胶的稳定性。制备了两种不同的载 mTHPC 脂质体分散体，由不同磷脂酰胆碱含量的 15％（w/w）氢化大豆卵磷脂组成，并将其（2：1 w/w）掺入不同卡波姆浓度（1.5、2.25 和 3％；w/w）的水凝胶中。含有 0.15％（w/w）mTHPC、10％（w/w）磷脂和 0、0.5 或 1％（w/w）卡波姆的载 mTHPC 脂质体水凝胶的流变性、脂质体粒径和多分散指数（PDI）、pH 值和 mTHPC 含量进行了分析。这些水凝胶在制备后以及在 4 和 23°C 下储存 6 个月的预定时间间隔内进行了分析。在整个研究期间，所有水凝胶均表现出良好的局部应用特性（即，它们表现出剪切稀化的塑性流动行为）。水凝胶中脂质体的流变学参数、粒径和 PDI、mTHPC 含量和 pH 值在凝胶储存期间均未发生明显变化，这可能使它们无法接受用于局部使用。结果表明，在两种温度下储存 6 个月时，含有 mTHPC 的脂质体凝胶具有物理和化学稳定性。
