Niemi L, Kahela P, Turakka L
Acta Pharm Nord. 1989;1(1):23-30.
The release of hydrocortisone was determined in vitro from o/w-creams containing an anionic (sodium lauryl sulphate), a cationic (cetrimide) or a nonionic (cetomacrogol 1000) surfactant as emulgator and different amounts of water. The solubility of hydrocortisone in water-emulgator systems and the solubilizing capacity of these emulgators for hydrocortisone were also determined. The release of hydrocortisone from creams containing emulgators increased in the same order as the solubilizing capacity of these emulgators for hydrocortisone, which indicates how important the concentration of dissolved hydrocortisone in the cream is for release. The effect of water content on the release of hydrocortisone was also dependent on the emulgator used. With a nonionic emulgator, release was enhanced slightly as the water content in the cream increased. In the case of ionic emulgators, release of hydrocortisone was retarded as the amounts of water in the cream increased up to 60% water content; above this, the release was enhanced, probably owing to changes in the liquid crystalline microstructure of the cream.
在体外测定了氢化可的松从含有阴离子型（十二烷基硫酸钠）、阳离子型（西曲溴铵）或非离子型（聚氧乙烯鲸蜡醚1000）表面活性剂作为乳化剂以及不同水量的水包油乳膏中的释放情况。还测定了氢化可的松在水 - 乳化剂体系中的溶解度以及这些乳化剂对氢化可的松的增溶能力。氢化可的松从含有乳化剂的乳膏中的释放量按照这些乳化剂对氢化可的松的增溶能力的相同顺序增加，这表明乳膏中溶解的氢化可的松浓度对释放的重要性。含水量对氢化可的松释放的影响也取决于所使用的乳化剂。使用非离子型乳化剂时，随着乳膏中含水量的增加，释放略有增强。在离子型乳化剂的情况下，当乳膏中的水量增加至含水量60%时，氢化可的松的释放受到抑制；超过此含量，释放增强，这可能是由于乳膏液晶微观结构的变化所致。
