Evaluation of bases for topical preparations by microdialysis

用微透析法测定了水杨酸、吲哚美辛外用制剂和透皮制剂中基质的作用以及曲尼司特透皮吸收促进剂的作用。所考察的软膏基质分别为索尔碱、宝丽来、白色凡士林、亲水宝丽来吸收软膏、亲水软膏。采用市售消炎痛凝胶剂和乳膏制剂。研究结果如下：(1)透析液中水杨酸的回收率为4.8%。(2)在SOLBASE的情况下，水杨酸向完整皮肤的转移明显少于无角质层的皮肤。完整皮肤组织中水杨酸的最大浓度为68mU/L，去除粉刺层可使水杨酸浓度增加5倍。(3)在蜂胶的情况下，水杨酸的转移较好，完整皮肤组织中的最大浓度为622亩M。白石油也有类似的结果。(4)亲水抛光膏和吸湿软膏的结果与抛光膏相似。(5)疏水基质和吸收软膏的皮肤组织浓度曲线下面积与血药浓度曲线下面积与时间的比值较大。这些结果表明，疏水基质和吸收软膏可作为局部作用药物的基质。(6)样品中吲哚美辛的回收率为5.2%。吲哚美辛从亲水性软膏和吸收软膏向皮肤组织的转移良好，皮肤组织中的最大浓度为30-65亩M，商业制剂中的结果与此相似。(7)20%油酸和10%丙二醇组成为曲尼司特的吸收促进剂效果最好。(8)微透析法是评价外用透皮给药制剂功能的有效方法。

Microdialysis has been used to determine effects of bases for topicaland transdermal preparations of salicylic acid , indomethacin and effects of absorption enhancer for transdermal delivery of tranilast. The ointment bases examined were solbase, poloid, white petrolatum, hydrophilic poloid absorptive ointment, hydrophilic ointment. Also, gel and cream preparation of indomethacin on market were used. Results obtained in this study were as folows :(1) Recovery % of salicylic acid in the dialysate was 4.8%. (2) In case of solbase, transfer of salicylic acid to intact skin was remarkably less than the skin without stratum corneum. maximum concentration of salicylic acid in intact skin tissue was 68mu M and the value increased by5Ot imes by removal of stratum comeum. (3)In case of poloid, transfer of salicylic acid was fairly good and maximaum concentration in intact skin tissue was 622mu M.White petrolaum showed similar results. (4) Hydrophilic poloid and absorptive ointment showed similar results to poloid. (5)Theratio of area under the curve of concentration in skin tissue vs. time to area under the curve of concentration in plasma was greater in hydrophobic base and absorptive ointment. These results suggest that hydrophobic base and absorptive ointment are useful as a base for drugs of topical action. (6)Recovery % of indomethacin in the daillysate was 5.2%. Transfer of indomethacin to skin tissue from hydrophilic ointment and absorptive ointment was good and maximum concentration in skin tissue was 30-65mu M.Similar results was obtained in commercial preparations of indomethacin. (7)A mixture of oleic acid 20% and propyleneglycol 10% was most effectve as a absorption enhancer for tranilast. (8)Finally, it is recognized that microdialysis is a useful technique for evaluation of function of topical transdermal delivery preparations.