Purpose

We aimed to investigate the effect of solubility parameter and drug concentration on the rheological behaviour of drug-in-adhesive films intended for transdermal application.

Methods

Films were prepared over a range of drug concentrations (5%, 10% and 20% w/w) using ibuprofen, benzoic acid, nicotinic acid and lidocaine as model drugs in acrylic (Duro-Tak 87-4287 and Duro-Tak 87900A) or silicone (Bio-PSA 7-4301 and Bio-PSA 7-4302) pressure sensitive adhesives (PSAs). Saturation status of films was determined using light microscopy. Viscoelastic parameters were measured in rheology tests at 32°C.

Results

Subsaturated films had lower viscoelastic moduli whereas saturated films had higher moduli than the placebo films and/or a concentration-dependent increase in their modulus. Saturation concentration of each drug in the films was reflected by decreasing/increasing viscoelastic patterns. The viscoelastic windows (VWs) of the adhesive and drug-in-adhesive films clearly depicted the effect of solubility parameter differences, molar concentration of drug in the adhesive film and differences in PSA chemistry.

Conclusions

Drug solubility parameters and molar drug concentrations have an impact on rheological patterns and thus on the adhesive performance of tested pressure sensitive adhesives intended for use in transdermal drug delivery systems. Use of the Flory equation in its limiting form was appropriate to predict drug solubility in the tested formulations.

中文翻译：

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药物包胶型透皮膜中压敏胶粘弹性性能的研究

目的

我们旨在研究溶解度参数和药物浓度对用于透皮应用的药物包胶薄膜的流变行为的影响。

方法

使用布洛芬、苯甲酸、烟酸和利多卡因作为丙烯酸中的模型药物（Duro-Tak 87-4287 和 Duro-Tak 87900A）在一系列药物浓度（5%、10% 和 20% w/w）上制备薄膜或硅胶（Bio-PSA 7-4301 和 Bio-PSA 7-4302）压敏粘合剂 (PSA)。使用光学显微镜确定膜的饱和状态。粘弹性参数在 32°C 下的流变测试中测量。

结果

次饱和薄膜具有较低的粘弹性模量，而饱和薄膜具有比安慰剂薄膜更高的模量和/或其模量的浓度依赖性增加。薄膜中每种药物的饱和浓度通过减少/增加粘弹性模式来反映。粘合剂膜和粘合剂中药物膜的粘弹性窗口 (VW) 清楚地描绘了溶解度参数差异、粘合剂膜中药物摩尔浓度和 PSA 化学差异的影响。

结论

药物溶解度参数和摩尔药物浓度对流变学模式有影响，因此对用于透皮给药系统的测试压敏粘合剂的粘合性能有影响。以限制形式使用 Flory 方程适用于预测药物在测试制剂中的溶解度。