Department of Pharmaceutics and Analytical Chemistry, Faculty of Health and Medical Sciences, University of Copenhagen, Universitetsparken 2, DK-2100 Copenhagen, Denmark.
Eur J Pharm Sci. 2012 May 12;46(1-2):72-8. doi: 10.1016/j.ejps.2012.02.011. Epub 2012 Feb 23.
A novel real-time UV imaging approach for non-intrusive investigation of the diffusion and partitioning phenomena occurring during piroxicam release from medium chain triglyceride (MCT) solution into two hydrogel matrices is described. Two binary polymer/buffer gel matrices, 0.5% (w/v) agarose and 25% (w/v) Pluronic F127, were applied as simple models mimicking the subcutaneous tissue. The evolution of the absorbance maps as a function of time provided detailed information on the piroxicam release processes upon the exposure of the gel matrices to MCT. Using calibration curves, the concentration maps of piroxicam in the UV imaging area were determined. Regression of the longitudinal concentration-distance profiles, which were obtained using expressions derived from Fick's second law, provided the diffusivity and the distribution coefficients of piroxicam penetrated into the gels. The obtained MCT-agarose (pH 7.4) distribution coefficient of 1.4 was identical to the MCT-aqueous (pH 7.4) distribution coefficient determined by the shake-flask method whereas that of the MCT-Pluronic F127 system was four times less. The experimental data show that UV imaging may have considerable potential for investigating the transport properties of drug formulations intended for the subcutaneous administration.
一种新颖的实时紫外成像方法,用于非侵入性研究吡罗昔康从中链甘油三酯(MCT)溶液释放到两种水凝胶基质中时发生的扩散和分配现象。两种二元聚合物/缓冲凝胶基质,0.5%(w/v)琼脂糖和 25%(w/v)Pluronic F127,被用作模拟皮下组织的简单模型。吸收图谱随时间的演变提供了关于凝胶基质暴露于 MCT 时吡罗昔康释放过程的详细信息。使用校准曲线,确定了在 UV 成像区域中吡罗昔康的浓度图谱。使用从菲克第二定律推导出的表达式对获得的纵向浓度-距离分布进行回归,提供了渗透到凝胶中的吡罗昔康的扩散系数和分配系数。在 pH 7.4 时,MCT-琼脂糖(pH 7.4)的分配系数为 1.4,与通过摇瓶法确定的 MCT-水(pH 7.4)分配系数相同,而 MCT-Pluronic F127 系统的分配系数则小四倍。实验数据表明,紫外成像在研究用于皮下给药的药物制剂的传输性质方面可能具有相当大的潜力。