Jensen Sabrine S, Jensen Henrik, Goodall David M, Østergaard Jesper
Department of Pharmacy, Faculty of Health and Medical Sciences, University of Copenhagen, Universitetsparken 2, DK-2100 Copenhagen, Denmark.
Paraytec Limited, York House, Outgang Lane, Osbaldwick, York, YO19 5UP, United Kingdom.
J Pharm Biomed Anal. 2016 Nov 30;131:113-123. doi: 10.1016/j.jpba.2016.08.018. Epub 2016 Aug 26.
UV imaging is capable of providing spatially and temporally resolved absorbance measurements, which is highly beneficial in drug diffusion, dissolution and release testing studies. For optimal planning and design of experiments, knowledge about the capabilities and limitations of the imaging system is required. The aim of this study was to characterize the performance of two commercially available UV imaging systems, the D100 and SDI. Lidocaine crystals, lidocaine containing solutions, and gels were applied in the practical assessment of the UV imaging systems. Dissolution of lidocaine from single crystals into phosphate buffer and 0.5% (w/v) agarose hydrogel at pH 7.4 was investigated to shed light on the importance of density gradients under dissolution conditions in the absence of convective flow. In addition, the resolution of the UV imaging systems was assessed by the use of grids. Resolution was found to be better in the vertical direction than the horizontal direction, consistent with the illumination geometry. The collimating lens in the SDI imaging system was shown to provide more uniform light intensity across the UV imaging area and resulted in better resolution as compared to the D100 imaging system (a system without a lens). Under optimal conditions, the resolution was determined to be 12.5 and 16.7 line pairs per mm (lp/mm) corresponding to line widths of 40μm and 30μm in the horizontal and vertical direction, respectively. Overall, the performance of the UV imaging systems was shown mainly to depend on collimation of light, the light path, the positioning of the object relative to the line of 100μm fibres which forms the light source, and the distance of the object from the sensor surface.
紫外成像能够提供空间和时间分辨的吸光度测量值，这在药物扩散、溶解和释放测试研究中非常有益。为了对实验进行最佳规划和设计，需要了解成像系统的能力和局限性。本研究的目的是表征两种市售紫外成像系统D100和SDI的性能。将利多卡因晶体、含利多卡因的溶液和凝胶应用于紫外成像系统的实际评估中。研究了利多卡因单晶在pH 7.4的磷酸盐缓冲液和0.5%（w/v）琼脂糖水凝胶中的溶解情况，以阐明在无对流流动的溶解条件下密度梯度的重要性。此外，通过使用网格评估了紫外成像系统的分辨率。发现垂直方向的分辨率比水平方向更好，这与照明几何形状一致。与D100成像系统（无透镜系统）相比，SDI成像系统中的准直透镜在紫外成像区域提供了更均匀的光强度，并产生了更好的分辨率。在最佳条件下，水平和垂直方向的分辨率分别确定为每毫米12.5和16.7线对（lp/mm），对应线宽分别为40μm和30μm。总体而言，紫外成像系统的性能主要取决于光的准直、光路、物体相对于形成光源的100μm纤维线的位置以及物体与传感器表面的距离。
