Nayak Atul, Das Diganta B, Chao Tzu C, Starov Victor M
Department of Chemical Engineering, Loughborough University, Loughborough LE11 3TU, Leicestershire, UK.
Department of Chemical Engineering, Loughborough University, Loughborough LE11 3TU, Leicestershire, UK.
J Pharm Sci. 2015 Dec;104(12):4109-4116. doi: 10.1002/jps.24625. Epub 2015 Sep 7.
The spreadability of a liquid drug formulation on skin is an indication of it either remaining stationary or distributing (spreading) as a droplet. Factors determining droplet spreadability of the formulation are spreading area, diameter of the droplet base, viscosity of the liquid, contact angle, volume of droplet on skin and any others. The creation of microcavities from the application of microneedle (MN) has the potential to control droplet spreading, and hence, target specific areas of skin for drug delivery. However, there is little work that demonstrates spreading of liquid drug formulation on MN-treated skin. Below, spreading of a lidocaine hydrogel formulation and lidocaine solution (reference liquid) on porcine skin is investigated over MN-treated skin. Controlled spreadability was achieved with the lidocaine hydrogel on MN-treated skin as compared with lidocaine solution. It was observed that the droplet spreading parameters such as spreading radius, droplet height and dynamic contact angle were slightly lower for the lidocaine hydrogel than the lidocaine solution on skin. Also, the lidocaine hydrogel on MN-treated skin resulted in slower dynamic reduction of droplet height, contact angle and reduced time taken in attaining static advancing droplets because of the MN microcavities.
液体药物制剂在皮肤上的铺展性表明其是保持静止还是以液滴形式分布(铺展)。决定制剂液滴铺展性的因素包括铺展面积、液滴底部直径、液体粘度、接触角、皮肤上的液滴体积以及其他因素。通过应用微针(MN)产生微腔有可能控制液滴铺展,从而将药物递送靶向皮肤的特定区域。然而,很少有研究证明液体药物制剂在经微针处理的皮肤上的铺展情况。下面,研究了利多卡因水凝胶制剂和利多卡因溶液(参比液体)在猪皮肤上经微针处理后的铺展情况。与利多卡因溶液相比,利多卡因水凝胶在经微针处理的皮肤上实现了可控的铺展性。观察到,利多卡因水凝胶在皮肤上的铺展半径、液滴高度和动态接触角等液滴铺展参数略低于利多卡因溶液。此外,由于微针微腔的存在,经微针处理的皮肤上的利多卡因水凝胶导致液滴高度和接触角的动态降低较慢,且达到静态前进液滴所需的时间减少。