Pereira Joana, Gonçalves Rita, Barreto Margarida, Dias Clarisse, Carvalho Fátima, Almeida António J, Ribeiro Helena Margarida, Marto Joana
Research Institute for Medicines (iMed.ULisboa), Faculty of Pharmacy, Universidade de Lisboa, 1649-003 Lisbon, Portugal.
LEF Infosaúde, Rua das Ferrarias del Rei, 6, 2730 269 Barcarena, Portugal.
Pharmaceutics. 2020 Apr 26;12(5):398. doi: 10.3390/pharmaceutics12050398.
Hypopigmentation is a progressive dermatological condition caused by a reduction in the skin pigment, melanin. Its treatment is considered a challenge due to the lack of a highly efficient single therapy. Currently, the main treatments include photochemotherapy, application of corticosteroids and immunosuppressants, and laser. Khellin-based gel-in-oil emulsions appear as a promising alternative since they ensure a concentration of the drug, a natural furanochromone, at the desired location, skin surface. Khellin promotes repigmentation as it forms a dark colored complex after solar irradiation. The aim of this study was the development and characterization (e.g., rheological behaviour, droplet size, tackiness, adhesion and spreadability) of three topical gel-in-oil emulsions prepared with different emollients, formulated through a cold emulsification process, and suitable for the incorporation of khellin. In vitro studies were performed to evaluate the drug release and permeation profiles across artificial membranes and excised human skin, respectively, using Franz-type vertical diffusion cells. The W/O emulsions developed showed macroscopic appearance, shear-thinning behavior with a mean droplet size from 3.28 to 4.28 μm, suitable for topical application. In vitro studies revealed permeation values of about 1% of khellin across the stratum corneum, making these gel-in-oil emulsions promising for preclinical and clinical studies. The cold process, being an easy and low energy production method, represents an innovative strategy to produce khellin-based gel-in-oil emulsions to treat patients with hypopigmentation.
色素减退是一种由皮肤色素黑色素减少引起的进行性皮肤病。由于缺乏高效的单一疗法，其治疗被认为是一项挑战。目前，主要治疗方法包括光化学疗法、应用皮质类固醇和免疫抑制剂以及激光治疗。基于凯林的油包凝胶乳液似乎是一种有前景的替代方法，因为它们能确保一种天然呋喃色酮药物在所需位置即皮肤表面达到一定浓度。凯林在太阳照射后形成深色复合物，从而促进色素再生。本研究的目的是开发并表征三种用不同润肤剂制备的外用油包凝胶乳液，这些乳液通过冷乳化工艺配制，适合加入凯林。分别使用弗兰兹型垂直扩散池进行体外研究，以评估药物在人工膜和离体人皮肤上的释放和渗透情况。所开发的油包水乳液外观良好，具有剪切变稀行为，平均液滴尺寸为3.28至4.28μm，适合局部应用。体外研究显示，凯林透过角质层的渗透值约为1%，这使得这些油包凝胶乳液在临床前和临床研究中具有前景。冷工艺作为一种简单且低能耗的生产方法，是生产用于治疗色素减退患者的基于凯林的油包凝胶乳液的一种创新策略。
