Since many decades, phytoconstituents are well known for their potential therapeutic benefits but the development of herbal products has been limited due to difficulties like collection, isolation, stability and aqueous solubility of the phytoconstituents. The present study focuses on the development of microemulsion-based sunscreen cream formulation containing therapeutically active phytoconstituents like lycopene, β-carotene and curcumin which are reported for both antioxidant and ultraviolet radiation barrier properties. But the major hurdle in the development of the formulation is poor solubility and stability of these 3 components. Microemulsion preparation helps to enhance the solubility and stability of the final product. Screening of oils, surfactants and cosurfactants were done based on solubility studies followed by the construction of pseudo-ternary phase diagrams, sesame oil, span 80 to tween 80 (surfactant) and isopropyl alcohol (co-surfactant) which were selected to stable microemulsion. Based on a solubility study of components and pseudo-ternary phase diagrams, surfactant to co-surfactant (Smix) with 2:1 ratio and oil to Smix with 2:8 ratio were selected for preparation of the final microemulsion. Results show an average globule size of 208 nm, conductance 0.935 moh/cm, pH 7.1, zeta potential − 17.5 mV, refractive index 1.002, polydispersibility index 0.342, percent transmittance 90.68% and viscosity 82.45 cps. In a drug content study, the presence of lycopene, β-carotene and curcumin was found to be 87.53, 85.08 and 90.65%, respectively. Finally, microemulsion-based sunscreen cream was prepared and evaluated for various parameters like pH, extrudability, spreadability and drug content study. The sun protection factor (SPF) of microemulsion and cream was found to be 36.32 and 37.65, respectively. The stability study data shows better stability of the final formulation. Formulation of microemulsion-based sunscreen cream may be a better option in the design and development of herbal phytoconstituents.

中文翻译：

---

一种新型的基于草药微乳液的紫外线防护霜的制造和表征方法

几十年来，植物成分以其潜在的治疗益处而闻名，但由于诸如植物成分的收集，分离，稳定性和水溶性等困难，草药产品的开发受到了限制。本研究致力于开发基于微乳液的防晒霜配方，该配方包含具有治疗活性的植物成分，如番茄红素，β-胡萝卜素和姜黄素，据报道它们具有抗氧化剂和紫外线辐射的阻隔性能。但是制剂开发中的主要障碍是这三种组分的不良溶解性和稳定性。微乳液制备有助于增强最终产品的溶解性和稳定性。筛选油 表面活性剂和助表面活性剂是根据溶解度研究完成的，然后构造伪三元相图，芝麻油，跨度为80至吐温80（表面活性剂）和异丙醇（辅助表面活性剂），选择它们来稳定微乳液。基于对组分的溶解度研究和拟三元相图，选择表面活性剂与助表面活性剂（Smix）的比例为2：1，油与混合物的比例为2：8，以制备最终的微乳液。结果显示平均小球尺寸为208 nm，电导为0.935 moh / cm，pH 7.1，ζ电位-17.5 mV，折射率为1.002，多分散性指数为0.342，透光率百分比为90.68％，粘度为82.45 cps。在一项药物含量研究中，发现番茄红素，β-胡萝卜素和姜黄素的含量分别为87.53、85.08和90.65％。最后，制备了基于微乳液的防晒霜，并评估了各种参数，例如pH值，可挤出性，铺展性和药物含量研究。发现微乳液和乳霜的防晒系数（SPF）分别为36.32和37.65。稳定性研究数据显示最终制剂具有更好的稳定性。基于微乳液的防晒霜配方可能是草药植物成分设计和开发中的更好选择。