Romanian Society of Pharmaceutical Sciences

« Back to Farmacia Journal 3/2021

PRELIMINARY STUDY REGARDING THE FORMULATION AND PHYSICAL EVALUATION OF SOME BIOCOMPATIBLE, OIL IN WATER MICROEMULSIONS WITH SALICYLIC ACID FOR DERMATOLOGIC USE

MARIA CRISTINA ANICESCU, CRISTINA ELENA DINU-PÎRVU, MIHAELA VIOLETA GHICA *,
MARINA THEODORA TALIANU, LĂCRĂMIOARA POPA

Department of Physical and Colloidal Chemistry, Faculty of Pharmacy, “Carol Davila” University of Medicine and Pharmacy, 6 Traian Vuia Street, Bucharest, Romania

Download Full Article PDF

Microemulsions (MEs) are considered a piece of new generation colloidal systems with high potential for drug delivery, especially for topical application. The present study had as main objectives the development and physical analysis of two groups of oil in water (O/W) microemulsion (ME) vehicles using a biocompatible mixture composed of lecithin/Tween 80 as surfactants and propylene glycol (PG) as cosurfactant. The addition of vegetable oils and hyaluronic acid (HA) enriched the quality profile of the systems. The vehicles were suitable to entrap salicylic acid (SA) 0.5% as a model drug with keratoplastic properties, and positive outcomes in acne treatment. The study was divided in two stages of screening, resulting two groups of MEs. In the first case, lecithin was tested as potential surfactant on a domain of 0.5 - 2%. A minimum amount of lecithin 0.5%, in association with Tween 80 and PG was considered appropriate to obtain the second group of O/W MEs. In this case, were screened combinations of lecithin/Tween 80/PG able to solubilize SA 0.5% and small quantities of vegetable oils. All the microdispersions obtained in both stages were analysed considering visual appearance, conductivity, pH and refractive index as important parameters for systems’ stability. The area of MEs generation for the second group, was specifically identified using graphical method. An extensive rheological analysis was considered to determine the flow behaviour for the most representative systems. It was concluded that minimal concentration of tensioactives that can promote stable and clear systems with SA was 30.5%. This proportion was specific for a ME system formulated with 20% Tween 80, 10%PG and 0.5% lecithin. Physical analysis performance emphasized preliminary data concerning the internal structure of microemulsions, offering a useful background for future studies.