Optimizing the dermal accumulation of a tazarotene microemulsion using skin deposition modeling

Abstract

Context: It is well known that microemulsions are mainly utilized for their transdermal rather than their dermal drug delivery potential due to their low viscosity, and the presence of penetration enhancing surfactants and co-surfactants.

Objective: Applying quality by design (QbD) principles, a tazarotene microemulsion formulation for local skin delivery was optimized by creating a control space.

Materials and methods: Critical formulation factors (CFF) were oil, surfactant/co-surfactant (SAA/CoS), and water percentages. Critical quality attributes (CQA) were globular size, microemulsion viscosity, tazarotene skin deposition, permeation, and local accumulation efficiency index.

Results and discussion: Increasing oil percentage increased globular size, while the opposite occurred regarding SAA/CoS, (p?=?0.001). Microemulsion viscosity was reduced by increasing oil and water percentages (p?p?=?0.009). Models with very good fit were generated, predicting the effect of CFF on globular size, microemulsion viscosity, and drug deposition. A combination of 40% oil and 45% SAA/CoS showed the maximum drug deposition of 75.1%. Clinical skin irritation study showed that the aforementioned formula was safe for topical use.

Conclusion: This article suggests that applying QbD tools such as experimental design is an efficient tool for drug product design.