Development and Evaluation of Khellin-loaded Microemulgel for Dermatological Applications^{[ # ]}

Abstract

Microemulsions are optically nanosized emulsions, isotropic and thermodynamically stable. They represent versatile drug delivery systems with high potential because they can be administered regardless of route. In the present study, we report on the formulation of a microemulsion made with glycerol (2.25%), Labrasol (20.25%) vitamin E acetate (2.50%), and water (75.00%), which was developed using the pseudo-ternary phase diagram. Globules of the microemulsion had PdI less than 0.25 and size of about 17 nm, evaluated by DLS analysis. These values did not change after loading khellin, a natural lipophilic molecule with interesting biological activities, used as a model of lipophilic drug. Carboxymethyl cellulose was selected as gelling polymer to obtain a microemulgel. Viscosity was 22 100.0 ± 1555.6 mPas·s at 21 ± 2 °C, while it was 8916.5 ± 118.1 mPas·s at 35 ± 2 °C, remaining stable over time. Khellin recovery was 93.16 ± 4.39% and was unchanged after 4 weeks of storage (93.23 ± 2.14%). The pH was 6.59 ± 0.19 and it was found to be 6.42 ± 0.34 at the end of the storage lifetime. The diffusion of khellin from the developed formulation was prolonged over an extended period. Based on overall results and due to the dermatological properties of the ingredients of the formulation, the developed microemulgel loaded with khellin is very promising and suitable for skin care applications.

Key words

Microemulsion - khellin - carboxymethyl cellulose - viscosity and release kinetics measurements - skin PAMPA - rabbit ear skin permeation

^# Dedicated to Professor Dr. Gerhard Franz on the occasion of his 85th birthday.

Publication History

Received: 07 January 2022

Accepted after revision: 03 March 2022

Accepted Manuscript online:
04 March 2022

Article published online:
25 May 2022

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