Title
Dermatocosmetics based on hydroxypropyl cellulose for acne treatment. Rheological and drug delivery behaviour
Authors
LACRAMIOARA OCHIUZ MANUELA HORTOLOMEI IULIAN STOLERIU and MARIA BERCEA

Received Dedicated to the 50^th anniversary of Cellulose Chemistry and Technology
Published Volume 50 Issue 5-6 May-June
Keywords hydroxypropyl cellulose, erythromycin, magnolol, acne, viscoelasticity, thermosensitive

Abstract
Aiming to develop some dermatocosmetic products with an anti-acne action, we propose a formulation of gels based on hydroxypropyl cellulose (HPC) loaded with two antimicrobial substances: erythromycin (ER) and magnolol (MG). The characteristics of these formulations were assessed from the rheological and pharmacotechnical points of view. The viscoelastic moduli of the HPC based systems increased in the presence of the drug substance. By introducing the magnolol, the system became thermosensitive and its behaviour changed from liquid-like at 20 °C to solid-like at 37 °C. In addition, changes in the flow curves were observed. The in vitro dissolution tests showed a greatly enhanced release of ER in the presence of MG. MG presented permeation properties superior to those of ER under ex vivo test conditions. The release of both ER and MG is based on diffusion, as revealed by the fitting to the Korsmeyer–Peppas model. The HPC has proved great compatibility with both ER and MG. These results recommend further clinical investigations of the HPC dermatocosmetics formulated and characterized in this study.