Bio-based topical system for enhanced salicylic acid delivery: preparation and performance of gels.
OBJECTIVE
New salicylic acid (SA)-loaded gels were developed using excipients made from renewable materials, and our goal was to improve drug permeation in the topical treatment of acne vulgaris.


METHODS
We studied the preparation parameters to obtain suitable gel formulations. Only naturally occurring polymers were used as gelling agents. Two hydrogels and three lipogels were selected and characterized in terms of drug loading, pH, viability cells, rheology, mechanical properties and in vitro permeation; these hydrogels and lipogels were compared with the traditional ointment. We also evaluated skin parameters before and after gel application.


RESULTS
The formulations that we studied are non-Newtonian fluids; they have high drug loading and suitable mechanical properties. Lipogels exhibit a slower and more linear in vitro permeation profile compared with hydrogels. The different vehicles that we used affected drug permeation and improve patient compliance. Cytotoxicity studies suggest that all of the formulations are non-toxic.


CONCLUSIONS
Lipogels demonstrate appropriate technological features and improved performance compared with the traditional ointment with regard to their composition. Lipogels may represent a new bio-based topical system for SA delivery. The use of 'green' excipients leads to 'skin-friendly' formulations that are able to satisfy environmental safety.
Department of Chemistry and Pharmacy, University of Sassari, Sassari, Italy.
Rita
R
Langasco
Biocosmesi, Sedilo, Italy.
Gianpiera
G
Spada
Department of Pharmaceutical Technology, Faculty of Pharmacy, Ege University, Izmir, Turkey.
Sakine Tuncay
ST
Tanriverdi
Department of Chemistry and Pharmacy, University of Sassari, Sassari, Italy.
Giovanna
G
Rassu
Department of Chemistry and Pharmacy, University of Sassari, Sassari, Italy.
Paolo
P
Giunchedi
Department of Pharmaceutical Technology, Faculty of Pharmacy, Ege University, Izmir, Turkey.
Özgen
Ö
Özer
Department of Chemistry and Pharmacy, University of Sassari, Sassari, Italy.
Elisabetta
E
Gavini
D000152:Acne Vulgaris / Q000188:drug therapy; D000279:Administration, Cutaneous; D000287:Administration, Topical; D000328:Adult; D002626:Chemistry, Pharmaceutical; D004337:Drug Carriers; D016503:Drug Delivery Systems; D005079:Excipients; D005782:Gels / Q000737:chemistry; D006801:Humans; D010316:Particle Size; D010539:Permeability; D012212:Rheology; D020156:Salicylic Acid / Q000008:administration & dosage* / Q000378:metabolism / Q000627:therapeutic use; D012867:Skin / Q000378:metabolism*; D012869:Skin Absorption; D014783:Viscosity; D055815:Young Adult
D004337:Drug Carriers; D005079:Excipients; D005782:Gels; D020156:Salicylic Acid
gel; green formulation; renewable resources; skin permeation; topical delivery