title: Gellan gum fluid gels for topical administration of diclofenac.
abstract: Diclofenac topical formulations are often preferred for drug administration to patients who experience serious GIT problems. Absorption of the drug through the skin, however, can be challenging due to the natural protective feature of the stratum corneum (SC). In this article, fluid gels prepared from gellan gum were explored as a topical drug delivery vehicle. Rheological analysis of the formulations showed that it was possible to produce a topical gel with a viscosity and the mechanical strength similar to that of the commercially available Voltaren®gel using 1% w/w of a 50:50 low acyl/high acyl (LA/HA) gellan blend. Soft-tribology was used to assess the lubrication properties of gellan fluid gels. The lubrication of the gellan gum fluid gel formulations at high rubbing speeds was similar to the lubrication of the Voltaren®gel. The use of gellan gum dramatically increased skin permeation of diclofenac when compared with the commercially available formulation and could be controlled by changing the gellan gum concentration and/or sodium ion concentration in the formulation. This study highlights the potential use of fluid gels that can be easily tuned to have physical properties suitable for topical formulations with the added advantage of increasing drug permeation.
authors: Department of Pharmacy, University of Huddersfield, Queensgate, Huddersfield, HD1 3DH, UK.
authors: Mohammed H
authors: MH
authors: Mahdi
authors: Department of Pharmacy, University of Huddersfield, Queensgate, Huddersfield, HD1 3DH, UK; Institute of Skin Integrity and Infection Prevention, University of Huddersfield, Queensgate, Huddersfield, HD1 3DH, UK.
authors: Barbara R
authors: BR
authors: Conway
authors: School of Chemical Engineering, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK.
authors: Thomas
authors: T
authors: Mills
authors: Department of Pharmacy, University of Huddersfield, Queensgate, Huddersfield, HD1 3DH, UK; Institute of Skin Integrity and Infection Prevention, University of Huddersfield, Queensgate, Huddersfield, HD1 3DH, UK. Electronic address: a.m.smith@hud.ac.uk.
authors: Alan M
authors: AM
authors: Smith
mesh_terms: D000287:Administration, Topical; D000818:Animals; D002626:Chemistry, Pharmaceutical / Q000379:methods; D004008:Diclofenac / Q000008:administration & dosage* / Q000737:chemistry* / Q000378:metabolism; D016503:Drug Delivery Systems / Q000379:methods; D065546:Drug Liberation; D005079:Excipients / Q000737:chemistry; D005782:Gels / Q000737:chemistry*; D010539:Permeability; D011135:Polysaccharides, Bacterial / Q000737:chemistry*; D012212:Rheology; D012867:Skin / Q000378:metabolism*; D012869:Skin Absorption; D013552:Swine; D014783:Viscosity
chemical_list: D005079:Excipients; D005782:Gels; D011135:Polysaccharides, Bacterial; D004008:Diclofenac; C048288:gellan gum
keywords: Diclofenac; Fluid gel; Gellan gum; Rheology; Skin permeation; Topical; Tribology