title: Solid lipid nanoparticles (SLNs) for topical delivery of aceclofenac by using xanthan  gum: Ex vivo and in vivo evaluation.
abstract: Solid lipid nanoparticles (SLN) are very potential formulations for topical delivery of anti-inflammatory and anti-arthritic drugs. The solid state of the lipid particle enables efficient drug encapsulation and controlled drug release. In the present study the evaluation of different parameters based on variation of concentration of lipid and co-surfactant was studied. The SLN gel formulation of the same dispersion was compared with the SLN dispersion and with the marketed gel formulation of aceclofenac. At first the solid lipid nanoparticles were prepared by high speed homogenization and ultra-sonication method with fixed amount of aceclofenac (10%) and pluronic F68 (1.5%). The particle size, zeta potential and span was found to be within the range of 123 nm to 323 nm, -12.4 to -18.5 and 0.42 to 0.86 respectively as the lipid concentration was increasing from 7.5% to 40%. The highest entrapment efficiency was found to be 75% with the formulation having lipid concentration of 30% and 0.85% of phospholipon 90G (Phospholipid as co-surfactant). Particle surface morphology was measured by scanning electron microscope (SEM). Permeation rate and controlled release property of xanthan gum loaded SLN gel formulations and SLN dispersion was studied through the excised pig skin for 24hr and it was found that release rate of SLN gel formulation was more controlled as compare to SLN dispersions. In vivo pharmacodynamic study was carried out for 24 hr by injecting 0.1ml (w/v) CFA (Complete Fraud's Adjuvant). From the in vitro and in vivo study it was found that action of aceclofenac was enhanced by prepared SLN dispersion and gel formulations. The results indicated the utility of both SLN dispersion and SLN gel system for transdermal delivery of aceclofenac as excellent and logical.
authors.affiliation: Department of Pharmaceutical Sciences, Dibrugarh University,  Dibrugarh, Assam, 786004, India. s_dg2006@yahoo.co.in.
authors.forename: Sandipan
authors.initials: S
authors.lastname: Dasgupta
authors.forename: Bhaskar
authors.initials: B
authors.lastname: Mazumder
authors.forename: Surajit K
authors.initials: SK
authors.lastname: Ghosh
authors.forename: Surendra S
authors.initials: SS
authors.lastname: Kaurav