Research On Dexamethasone Acetate Solid Lipid Nanoparticles Gel

Solid lipd nanoprticles(SLN) are colloidal system for controlled drug delivery and followed by the development of emulsion, liposomes, microparticles and nanoparticles based on synthetic polymers. It is a promising drug delivery system with solid,biodegradable lipid as drug carriers, diameters ranging between 50-1000 nanometers,which has the advantages of controlled drug release,high physical stability,low toxicity and large scale production etc.Solvent emulsification/evaporation method was used to prepare solid lipid nanoparticles gel and Dexamethasone acetate(DA)as the model drug.This preparation with more bioavailability of DA and fewer adverse reactions comparing toother transdermal preparations.The entrapped efficiency(EE) of drug was determined spectrophoto- metrically by Ultraviolet absorbance at 239nm after the free drug molecules was separated from DA-SLN on a sephadexG-50 minicolumn.The best formulation of the DA-SLN was optimized by orthogonal design, the entrapment efficiency, drug loading and diameter were taken as criteria. The quality of the DA-SLN was evaluated (Zetasizer Nano ZS90 and electroscopy ,etc) .The results showed the mean diameter of the DA-SLN suspension was 180.8nm,the Zate potential was -31.24mv.The optimal formulation of EE was78.71±0.57%,and DL was 3.21±0.54%. Results of the stability experiments indicated that the DA-SLN suspension could be kept stable at 4℃for 30 days.An HPLC method was established for determination of the contents of Dexamethasone acetate in solid lipd nanoprticles gel. Carbopol 940 was used as the matrix in gel formed. Results of the stability experiments indicated that the DA-SLN gel could be kept stable at 4℃for 40 days.Compared to Dexamethasone acetate cream,the DA-SLN gel had fewer transdermal penetration and more accumulation of skin.It indicated that SLN can raise the accumulation of skin remarkably and reduce the transdermal penetration to blood markedly.The results of preliminary pharmacodynamics showed that theDA-SLN gel had more effective anti-inflammatory than DA-cream.