Paroxetine is not suitable for oral administration due to its extensive first-pass metabolism, thus resulting in less bioavailability. This study aimed to prepare novel paroxetine-loaded solid lipid nanoparticles (SLNs) based sustained-release transdermal patches to overcome these problems by enhancing drug absorption and bioavailability. Nine formulations of paroxetine SLNs were prepared by the hot melt-homogenization method using different concentrations of glycerol monostearate (Kolliwax) and Tween 80. Then these prepared SLNs were incorporated in a matrix type transdermal patch having a matrix of ethyl cellulose and polyvinyl pyrrolidone in 3:2 with polyvinyl alcohol. The SLNs showed a particle size range of 113-230 nm and an entrapment efficiency of 85.14%. The SLNs showed sustained paroxetine release (77.86-95.63% release) up to 48 h. FTIR studies showed no interaction between drug and formulation components. Paroxetine is evenly distributed in an amorphous form in SLNs, as demonstrated by DSC as well as PXRD analysis. SLNs formulated patches showed higher drug permeation through the skin than drug-based transdermal patches., Draize patch test revealed no sign of erythema after applying paroxetine-loaded SLN patches (score 0) as observed with the marketed product. The developed SLNs based transdermal patches showed increased permeability and sustained release behaviour.
Keywords: Paroxetine; ethylcellulose; ex vivo permeation; polyvinyl pyrrolidone; solid lipid nanoparticles; transdermal patch.