CONTEXT: Avanafil (AVA) is used in the treatment of erectile dysfunction, but is 
reported for its poor aqueous solubility. Solid lipid nanoparticles (SLNs) are 
lipid carriers that can greatly enhance drug solubility and bioavailability.
OBJECTIVE: This work was aimed to formulate and optimize AVA SLNs with 
subsequent loading into hydrogel films for AVA transdermal delivery.
MATERIALS AND METHODS: AVA SLNs were prepared utilizing homogenization followed 
by ultra-sonication technique. The prepared SLNs were characterized for particle 
size, charge, surface morphology and drug content. The optimized SLNs 
formulation was incorporated into transdermal films prepared using HPMC and 
chitosan. Hydrogel films were evaluated for ex-vivo rat skin permeation using 
automated Franz diffusion cells. The permeation parameters and the release 
mechanism were evaluated. The transdermal permeation of the prepared AVA SLNs 
through the skin layers was studied using confocal laser scanning microscope.
RESULTS: Lipid concentration and % of oil in lipid had a pronounced effect on 
particle size while, entrapment efficiency was significantly affected by lipid 
concentration and % of cholesterol. The optimized AVA SLNs showed particle size 
and entrapment efficiency of 86 nm and 85.01%, respectively. TEM images revealed 
spherecity of the particles. High permeation parameters were observed from HPMC 
films loaded with AVA SLNs. The release data were in favor of Higuchi diffusion 
model. The prepared AVA SLNs were able to penetrate deeper in skin layers.
CONCLUSION: HPMC transdermal film-loaded AVA SLNs is an effective and 
alternative to per-oral drug administration.