title: Solid lipid nanoparticles for transdermal delivery of avanafil: optimization, formulation, in-vitro and ex-vivo studies.
abstract: BACKGROUND
  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.
  
  
  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.
  
  
  CONCLUSIONS
  HPMC transdermal film-loaded AVA SLNs is an effective and alternative to per-oral drug administration.
authors.affiliation: a Department of Pharmaceutics and Industrial Pharmacy , Faculty of Pharmacy, Advanced Pharmaceutics and Nanotechnology Lab, King Abdulaziz University , Jeddah , Saudi Arabia .|b Department of Chemistry , Faculty of Science, Polymer Research Lab, King Abdulaziz University , Jeddah , Saudi Arabia .
authors.forename: Mallesh
authors.initials: M
authors.lastname: Kurakula
authors.affiliation: a Department of Pharmaceutics and Industrial Pharmacy , Faculty of Pharmacy, Advanced Pharmaceutics and Nanotechnology Lab, King Abdulaziz University , Jeddah , Saudi Arabia .|c Department of Pharmaceutics and Industrial Pharmacy , Faculty of Pharmacy, Minia University , Minia , Egypt , and.
authors.forename: Osama A A
authors.initials: OA
authors.lastname: Ahmed
authors.affiliation: a Department of Pharmaceutics and Industrial Pharmacy , Faculty of Pharmacy, Advanced Pharmaceutics and Nanotechnology Lab, King Abdulaziz University , Jeddah , Saudi Arabia .
authors.forename: Usama A
authors.initials: UA
authors.lastname: Fahmy
authors.affiliation: a Department of Pharmaceutics and Industrial Pharmacy , Faculty of Pharmacy, Advanced Pharmaceutics and Nanotechnology Lab, King Abdulaziz University , Jeddah , Saudi Arabia .|d Department of Pharmaceutics and Industrial Pharmacy , Faculty of Pharmacy, Al-Azhar University , Cairo , Egypt.
authors.forename: Tarek A
authors.initials: TA
authors.lastname: Ahmed
mesh_terms: D000279:Administration, Cutaneous; D000818:Animals; D001682:Biological Availability; D002626:Chemistry, Pharmaceutical; D016503:Drug Delivery Systems; D008055:Lipids / Q000737:chemistry*; D053758:Nanoparticles / Q000737:chemistry*; D010316:Particle Size; D011743:Pyrimidines / Q000008:administration & dosage* / Q000493:pharmacokinetics*; D051381:Rats; D017208:Rats, Wistar; D012867:Skin / Q000737:chemistry / Q000378:metabolism; D012869:Skin Absorption; D012995:Solubility; D013499:Surface Properties
chemical_list: D008055:Lipids; D011743:Pyrimidines; C553414:avanafil
keywords: Avanafil; optimization; skin permeation; solid lipid nanoparticles; transdermal films