title: Formulation and optimization of nano-sized ethosomes for enhanced transdermal delivery of cromolyn sodium.
abstract: OBJECTIVE
  The current study was aimed to investigate the feasibility of transdermal delivery of cromolyn sodium using a novel lipid vesicular carrier, ethosomes.
  
  
  METHODS
  Ethosomes of cromolyn sodium was prepared, optimized, and characterized for vesicle shape, vesicle size and size distribution, zeta potential, entrapment efficiency, in vitro drug release, in vitro skin permeation, in vitro skin deposition and vesicle stability. Histological examination of porcine ear skin treated with optimized ethosomal formulation was performed to study the change of skin morphologies.
  
  
  RESULTS
  The optimized cromolyn sodium ethosomes showed reasonable entrapment efficiency (49.88±1.84%), optimum nanometric size range (133.8 ± 7.5 nm), and high zeta potential (-69.82 ± 1.2 mV). In vitro drug release studies of optimized ethosomal formulation through cellophane membrane showed an enhanced and sustained delivery of drug compared to conventional liposomes, hydroethanolic, (45% v/v) and phosphate buffer saline PBS pH 7.4 drug solutions. The optimized ethosomal formulation showed significantly-enhanced transdermal flux (18.49 ± 0.08 mg/cm(2)/h) across porcine ear skin as compared to liposome (1.80 ± 0.12 mg/cm(2)/h), hydroethanolic drug solution (4.45 ± 0.71 mg/cm(2)/h), and PBS pH 7.4 drug solution (1.18 ± 0.35 mg/cm(2)/h). Moreover, ethosomal formulation showed better skin drug deposition (10.28 ± 0.67%) and shortest lag time (0.11 ± 0.09 h) for cromolyn sodium.
  
  
  CONCLUSIONS
  Our significant results suggest that ethosomes can be a promising tool for transdermal delivery of cromolyn sodium.
authors.affiliation: Department of Pharmaceutics, Amrita School of Pharmacy, Amrita Vishwa Vidyapeetham University, Health Sciences Campus, Kochi, Kerala, India.
authors.forename: R
authors.initials: R
authors.lastname: Rakesh
authors.forename: K R
authors.initials: KR
authors.lastname: Anoop