Transdermal Delivery of Desmopressin Acetate from Water-in-Oil Nano/Submicron Emulsion Systems

Desmopressin acetate is a potent synthetic peptide hormone that is administered via parenteral, intranasal and oral routes. A more acceptable route of administration with potentially good bioavailability could be offered by transdermal delivery. The present work reports on the development of water-in-oil (w/o) microemulsions for the transdermal administration of desmopressin acetate. A water-in-oil nano/submicron emulsion for transdermal administration of desmopressin was developed. Its skin penetration profiles were determined using Franz-diffusion cell. Pseudo-ternary phase diagrams for emulsion regions were constructed. Effects of hydrophilic-lipophilic balance (HLB), ratio of surfactants and co-surfactant mixture to oil phase (Smix/oil) and ratio of surfactants to co-surfactant (S/Cs) on skin flux were also evaluated.
Skin flux was increased when S/Cs and Smix/oil were decreased, and HLB was increased. Optimized formulation was obtained as: HLB=8, S/Cs=3 and Smix/oil=5.4, with average particle size of 69 nm. The optimized nano/submicron emulsions increased desmopressin skin flux 4.45 fold relative to drug solution. Skin flux was increased when S/Cs and Smix/oil were decreased, and HLB was increased. Optimized formulation was obtained as: HLB=8, S/Cs=3 and Smix/oil=5.4, with average particle size of 69 nm. The optimized nano/submicron emulsions increased desmopressin skin flux 4.45 fold relative to drug solution.