Title : Fabrication and characterization of transdermal patch loaded with Ascorbic acid
Ascorbic acid AA (vitamin C) has been widely used in the cosmetic field as an anti-wrinkle agent due to a variety of biological, pharmaceutical and dermatological functions. The main cause of aging is a decline in vitamin C content as a result of chronological aging and photoaging. The ability of AA to penetrate the skin is very low due to its physicochemical properties. AA is a water soluble vitamin (log p =-1.85), unstable and is not a potent drug. The aim of this study is to fabricate transdermal patch loaded with a high dose of a hydrophilic anti-aging compound (AA). The objective of using nnnanoemulsion as a vehicle in the present work is to overcome stability problems of AA since it can protect AA from degradation and promote an adequate penetration of AA into the skin for transdermal application. To the best of our knowledge, there have been no studies involving nanoemlusion loaded patch for transdermal delivery of AA. In order to fabricate patch with good mechanical properties to be used safely; number of biodegradable polymers were used. An optimized AA-loaded nanoemulsion containing 20% w/w oil phase, 60% w/w surfactant: cosurfactant and 20% water which passed visual tests for transparency, miscibility and ease of flow was selected, and then incorporated into the transdermal patch. Transdermal patches were prepared from 45% w/w hydroxypropyl methylcellulose (HPMC), 30% w/w carboxymethylcellulose sodium (NaCMC), 5% w/w polyethyleneglycol (PEG400) and 20% w/w AA-loaded nanoemulsion and then characterized for weight variation, stability and thickness. HPLC method for the quantification of AA was validated according to ICH guidelines. In addition, the in-vitro release of AA from these patches was determined using Franz diffusion cells. The patch with an area 1.76 cm2 was delivered 4 mg of AA in 24 h. Further formulations will be also studied.