Lecithin vesicular carriers for transdermal delivery of XXXX .

@entity658 @entity205 @entity19 @entity5222
Two kinds of @entity5222 with and without the presence of @entity658 (flexible @entity5222 and conventional @entity5222 ) were prepared, using @entity205 as model drug. When applied onto the excised abdominal skin of @entity19 non-occlusively, the enhancing effects of @entity5222 on the penetration of @entity205 were assessed by an in vitro permeation technique. The effect of @entity658 micelles was also studied. In vivo study was carried out by topical application of @entity5222 onto the @entity19 skin and drug serum concentration was detected. Results showed that after 8 h of administration, flexible @entity5222 transported 1.16 microg of @entity205 through per cm(2) @entity19 skin and amounted to 1.88 microg 24 h later. The residual amount in the skin was 1.78+/-0.51 microg/cm(2). However, flexible @entity5222 failed to transport measurable amount of drug through pre-hydrated skin while deposited 2.39+/-0.26 microg/cm(2) into the skin. Conventional @entity5222 failed to transfer @entity205 into the receiver while accumulated 0. 72+/-0.19 microg/cm(2) of drug in the skin. Furthermore, 1 and 40% @entity658 micelles precluded the transport of @entity205 . In vivo studies indicated that with the application of flexible @entity5222 , serum drug concentration of 53.43+/-9.24 ng/ml was detected 2 h later. After the stratum corneum of @entity19 skin has been destroyed by shaving, flexible @entity5222 transferred large amount of drug into blood, up to 187.32+/-53.21 ng/ml after 1 h of application. Conventional @entity5222 failed to deliver measurable amount of drug into the blood under normal skin condition. In conclusion, flexible @entity5222 is better than conventional @entity5222 as the carrier for transdermal delivery of @entity205 . Penetration and fusion have been suggested to be two major functional mechanisms. Hydration is detrimental to the enhancement effect. Stratum corneum constitutes main barrier to the transport of lipophilic @entity205 .
