Preparation of Sinomenine-loaded Hydrogel Ointment and Evaluation of Its Transdermal Performance in Vitro
Objective:In order to enhance the bioavailability of Sinomenine(Sin)for transdermal administration and improve its skin permeation properties,Sin-enriched hydrogel ointment was prepared by directly dispersing Sin into Carbomer 940(Cp940)matrix,and then the transdermal performances in vitro were investigated.Methods:Firstly,the amount of Cp940 and glycerol were used as the investigating factors,and the appearance shape,cumu-lative water loss and viscosity of the prepared ointment were used as the evaluation indexes to optimize the optimal prescription of the hydrogel ointment.Secondly,in vitro transdermal experiments with different permeation enhanc-ers using a modified Franz diffusion cell.Results:The results showed that the optimal formulation of the prepared hydrogel ointment was 1.5%Cp940,0.35%NaOH,10%ethanol,20%glycerol,0.2%sodium polyvinyl propi-onate,2%azidone,5%1,2-propanediol,2%drug,0.1%ethyl p-hydrobenzoate and appropriate amount of wa-ter.And the prepared hydrogel ointment was in the form of a yellow opaque semi-solid,which was stored at room temperature with no dry-out or liquefy.Meanwhile,ointment was easy to be spread and applied by administered transdermally on account of the suitable viscosity.The in vitro release experiments indicated that the best transder-mal penetration of Sin was achieved when azidone was combined with 1,2-propanediol as transdermal accelerators,as well as the Qn and cumulative release rate in 12 h were 347.12±3.84 μg·cm-2 and 22.8%,respectively,which could be identified as a zero-level release kinetic model.Conclusion:Therefore,the prepared Sin-enriched hydrogel ointment was expected to be a novel transdermal formulation for the effective treatment of rheumatoid ar-thritis.