| Objective:Radix Linderae is the dry root of Lindera aggregate?Sims?Kostem.Norisoboldine hydrochloride?NOR·HCl?is the main isoquinoline alkaloid in the radix of traditional Chinese medicine Radix Linderae,which has anti-rheumatoid arthritis effect.However,after oral administration and intravenous injection of NOR·HCl,the rapid metabolism in vivo limits the application.In this study,NOR·HCl was made into microemulsion to improve the percutaneous permeability of the drug,and then added the carbomer to make the microemulsion gel.It's convenient and sate for administration,prolonged the retention time of the drug in the skin,and compared with the commonly used cream in the transdermal permeability,the stability,vitro release,in vivo microdialysis,pharmacodynamics in rats.Methods:The basic properties of NOR·HCl detection method and oil-water partition coefficient were investigated by high performance liquid chromatography.Preparation of microemulsion gel:The solubility of NOR·HCl in excipients was determined,and the oil phase,surfactant and cosurfactant were screened according to the size of microemulsion area in pseudo-ternary phase diagram.Then effects of the proportion of oil phase,mixed surfactant and water phase in microemulsion on particle size and transdermal rate were investigated by single factor.The best prescription proportion of microemulsion was optimized by response surface methodology,and particle size,structure type and morphology were characterized.The matrix,concentration and preparation method of the microemulsion gel were selected,and the microscopic morphology was characterized.Preparation of cream:According to the appearance state,centrifugation and high and low temperature stability as indicators,select the appropriate cream base prescription.And orthogonal experiment was designed to determined the preparation time,temperature and stirring rate.The following comparative studies were carried out on microemulsion gel and cream:The influence factors under high temperature,high humidity and strong light were investigated.In vitro release was determined by Dialysis bag method for 48 h.Franz diffusion cells were used to investigate percutaneous permeability in vitro.In vivo microdialysis was used to investigate the transdermal properties of rats.Rats were given local administration after abdominal depilation.The receiving solution was collected by microdialysis technique and the drug concentration was determined by UPLC-MS/MS.The drug concentration-time curve was examined respectively.The pharmacodynamics of rheumatoid arthritis in rats was studied to investigate the changes of swelling degree and inflammatory of the feet after administration.Results:Determination of HPLC content of NOR·HCl:mobile phase A was acetonitrile,B was 0.5%formic acid and 0.1%triethylamine solution,0?13 min,10%?22%A,13?22 min,22%A;the flow rate was 1 m L·min-1;the detection wavelength was 280 nm;the column temperature was 30?;the injection volume was 5?L;NOR·HCl was linear within 10.3?1030.0?g/m L,the correlation coefficient r=0.9999,all methodological investigations are consistent Claim.Preparation of microemulsion gel:45.24%Labrafil M 1944 CS?oil phase?,15.39%lecithin?surfactant?and 30.78%ethanol?cosurfactant?were mixed and dissolved evenly into transparent solution,8.59%water was added one by one at the stirring rate of 600 rpm,the blank microemulsion was prepared by stirring equilibrium for 60minutes.Then added NOR·HCl 25 mg/m L into the microemulsion.The NOR·HCl microemulsion with particle size of 51.11+2.21 nm was obtained by Malvern laser particle size analyzer.The results of transmission electron microscopy showed that the microemulsion droplets were spherical like,with good formability and regular morphology.The preparation of microemulsion gel was finally verified as:adding 1.5%carbomer 940 into the NOR·HCl microemulsion and stirring 24 h,the microemulsion gel was obtained after adjust p H 6 to 7,which was light yellow semisolid.Transmission electron microscopy showed that microemulsion still could retain the microstructure of the NOR·HCl microemulsion.The optimized preparation of NOR·HCl cream was verified as:the oil phase was consisted of 0.5 g paraffin,2.5 g white vaseline,6.25 g liquid paraffin,3 g glycerol monostearate,0.5 g Span 80 and 0.75 g octadecanol.The aqueous phase was consisted of 0.25 g Tween 80,0.02 g Ethyl 4-hydroxybenzoateand and 11.22 g water.NOR·HCl was dissolved in the water phase,then oil phase was slowly dripped into the water phase at 80?,and kept the stirring speed of 700 rpm to balance fully.NOR·HCl cream is obtained after condensation.The experiment of influencing factors showed that the oil-water separation occurred in the cream under high temperature,the content of NOR·HCl in each preparation increased obviously under the high humidity condition,and the color of each preparation was deepened by strong light,so it should be stored at room temperature under the condition of sealing and avoiding light.In vitro release,the results of showed that NOR·HCl saline solution was almost completely released for 4 h,and the release time of cream,microemulsion and microemulsion gel was 24 h,48 h,48 h respectively,indicated that each preparation had a good sustained release effect.The in vitro release equation showed that the release mechanism of NOR·HCl saline solution,cream and microemulsion was diffusion,and the release mechanism of microemulsion gel was the synergistic effect of diffusion and dissolution.The in vitro penetration rate of saline,cream,microemulsion and microemulsion gel were 0.8907?6.5001?74.206?13.003?g·cm-2·h-1,the results showed that the cream,microemulsion and microemulsion gel had obvious penetration promoting effect,especially the microemulsion.In the study of in vivo microdialysis,the AUC of NOR·HCl saline solution,cream and microemulsion gel were?88.20±1.45???511.17±4.78???1221.33±218.92???1492.68±265.75?ng·h·m L-1respectively,it showed that both cream,microemulsion and microemulsion gel had obvious penetration promoting effect,especially microemulsion and microemulsion gel.In the model of rheumatoid arthritis induced by collagen,the feet of rats were obviously swollen.After administration 20 days,the swelling rate of toe and inflammatory factors such as IL-1?,IL-6 and TNF-?in cream,microemulsion and microemulsion gel was significantly different from that in the model group.The results showed that NOR·HCl microemulsion,microemulsion gel and cream could inhibit inflammatory factors and had a good inhibitory effect on rat foot swelling.Conclusion:In this study,NOR·HCl microemulsion gel and cream were prepared successfully.Both of them have sustained-release effect.They can increase the retention time of NOR·HCl and increase the transdermal permeation rate and cumulative transdermal volume.It can significantly inhibit the swelling of the foot and the level of inflammatory factors in rats with rheumatoid arthritis. |
PDF Full Text Request