Comparison of the brain pharmacokinetics of nasal tetramethylpyrazine phosphate pH-sensitive in situ gel in normal rats and model rats / 药学学报

The study is to investigate the brain pharmacokinetics change of nasal tetramethylpyrazine phosphate (TMPP) pH-sensitive in situ gel in normal and model rats. Acute cerebral ischemia rat model was successfully established by middle cerebral artery occlusion (MCAO) method. Both normal and model rats were given nasal TMPP pH-sensitive in situ gel (10 mg x kg(-1)). Perfusates of brain striatum area were collected at each time point by microdialysis. The content of TMPP was determined by HPLC. The pharmacokinetics parameters were calculated by Kinetica 4.4 software at each time point of the brain drug concentration. The main pharmacokinetics parameters of TMPP were fitted with compartments 2. After nasal TMPP pH-sensitive in situ gel the values of C(max) and AUC of both components in brain showed as follows: the value of model group > that of normal group. Significant difference can be observed in the process of brain pharmacokinetics in normal and model rats after giving nasal TMPP pH-sensitive in situ gel.

Bioequivalence study of sinomenine patch by microdialysis / 中国中药杂志

<p><b>OBJECTIVE</b>To study bioequivalence of Sinomenine patch made by different preparation process, and to testify feasibility and superiority of microdialysis as a new method in topical bioequivalence study.</p><p><b>METHOD</b>Normal gel patch and liposome gel patch of sinomenine were prepared by different preparation, nude mouse served as the experimental subjects sampling method of drug in the skin was tissue homogenization microdialysis, and drug concentration in dialysate was determined by HPLC.</p><p><b>RESULT</b>Results of tissue homogenization showed that liposome gel patch leads more remainder drug in the skin of nude mouse than normal gel patch, and results of microdialysis showed that liposome gel patch led higher instantaneous drug concentration than normal gel patch. Concentration-time curve of sinomenine in the skin accorded with the results of most dermal delivery systems studies over the world.</p><p><b>CONCLUSION</b>Topical bioequivalence of liposome gel patch of sinomenine is higher than that of normal gel patch of sinomenine. Microdialysis can be used to study bioavailability and bioequivalence of different preparation.</p>

Determination in vitro of rat plasma protein binding rate of sinomenine by using microdialysis method / 药学学报

<p><b>AIM</b>To determine in vitro the rat plasma protein binding rate by using microdialysis method.</p><p><b>METHODS</b>The binding rate was determined by using microdialysis probe as sampling tools and zero-net flux method as calibrating method. The regression equation was made by the difference of concentrations between the dialysis sample and the perfusate. The x-intercept of regression equation was the free drug concentration (Cf). The plasma protein binding rate was calculated by using the following equation: f = ( C0 - Cf)/C0.</p><p><b>RESULT</b>The binding rate was kept relatively stable in the studied concentration range.</p><p><b>CONCLUSION</b>It is feasible that the plasma protein binding rate can be determined by using microdialysis method.</p>

Study on determination of entrapment efficiency of sinomenine liposomes / 中国中药杂志

<p><b>OBJECTIVE</b>To establish an HPLC method for the determination of entrapment efficiency of sinomenine liposomes.</p><p><b>METHOD</b>The liposomes and dissociated drugs were separated by sephadex filtration, mini-column centrifugation and dialysis. The methodology study and the optimization of determining condition were carried out at the same time.</p><p><b>RESULT</b>Sephadex filtration could effectively separate the sinomenine liposomes from dissociated sinomenine. The column recovery was 98.8%, the average entrapment efficiency of three tests was64.9%, RSD 2.67%.</p><p><b>CONCLUSION</b>The method was simple, exact, and had a good reappearance. It can be used to examine the entrapment efficiency of sinomenine liposomes.</p>

A study on the percutaneous penetration of artesunate from various reservoir vehicles / 中国中药杂志

<p><b>OBJECTIVE</b>To determine the main factors which affect the percutaneous penetration of artesunate and provide efficient data for the artesunate transdermal delivery system.</p><p><b>METHOD</b>Transdermal speed constant and accumulative amount of 12 hours were used for the estimations of various reservior vehicles, and the supplement orthodox design was used to study the effect of pH, various proportion of IPA/Water/IPM, and drug concentration.</p><p><b>RESULT</b>Drug concentration and pH were the main factors which affected the percutaneous penetration of artesunate.</p><p><b>CONCLUSION</b>The suitable reservior vehicle can prompt the percutaneous penetration of artesunate, and artesunate TTS will be made with further studies.</p>