| Tulobuterol is a long-acting ?2-adrenergic agonist,has been wildly used in form of transdermal patch clinically.Nowadays,tulobuterol patch has been used extensively in the long-term management of asthma and chronic obstructive pulmonary disease(COPD)to relieve symptoms of dyspnea,with good clinical effectiveness and safety.The development of children's tulobuterol patches has attracted the attention of clinicians.In order to understand the release characteristics of children's tulobuterol patches made by different formulations and preparations,this paper has established a high efficiency,sensitive and accuracy method for the determination of tulobuterol in New Zealand rabbit plasma,and has also provided analytical tools for formulation development and preparation optimization.First,a sensitive and simple ultra-high-performance liquid chromatography/tandem mass spectrometry(UHPLC-MS/MS)method was developed to determine the concentration of tulobuterol in New Zealand rabbit plasma.The method was validated with good linearity over the range of 0.01-6 ng/mL for tulobuterol(r>0.999).The lower limit of quantification value of tulobuterol(LLOQ)was 0.01 ng/mL.Carryover of tulobuterol and IS were 6.1%and 0.31%respectively.The intra-and inter-day accuracies of 4 concentration level QC(LOQ?LQC?MQC and HQC)samples were 95.0-111%and 94.6-110%,respectively,and the precisions were within 6.9%.The recoveries of tulobuterol were between 80.9-85.3%and the matrix effects normalized by IS were 92.2-109%.Stability studies included untreated samples in room temperature for 6h,-80?for 2 months,three freeze-thaw cycles at-80? and treated samples at autosampler temperature for 24h,and the accuracy of tulobuterol were all within the range of 94.1-113%.The method validation results were in accordance with the requirements of the Chinese Pharmacopoeia "9012 Guidelines for the validation of Quantitative Analysis Methods for Biological Samples",and all data and results showed that this method was suitable for the reliable quantitative determination of tulobuterol in New Zealand rabbit plasma.Then,the established UHPLC-MS/MS method was successfully used to determine the concentration of tulobuterol in rabbit plasma samples after the administration of Tulobuterol patches.Further,the relevant pharmacokinetic parameters were calculated,and the transdermal absorption characteristics were investigated.A total of two administration New Zealand rabbit groups were set up,including a reference preparation group and a test preparation group.The experimental results showed that the AUC(0-t)and AUC(0-?)were equivalent between the two batches with the ratio value 85.9-113.9%within the 90%confidence interval,but the Cmax was not equivalent within the 90%confidence interval with the ratio value 21.0-140%,out of the limitation of 85-125%.It indicated that transdermal absorption characteristics of the test preparation was different from the reference preparation,and the formulations and preparations needed to be further optimized.Tripterygiun glycosides tablets(TGT),derived from the extract of traditional Chinese medicine Tripterygium wilfordii(Tripterygium wilfordii Hook.f.),were widely used in the treatment of autoimmune diseases such as rheumatoid arthritis,nephrotic syndrome and lupus erythematosus.However,the toxic reactions caused by TGT could not be ignored,especially in liver and kidney.The study on the materia basis and mechanism of the effectiveness and toxicity of TGT has become a hot topic.In this paper,the metabolites of TGT in mice were studied.First,BALB/c mice were divided into three groups:single high-dose(LD50 dose,900 mg/kg)group,single low-dose(therapeutic dose,15 mg/kg)group,and multiple(7 days)low-dose group.After administration,liver,kidney and plasma samples of mice were taken.Then,the HPLC-QTOF-MS method established in our laboratory was used to analyze the prototype components and metabolites of TGT in mice.The components and metabolites were speculated and identified based on their retention time,accurate mass data of quasi-molecular ion,characteristic fragment ions,and the fragmentation rules,as well as comparing with reference standards and literature data.As a result,a total of 48 prototype components and 99 metabolites of TGT were detected in single high-dose group,15 components and 7 metabolites in single low-dose group,and 32 components and 16 metabolites in multiple low-dose group,respectively.Finally,prototype components and metabolites structures were drawn and compounds hepatotoxicity were predicted by Discovery StudionTM software.Consequently,a total of 21 prototype components and 35 metabolites were predicted to have potential hepatotoxicity in single high-dose group,6 prototype components and 3 metabolites in single low-dose group,13 prototype components and 5 metabolites in multiple low-dose group.In summary,there were six common potential toxic components among three groups.By studying the potential hepatotoxicity of the exposed components of TGT in vivo,potential toxic components and metabolites could be early monitored to discover toxicity trends.Comparing to single low-dose group,multiple dose showed a tendency to accumulate ingredients and indicated to take care of the medication cycle. |
PDF Full Text Request