Preparation And Evaluation Of Tetramethylpyrazine Phosphate Cataplasm

Tetramethylpyrazine phosphate?TMPP?is a novel calcium channel blocker,which can inhibit free radicals,increase cerebral blood flow,and improve blood viscosity.It is widely used in the treatment of cardiovascular and cerebrovascular diseases.At present,the clinical dosage forms are mainly tablets and injections.The first-pass effect of the tablets is obvious,the injection is more irritating,the patient has poor compliance,and the long-term medication has large side effects.Cataplasm can avoid the first pass effect of the liver,the drug loading is large,the water content is high,and there is no allergic reaction.In order to better play the clinical role of TMPP and reduce adverse reactions,TMPP was made into cataplasm and evalued in this study.ObjectiveIn this study,the basic physical and chemical properties of TMPP were investigated to predict the percutaneous permeability of TMPP.The prescription of cataplasm matrix was optimized and TMPP cataplasm was prepared.The quality of TMPP cataplasm was preliminarily evaluated,and the pharmacokinetic study and in vitro/in vivo correlation investigation were further carried out,which provided some reference for the development of TMPP transdermal preparations.Methods1.The equilibrium solubility and oil-water partition coefficient of TMPP in different media at 32°C were investigated and to explore whether TMPP has the potential to be developed into transdermal preparations.2.Through the preliminary literature research and related experiments,the cataplasm matrix components were initially screened.On the basis of single factor test,water content,adhesion,membrane residue and peel strength were used as comprehensive evaluation indicators.Partial factor test were used to screen out the significant factors affecting matrix performance,and the Box-Behnken effect surface method was used to further optimize the prescription.On this basis,TMPP cataplasm was developed.3.According to the quality standards of the four editions of the Chinese Pharmacopoeia in 2015,the properties,paste content,the adhesion,the shaping properties and weight difference were examined.The high performance liquid chromatography?HPLC?method was used to determine the content and the methodological investigation was carried out.4.The transdermal experiment in vitro of the self-made TMPP cataplasm was carried out.The model was fitted and the transdermal permeation rate was calculated.The transdermal permeation curve was drawn.5.Taking the shape and initial adhesion as evaluation indexes,the influencing factors of the self-made TMPP gel paste were investigated to determine the influence of high temperature,high humidity and light on TMPP cataplasm.6.Rats were randomly divided into cataplasm group,oral administration group and intravenous injection group.HPLC analysis method was established to determine the blood concentration in rats and the methodological investigation was carried out.The main pharmacokinetic parameters of the three drug delivery routes were calculated using the non-compartment model statistical moment in DAS 3.0 software.SPSS 21.0statistical software was used for data processing analysis.The concentration-time curve was drawn and the bioavailability was calculated.7.The in vitro/in vivo correlation of TMPP cataplasm was analyzed by the deconvolution.Results1.At 32°C,TMPP had the highest solubility in water,it was 26.19 mg/mL,followed by physiological saline,it was 25.63 mg/mL.In the range of pH 4.5⁸.0,the solubility of TMPP decreased with the increase of pH value.The LogP values measured by TMPP in different media were all greater than 1,and the oil-water partition coefficient of TMPP increased with the increase of pH as a whole,and changeed slightly in the range of pH 5.8⁸.0.The results indicated that TMPP was suitable for development into a transdermal formulation.2.The matrix components of the cataplasm were initially selected as:sodium polyacrylate?NP-700?as the matrix material,carbomer 940 as the excipient,polyvinylpyrrolidone?PVP K30?as the binder,and galaluminate as the crosslinking agent.Glycerin was a humectant,tartaric acid and disodium edetate?EDTA-2Na?were crosslinking regulators.The results of partial factor test showed that carbomer,glycerol and NP-700 had the most significant effects on the matrix.The optimal formulation of blank matrix by Box-Behnken effect surface method was:carbomer 5 g,glycerol 15.20mL,EDTA-2Na 0.037 g,galaluminum 0.055 g,sodium polyacrylate 3.46 g,tartaric acid0.054 g,PVP K30 1.98 g.To ensure better skin compatibility and adhesion,the dosage of glycerol and NP-700 was adjusted to 15.32 mL and 3.56 g,respectively.The composition of TMPP gel paste was:TMPP 2.172 g,carbomer 5 g,EDTA-2Na 0.037 g,hydroxyaluminum 0.055 g,NP-700 3.56 g,glycerol 15.32 mL,PVP K30 1.98 g,tartaric acid 0.054 g,water 112.6 g.3.The preliminary quality inspection results of TMPP cataplasm showed that the homemade TMPP cataplasm was a white transparent viscous semi-solid preparation;the three batches of cataplasm contained a paste amount between 19.91 and 20.55 g/100cm²,so the paste content was set to be not lower than 19 g/100 cm²;Three batches of gel paste could stick to the 22nd steel ball,so the initial adhesion was set to at least stick to the 22nd steel ball;The cataplasm did not fall on the test plate for 24 h,indicating that the adhesive strength was good;the average weight of 10 tablets of TMPP cataplasm was 5.19 g,and the RSD was 1.41%;HPLC method validation showed that the method can accurately determine TMPP.The content of the three batches of TMPP cataplasm was between 90%and 110%.4.The TMPP in vitro transdermal process conformed to the zero-order kinetic model,which indicated that TMPP was transdermally diffused at a constant rate.The permeation rate equation was Q_n=65.192t-15.583?R²=0.9974?and the transdermal rate was 65.192?g?cm^-2?h^-1.The cumulative permeation amount of TMPP was 1155.721?g for 12 h.5.Influential factors test showed that TMPP cataplasm had no obvious change in appearance and initial adhesion under high humidity and light conditions.Under high temperature conditions,the paste dried slightly and appeared slightly shrunken,and the initial adhesion was reduced,which indicated that high temperature should be avoided during storage.6.The pharmacokinetic HPLC methodological results showed that the method hadhigh specificity and good precision,and the method recovery rate and extraction recovery rate met the analytical requirements.The main pharmacokinetic parameters of each group are as follows:cataplasm group AUC_0-t:100.234?15.239?g?mL^-1?h,C_max:17.026?5.796?g/mL,T_max:4.333?0.516 h,t_1/2:6.594?3.631 h;Oral administration group AUC_0-t:70.194?38.315?g?mL^-1?h,C_max:40.41?14.711?g/mL,T_max:0.514?0.318 h,t_1/2:0.763?0.239 h;Intravenous group AUC_0-t:37.946?17.266?g?mL^-1?h,C_max:55.223?15.453?g/mL,t_1/2:1.607?1.664 h.There were significant differences in the main pharmacokinetic parameters between the cataplasm and the oral administration group and the intravenous injection group?p<0.05?.The relative bioavailability and absolute bioavailability of TMPP were 18.0%and 10.1%,respectively.7.In vitro/in vivo correlation results showed that the regression equation of the cumulative cumulative release?Q'%?in vitro and the ratio of AUC to AUC_last?R?was y=0.9143x-0.0273?r=0.974?,and when the degree of freedom was 4,the critical value was 0.917,and the correlation coefficient r>r_4,0.01,0.01 of the regression equation,which indicated that TMPP cataplasm had a good correlation with transdermal absorption in vivo.ConclusionThis study clarified that TMPP was suitable for development into transdermal preparations.The preliminary development of TMPP cataplasm had good pharmacy performance and a certain sustained release effect.It laid the experimental foundation for the development of TMPP into cataplasm and provided a new route of administration for the clinical indications of TMPP.