| Objective To prepare PNS-TFSs with enhanced therapeutic effect on local acute soft tissue injury.To clarify the above characteristic by vehicle characterization,in vitro tests of percutaneous permeation and skin deposition and in vivo test of pharmacodynamics.Methods The HPLC method was adopted to determine the content of the main ingredients of PNS in the PNS-TFSs.The PNS-TFSs were prepared by thin film hydration method.On the basis of single factor experiments on the drug-to-lipid ratio,formulated quality of volatile oil and CH,pH and ionic concentration of hydration liquid,the formulation of PNS-TFSs were further optimized by a uniform design experiment.Morphology of the PNS-TFSs was observed by transmission electron microscope,mean particle size,PDI and Zeta potential were determined by laser scattering particle size analyzer,elasticity of the bilayers was evaluated by extrusion method and entrapment efficiency of PNS-TFSs were determined by centrifugation-ultrafiltration method.The excised skin was prepared from Sprague Dawley(SD)male rats.The skin permeation and deposition tests of PNS-TFSs were carried out with a Franz diffusion cell fitted with excised rat skin with the PNS-LPSs being used as reference.The model of acute soft tissue injury in rats was established by the method of quantitative heavy object hammering.The therapeutic effects of the PNS-TFSs were evaluated by observing the indexes of injury symptom,the blood viscosity,the inflammatory mediators and the histomorphology with the "shangtong-ning" plaster,the PNS-LPSs and the blank-TFSs being used as positive control,negative control and blank control respectively.Results The concentration(within the range examined)of R1,Rg1,Re and Rb1 in PNS has good linear relationships with their peak area,reapectively,and the specificity,precision,recovery and stability of the analysis method comforms to the requirements.Based on single factor experiments and uniform design experiment,an optimum formulation were as follows:PNS 100 mg,CH 30 mg,sbPC 120 mg,VE 2 mg,volatile oils(limonene:citral=4:1)80 mg,hydration liquid(A phosphate buffered saline with pH at 5.0 was constituted by mixing 1/15 mol·L-1 potassium dihydrogen phosphate solution with 1/15 mol·L-1 disodium hydrogen phosphate solution according to a suitable proportion and followed by a 10-folds dilution with distilled water)10 mL.The optimized PNS-TFSs were round to roundish vesicles,had an average size of(83.84±3.47)nm,a PDI of(0.088±0.018),a Zeta potential of(-25.6±0.56)mV,an elasticity of(2.62±0.15)min and entrapment efficiencies of(74.81±1.54)%,(85.58±1.17)%for Rg1 and Rb1 respectively.The in vitro skin permeation experiment showed that the PNS in the optimized PNS-TFSs could quickly penetrate the skin(the accumulated skin penetration amount of R1,Rg1,Re and Rb1 with the optimized PNS-TFSs was about 3,2.5,3,3.5 times of that with the PNS-LPSs respectively,after 36 h).The in vitro skin deposition experiment showed that the deposition amount of PNS in PNS-LPSs was more than that in the optimized PNS-TFSs on the whole,but the deposition amount of PNS in PNS-LPSs and the optimized PNS-TFSs was different in different time periods,and it also has certain differences between different ingredients.The results of pharmacodynamical tests showed,that the PNS-TFSs could significantly improve the indexes of injury symptom,the level of inflammatory mediators,the blood viscocity and the histomorphology of the rats.And it has obvious superiority compared with blank control and negative control groups.Conclusion The thin film hydration method is reliable for the preparation of PNS-TFSs and the process has a good reproducibility.The optimized PNS-TFSs have good skin permeability.And the results of pharmacodynamical tests showed that the PNS-TFSs have a definite curative effect for acute soft tissue injury in rats. |
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