Experimental Study On Drug Release Concentration Of Enoxaparin Sodium Polymethylmethacrylate Cement

Objective: To investigate the release characteristics of enoxaparin sodium polymethyl methacrylate(es-pmma)bone cement in animals and the sustained release concentration of enoxaparin sodium after operation.Methods: Twenty rabbits were randomly divided into four groups: A,B,C and D.In the control group A,enoxaparin sodium was not added.In the experimental group B,C and D,the amount of enoxaparin sodium(ES)added for every 40g bone cement was 4000,8000 and 12000 axaiu respectively.The test pieces were placed in the right femoral marrow cavity of New Zealand male rabbits,bound with non absorbable suture,and the drainage fluid was collected by a built-in negative pressure drainage tube.The concentration of enoxaparin sodium in the drainage fluid was measured in the experimental group for 10 consecutive days,and the data were analyzed by statistical analysis.P <0.05 was considered statistically significant.Standard solutions of different drug concentrations were mixed with the same volume of rabbit plasma,and the absorbance of each tube was measured by the microchromogenic substrate method and ultraviolet-visible spectrophotometer.The drug concentration of the drug-containing plasma solution was C(U/ml)as the abscissa,Absorption(A)is the ordinate,linear regression is performed,and a linear equation is obtained.Results: 1.Taking the drug concentration C(U/ml)of the rabbit-containing plasma solution as the abscissa and the absorbance(A)as the ordinate,the linear relationship is good.The linear regression equation is: A =-0.204C+1.022.2.All animals were kept alive until the end of the experiment.ES-PMMA bone cement with different ES drug loadings reached the highest ES release concentration in New Zea land white rabbits after 24 hours in vivo.The experimental groups B,C,and D were 0.713±0.23 U/ml,1.157±0.27 U/ml,1.662±0.16 U/ml,after which the concentration release gradually decays.Conclusions: ES-P MMA bone cement specimens can be released locally after implantation in New Zealand rabbits,exerting local anticoagulant effect.