Blood Release Of Enoxaparin Sodium From Bone Cement In The Model Of Hip Replacement In Rabbits

[Objective] to observe the concentration and time variation of blood release of enoxaparin sodium in the bone cement with different proportion in the hip replacement model of rabbits under physiological environment.[Methods] 1.Experimental group: 15 healthy New Zealand white rabbits with a body weight of about 2.5 ± 0.5kg were selected.The rabbits were evenly divided into A,B,C groups using the random number method,and the three groups were cross-controlled with 5 rabbits in each group..The right hind limbs of the New Zealand white rabbits were selected as the experimental side.Before the experiment,the rabbits were raised separately in cages and in a quiet environment for one week to adapt to the environment.The experiment was started after the experimental animals were in a stable and normal state.2.The model of hip replacement was made by operation: the rabbits were anesthetized and maintained by intravenous injection of 25% urethan according to 0.5ml / kg at ear border.After the corneal reflex disappeared,the anesthesia was satisfactory.Sterilize the sheet,separate the muscle of the upper part of the femur,expose the greater trochanter and the distal femur,drill the lower part of the greater trochanter and the distal femur,to clean the medullary cavity with plenty of physiological saline.The enoxaparin sodium of 4000 axaiu,8000axaiu and 12000 axaiu were added into 40 g Palacos ? r PMMA bone cement respectively.2ml of bone cement of three different proportions were respectively injected into the femoral shaft medullary cavity of three groups of rabbits by syringe,then the bone cement was compacted and stitched layer by layer.3.Collection and processing of experimental data: 15 rabbits were raised in cages after operation.Blood was collected from the ear vein of rabbits on day 1,day 2,day 3,day 4,day 5,day 6 and day 7 respectively.The content of enoxaparin sodium in blood was determined by developing substrate method.[results] all the experimental animals survived to the end of the experiment.In our rabbit hip replacement model,the release effect of enoxaparin sodium in vivo was similar to that in vitro.On the first day,the release potency of enoxaparin sodium reached a peak After 7 days,the release potency of drug plasma began to decline,and the release potency of some drugs was lower than the sensitivity of the measurement method.After bone cement with different concentration of enoxaparin sodium was implanted into the medullary cavity of femoral shaft of rabbits,the titer of enoxaparin sodium measured in blood was different between groups(P < 0.05).[Conclusion] the release potency of enoxaparin sodium bone cement in the hip replacement model of rabbits peaked on the first day after operation,and decreased continuously within one week.In the whole experimental process,the release of enoxaparin was much lower than that of enoxaparin in the effective prevention of thrombus.On the first day and after that,it will not have a significant impact on the systemic coagulation system,the systemic blood concentration is within the safe range,and it will not have a significant impact on the postoperative routine thrombo prophylaxis means of hypodermic injection of low-molecular-weight heparin sodium.