Anticoagulant profiling of a Generic Enoxaparin and its comparison with its Branded version

Abstract

INTRODUCTIONLow Molecular Weight Heparins (LMWHs) have been used parallel to Unfractionated Heparin (UFH) for the prophylaxis and treatment of venous thrombosis. Currently, the resourcing of LMWHs includes bovine (BE), ovine (OE) and porcine mucosal (PE) tissues. The relative potency of these drugs not only depends upon the inherent properties of the particular drug but also depends on the type of assays used. In our study we compared the potencies calculated from different anticoagulant/anti‐protease methods for Generic LMWHs with Branded LMWH.MATERIAL AND METHODSFour Generic LMWHs prepared from the porcine heparin of US origin and one Branded LMWH were compared. Blood was drawn from healthy volunteers (n=5) and supplemented with each of the individual LMWHs to obtain final concentrations of 10‐0 ug/mL. These samples were analyzed for anticoagulant assays: aPTT (2 reagents) and Thrombin Time (TT) assays immediately on ST4 instrument. The remaining blood was centrifuged (3000rpm, room temperature for 20minutes) for retrieved plasma. The retrieved plasma samples were analyzed for assays: aPTT (2 reagents), TT, Anti‐Xa and Anti‐IIa on ACL elite instrument. The results were tabulated, potencies were calculated and graphed were made accordingly.RESULTSIn whole Blood system; in the aPTT (TriniClot), Branded LMWH had 80.8‐44.1 seconds (secs) and Generic LMWHs had 75.3±2.7 to 43.7±3.1 secs. In the aPTT (Actin FSL), Branded LMWH had 151.6‐65.8 secs and Generic LMWHs had 88.9±5.3 to 46.8±0.8 secs. In the TT, Branded LMWH had 183.3‐15.1 secs and Generic LMWHs had 140±31.6 to 18.9±3.1 secs.In retrieved plasma system; aPTT (TriniClot), Branded LMWH had 105‐29.5 secs and Generic LMWHs had 69±3.2 to 26.3±0.4 secs. On aPTT (Actin FSL), Branded LMWH had 224.3‐53.1 secs and Generic LMWHs had 119.5±11.4 to 37.4±0.3 secs. On TT, Branded LMWH had 300‐10.9 secs and Generic LMWHs had of 300±0.0 to 13.5±0.7 secs. On anti‐Xa assay, the % inhibition for Branded LMWH was 88.9‐20.1 % and Generic LMWHs had 74.9±1.5 to 15.2±2.6 %. While on anti‐IIa assay, the % inhibition for Branded LMWH was 90.3‐27.7 % and Generic LMWHs had 80.3±1.4 to 22.3±6.1 %.The USP potency calculated in whole Blood system from aPTT (TriniClot), Branded LMWH had 109 U/mg and Generic LMWHs had 106.1±5.4 U/mg, from aPTT (Actin FSL), Branded LMWH had 136 U/mg and Generic LMWHs had 95±5.0 U/mg. The potency calculated in retrieved plasma system from aPTT (TriniClot), Branded LMWH had 186 U/mg and Generic LMWHs had 110.3±4.6 U/mg, from aPTT (Actin FSL), Branded LMWH had 187 U/mg and Generic LMWHs had 108.8±3.9 U/mg. The AXa potency calculated for Branded LMWH was 132 U/mg and Generic LMWHs had 107.6±7.6 U/mg while AIIa potency calculated for Branded LMWH was 45 U/mg and Generic LMWHs had 35.8±2.0 U/mgCONCLUSIONThe results showed variable potencies for the four batches of Generic enoxaparin in different assays. Branded LMWH showed stronger response, suggesting that the depolymerization method used to obtain these LMWHs may differ and therefore effect their anticoagulant and anti‐protease activities. Furthermore, it was also noticed that all agents showed lower potencies on whole blood suggesting that binding/uptake of these drugs by the blood cellular components which maybe responsible for the decreased potencies. The remarkably higher potencies in the retrived plasmas for the branded enoxaparin may also be due to differential uptake and binding of the components by blood cells.