LMWHs are a diverse group of chemically distinct compounds. Most are prepared by various chemical or physical depolymerisation techniques; others, such as tinzaparin, are produced by enzymatic depolymerisation [40].
Clexane® is obtained by chemical β elimination of the benzyl ester of heparin derived from porcine intestinal mucosa. Each LMWH is manufactured using a slightly different method, conferring unique properties on each product. As a result of these differences in manufacturing techniques, the available products differ markedly in terms of their mean molecular weights, mix of polysaccharide chain lengths, and pharmacological properties [40].
Figure: different methods of LMWH preparation result in distinct chemical structures [41]
| Enoxaparin | Tinzaparin | |
|---|---|---|
| Brand name | Clexane | |
| Manufacturing process | Benzylation followed by alkaline hydrolysis | Heparinase digestion |
| Mean molecular weight (daltons) | 4500 | 6500 |
| Elimination half-life (hours) | 4.5 | 3.4 |
| Bioavailability (%) | 90–92 | 87 |
| Anti-Xa/anti-IIa ratio | 3.8 | 2.8 |
| Anti-Xa activity (IU/mg) | 100 | 100 |
