HEPARINS 
Heparin is a naturally occurring, complex glycosaminoglycan that has anticoagulant activity and has been used for decades as an antitrombotic agent in management of patients at high risk for thromboses.  Heparin is synthesized in mast cells as a polymer from glucuronic acid and glucosamine residues, 10 to 15 of which are attached to a core protein resulting in a large proteoglycan of 750,000 to 1,000,000 daltons.  This complex is then modified extensively and then degraded into glycosaminoglycan chains of 5000 to 30,000 daltons.  Heparin for therapeutic use in humans is generally made from extracts of bovine lung or porcine intestinal mucosa and consists of a heterogeneous mixture of glycosaminoglycans of slightly different structures and molecular weights.  Commercial preparations of heparin are standardized as USP units/mg.
Low molecular weight heparins (1000 to 10,000 daltons) are isolated from standard heparin preparations, which are then partially depolymerized and purified by gel chromatography and alcohol precipitation.  Commercial preparations of low molecular weight heparins are standardized in a bioassay based upon inhibition of coagulation factor Xa.  Heparin is a large glycosaminoglycan and is not absorbed through the gastrointestinal mucosa and must be given intravenously or by subcutaneous injection.  Heparin is used as the initial treatment of venous thrombosis and pulmonary embolism because of its rapid onset of action, while awaiting the slower onset of activity of oral anticoagulants (such as warfarin).  Heparin is also used in the setting of acute myocardial infarction and unstable angina and in prophylaxis of venous thrombosis during and/or after surgery.  In addition, heparin is used to maintain potency of intravenous indwelling catheters (“heparin lock”), usually in low doses (10 to 100 units), and is not meant for therapeutic purposes.  Recently, low molecular weight heparins have replaced standard heparin in many situations, their advantage being a more predictable pharmacokinetics which allows for subcutaneous administration and outpatient management.

SODIUM HEPARIN
CALCIUM HEPARIN
HEPARINOIDS
HEPARINOIDS JPC.
HEPARAN SULFATE