Classifications

• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
  • A61K31/00—Medicinal preparations containing organic active ingredients
  • A61K31/70—Carbohydrates; Sugars; Derivatives thereof
  • A61K31/715—Polysaccharides, i.e. having more than five saccharide radicals attached to each other by glycosidic linkages; Derivatives thereof, e.g. ethers, esters
  • A61K31/726—Glycosaminoglycans, i.e. mucopolysaccharides
  • A61K31/727—Heparin; Heparan
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61P—SPECIFIC THERAPEUTIC ACTIVITY OF CHEMICAL COMPOUNDS OR MEDICINAL PREPARATIONS
  • A61P7/00—Drugs for disorders of the blood or the extracellular fluid
  • A61P7/02—Antithrombotic agents; Anticoagulants; Platelet aggregation inhibitors

Definitions

• the present invention relates to heparin-based compositions as well as their preparation process and their therapeutic applications.
• compositions based on heparins neutralized by protamine exhibiting antithrombotic activity but substantially devoid of hemorrhagic and anticoagulant activities.
• Heparin has been known and used for many decades for the preparation of drugs with antithrombotic and / or anticoagulant activity intended in particular for the preventive and curative treatment of venous and arterial thromboses or also to prevent the coagulation in the extra circulation bodily.
• heparin which are in particular contraindicated in patients predisposed to haemorrhage, patients suffering from duodenal or gastric ulcers or patients having undergone recent intervention. in which antithrombotic treatment with heparin can cause hemorrhages.
• the treatment uses protamine sulphate which causes the heparin to neutralize in vivo.
• the object of the invention is more precisely to eliminate as much as possible the risk of hemorrhage from heparins while retaining their main properties, in particular the antithrombotic activity.
• the object of the present invention is to provide heparin compositions which have very advantageous pharmacological properties, in particular antithrombotic, substantially equivalent to those of the heparins used hitherto, without having the major drawback which lies in the significant bleeding risk.
• Another object of the present invention is to provide a process for the preparation of such compositions which is simple to carry out and inexpensive, making it possible moreover to develop their therapeutic applications.
• the invention also relates to the therapeutic applications of these compositions.
• heparin compositions according to the invention which exhibit antithrombotic activity and are practically devoid of hemorrhagic activity. These compositions are characterized in that they essentially consist of heparin fractions as obtained by neutralization in vi- heparin by protamine.
• heparin fraction neutralized by protamine means any fraction originating from a native or already fractionated heparin, or from a synthetic heparin, the haemorrhagic power of which has been neutralized by the action of protamine or any analog or equivalent thereof having a similar ability to reduce hemorrhagic power.
• compositions according to the invention advantageously consist of heparin fractions as obtained by the in vitro neutralization of an unfractionated heparin or of a low molecular weight heparin with protamine.
• the composition consists of heparin fractions of which 25% have a molecular weight of less than 2.5 kDa and 40% have a molecular weight of more than 20 kDa,
• the composition consists only of heparin fractions having a molecular mass of less than 2.5 kDa.
• the heparin fractions have a spectrum of molecular weights depending on the protamine neutralization modes that are used.
• compositions according to the invention are substantially free of protamine.
• the invention also provides a process for the preparation of the above-mentioned compositions, characterized in that it comprises a step of in vitro neutralization of hepatic rine by protamine.
• the inventors have discovered that, surprisingly, it is possible to neutralize in vitro, in particular with the aid of protamine, the hemorrhagic activity of heparin while preserving its antithrombotic properties.
• the method according to the invention consists in reacting, in solution, a heparin with protamine, in particular in the form of the protamine salt, according to variable heparin / protamine ratios.
• a heparin solution is mixed with a protamine salt solution, preferably at room temperature, the mixture obtained is centrifuged and the supernatant is recovered.
• heparin solution is meant a solution of native or already fractionated heparin, or synthetic heparin.
• the protamine salt advantageously consists of protamine sulfate.
• any analog or equivalent of protamine having a similar capacity, neutralizing heparin and therefore reducing hemorrhagic power, can be used.
• the supernatant can then be lyophilized.
• the heparin to be treated and the protamine can be used in different reports which essentially lead to the elimination of the risk of haemorrhage linked to heparins.
• the method comprises the step of neutralizing a heparin with protamine or an equivalent, preferably in heparin / protamine proportions of 2/1 to 1/2.
• the heparin / protamine ratio is of the order of 1/1.
• heparin compositions are obtained comprising fractions of which at least 25% have a molecular weight of less than 2.5 kDa and at least 40% have a molecular weight of more than 20 kDa.
• the heparin / protamine ratio is of the order of 1/2.
• Heparin compositions are then obtained essentially comprising fractions having a molecular mass of less than 2.5 kDa,
• heparin compositions free of protamine are obtained.
• heparin compositions of the invention have made it possible to demonstrate, in a surprising manner, that they are practically devoid of hemorrhagic activity and at the same time retain their antithrombotic property.
• compositions according to the invention were capable of inhibiting the hydrolytic activity of human leukocyte elastase, more effectively than unfractionated heparin.
• the elimination of the risk of haemorrhage, in accordance with the invention makes it possible to envisage administration by the parenteral route or by bronchopulmonary aerosol, in the treatment of certain bronchopulmonary conditions which may involve an excess of leukocytic elastase, such as acute respiratory distress syndromes, cystic fibrosis, chronic obstructive pulmonary disease.
• heparin compositions according to the invention which are stable and non-toxic, can be used for the preparation of medicaments useful in various therapeutic applications. These applications are those of heparin and its conventional derivatives, including cases where heparin is contraindicated because of the risk of bleeding that the patient presents. They can be used in particular for the preparation of medicaments for the treatment and prevention of venous or arterial thromboses or else to prevent activation of coagulation in the extracorporeal circulation.
• the invention therefore also relates to pharmaceutical compositions comprising an amount therapeutically effective heparin composition according to the invention as described above, in combination with a pharmaceutically acceptable vehicle.
• They may, for example, be antithrombotic pharmaceutical compositions or else for the inhibition of the hydrolytic activity of human leukocyte elastase.
• heparin fractions of these compositions can be in the form of a pharmaceutically acceptable salt according to conventional methods.
• compositions according to the invention are advantageously injectable formulations intended in particular for administration by the parenteral route.
• formulations suitable for administration by bronchopulmonary route are advantageously provided.
• FIG. 1 is a comparative graph of the hemorrhagic activity of unfractionated heparin, low molecular weight heparin and non hemorrhagic heparin compositions according to the invention (S1, S2, S3);
• FIG. 2 is a comparative graph of the antithrombotic activity of unfractionated heparin, low molecular weight heparin and heparin compositions according to the invention (S1, S2, S3).
• the mixture thus obtained is centrifuged for 10 minutes and the supernatant is recovered which is lyophilized.
• a solution diluted to 1/20 has two absorption peaks at the following wavelengths:
• each bottle contains 0.7 ml of supernatant solution. 12 identical assays were carried out to verify the reproducibility: the results are given in Table III below:
• the assay of the proteins in the supernatants S1 and S2, respectively prepared according to Examples 1 and 2, is carried out according to the Pierce method (Pierce laboratory reagent kit).
• T0 ligation of the vena cava
• the supernatant S1 has no effect on blood cells.
• the supernatant S2 obtained by neutralization according to a heparin / protamine ratio of 1/2, does not exert any hemorrhagic activity but has a reduced antithrombotic activity.
• FIG. 2 shows that the heparin fractions obtained according to the invention exhibit an interesting antithrombotic activity.
• SI fraction heparin / protamine ratio of 1/1
• this activity is comparable to that of heparins which are not neutralized in accordance with the invention.
• results obtained show that, as a preventive measure, SI exerts an antithrombotic activity comparable to that of heparin and LOVENOX, 24 hours after the induction of thrombosis.
• the excitation time is fixed at 2 minutes and the observation time at 10 minutes.
• Duration embolization duration between the first and the embolus embolus ernier of detaching the clot.
• Number of emboli number of emboli coming off the clot.
• the supernatant S1 (example 1) exerts a significant antithrombotic activity compared to the placebo group, which persists after 90 minutes (TO + 90 min). This activity is more important than that of heparin injected at the same dose, after 30 and 60 minutes (TO + 30 and TO + 60 min).
• the observation time is fixed at 10 minutes.
• SI exerts an antithrombotic activity comparable to that of non-neutralized heparin injected at the same dose and reduces the number of embolisms as well as the duration of embolization in a statistically significant manner, b. Study 2
• T0 + 6h induction of the third arterial thrombosis.
• the observation time is fixed at 10 minutes.
• SI exerts an antithrombotic activity comparable to that of heparin which is not neutralized by protamine.
• the studies described above show that the antithrombotic activity is observed in the three experimental thrombosis models, namely the venous model induced by stasis, the arterial thrombosis model induced by free radicals and the arterial thrombosis model induced by endothelial laser injury.
• the fraction of heparin obtained from a low molecular weight heparin has a greater antithrombotic activity than that of the same low molecular weight heparin not treated in in vitro by protamine and also greater than that of the fractions obtained from unfractionated heparins and not treated in vitro with protamine, while no longer presenting any risk of haemorrhage.
• the method according to the invention allows, in a simple and inexpensive manner, practically to suppress the hemorrhagic activity of heparins while retaining their antithrombotic activity.

Applications Claiming Priority (3)

Publications (1)

Family

ID=9466541

Family Applications (1)

Country Status (9)

Families Citing this family (16)

Family Cites Families (6)

• 1994
  • 1994-08-29 FR FR9410380A patent/FR2723847A1/fr active Pending
• 1995
  • 1995-05-29 AU AU24171/95A patent/AU696954B2/en not_active Ceased
  • 1995-05-29 JP JP8508580A patent/JPH09510736A/ja not_active Withdrawn
  • 1995-05-29 US US08/793,314 patent/US5922358A/en not_active Expired - Fee Related
  • 1995-05-29 EP EP95918118A patent/EP0779814A1/fr not_active Withdrawn
  • 1995-05-29 CN CN95195343A patent/CN1159162A/zh active Pending
  • 1995-05-29 WO PCT/IB1995/000405 patent/WO1996006623A1/fr not_active Application Discontinuation
  • 1995-05-29 RU RU97104917/14A patent/RU2151602C1/ru active
  • 1995-05-29 CA CA002198722A patent/CA2198722A1/en not_active Abandoned

Non-Patent Citations (1)

Also Published As

Similar Documents

Legal Events