Process for the preparation of autocrosslinked compounds of hyaluronic acid and the derivatives thereof by the supercritical antisolvent technique
AssigneeFidia Advanced Biopolymer s.r.l.
InventorsPaolo Pallado, Marco Baggio, Maurizio Dalle Carbonare, Lanfranco Callegaro
Life of this patent
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Abstract
Crosslinked compounds of hyaluronic acid and the derivatives thereof, prepared by the technique of precipitation induced by supercritical antisolvent (SAS), can be used to advantage for the preparation of biomaterials for use in the field of medicine and surgery and in tissue engineering for medical and surgical purposes.
Claims14
Process for the preparation of autocrosslinked compounds of hyaluronic acid and derivatives thereof by the technique of precipitation induced by antisolvent, comprising the following steps:
- a) preparing solutions of the quaternary ammonium salt of hyaluronic acid or derivatives thereof and a crosslinking agent;
- b) loading the solutions of quaternary ammonium salt and crosslinking agent container being fitted with a pump to suck up the liquid;
- c) adjusting the rotation speed to within a range of 200-1000 rpm;
- d) adjusting the temperature to within a range of −20 to 20° C.;
- e) adjusting the pressure of the fluid to below that required for precipitation of the quaternary ammonium salt of hyaluronic acid or derivatives thereof;
- f) injecting the solution of crosslinking agent into the precipitator at a pressure that is greater than that in the precipitator;
- g) optionally, injecting a buffer solution into the precipitator;
- h) increasing the temperature to a value within a range of 20 to 50° C.;
- i) leaving it to react for between 2 and 12 hours;
- j) washing the product with a flow of antisolvent at a pressure of between 60 and 150 bar;
- k) depressurizing and harvesting the product.
Process for the preparation of autocrosslinked compounds of hyaluronic acid and derivatives thereof by the technique of precipitation induced by antisolvent, comprising the following steps:
- a) preparing solutions of the quaternary ammonium salt of hyaluronic acid or derivatives thereof and a crosslinking agent;
- b) loading the solutions of quaternary ammonium salt and crosslinking agent container being fitted with a pump to suck up the liquid;
- c) adjusting the rotation speed to within a range of between 250 and 450 rpm;
- d) adjusting the temperature to within a range of −20 to 20° C.;
- e) adjusting the pressure of the fluid to below that required for precipitation of the quaternary ammonium salt of hyaluronic acid or derivatives thereof;
- f) injecting the solution of crosslinking agent into the precipitator at a pressure that is greater than that in the precipitator;
- g) optionally, injecting a buffer solution into the precipitator;
- h) increasing the temperature to a value within a range of between 15 and 40° C.;
- i) leaving it to react for between 2 and 12 hours;
- j) washing the product with a flow of antisolvent at a pressure of between 60 and 150 bar;
- k) depressurizing and harvesting the product.
Dependencies are inferred from the claim text.