Viscoelastic gels as novel fillers

1. A biomaterial for use as a filler and/or as a body shaping product prepared by a process comprising:

(a1) mixing an autocrosslinked hyaluronic acid (ACP) powder with (HBC) a hyaluronic acid crosslinked with 1,4-butanediol diglycidyl ether (HBC)

in a weight ratio of between 10:90 and 90:10, wherein the hyaluronic acid in said ACP and HBC has a mean molecular weight of between 200,000 and 1×10 6 Da;

(b1) hydrating with saline solution or phosphate buffer, leading to a total hyaluronic acid concentration of between 12 and 27 mg/ml;

(c1) extruding at a temperature of between 25 and 65° C. through a sieve with a mesh of between 50 and 500 □m; and

(d1) sterilizing by heat from saturated steam at a temperature of between 120 and 124° C. for at least 10 min; or

(a2) mixing an autocrosslinked hyaluronic acid (ACP) gel or powder with a hyaluronic acid crosslinked with 1,4-butanediol diglycidyl ether (HBC) in gel form in a weight ratio of between 10:90 and 90:10;

(b2) crushing and homogenizing by passing through a filter with a particulate matter retention coefficient of between 25 and 150 μm; and

(c2) sterilizing by heat from saturated steam at a temperature of between 120 and 124° C. for at least 10 min.

2. A biomaterial for use as a filler and/or as a body shaping product prepared by a process comprising:

(a1) mixing a hyaluronic acid hexadecylamide (HYADD) powder with a hyaluronic acid crosslinked with 1,4-butanediol diglycidyl ether (HBC)

in a weight ratio of between 10:90 and 90:10;

(b1) hydrating with saline solution or phosphate buffer, leading to a total hyaluronic acid concentration of between 12 and 27 mg/ml;

(c1) extruding at a temperature of between 25 and 65° C. through a sieve with a mesh of between 50 and 500 μm; and

(d1) sterilizing by heat from saturated steam at a temperature of between 120 and 124° C. for at least 10 min; or

(a2) mixing a hexadecylamide (HYADD) gel or powder with a hyaluronic acid crosslinked with 1,4-butanediol diglycidyl ether (HBC) in gel form in a weight ratio of between 10:90 and 90:10;

(b2) crushing and homogenizing by passing through a filter with a particulate matter retention coefficient of between 25 and 150 μm; and

(c2) sterilizing by heat from saturated steam at a temperature of between 120 and 124° C. for at least 10 min.

3. The biomaterial as claimed in claim 1 or 2 , wherein the weight ratio is 90:10 to 50:50.

4. The biomaterial as claimed in claim 1 or 2 , wherein the weight ratio is 10:90 to 50:50 with a volume-enhancing effect.

5. The biomaterial as claimed in claim 4 , wherein the weight ratio is 25:75.

6. A process of mixing an autocrosslinked hyaluronic acid (ACP) or a hyaluronic acid hexadecylamide (HYADD) with a hyaluronic acid crosslinked with 1,4-butanediol diglycidyl ether (HBC), comprising the following steps:

(a) mixing ACP or HYADD with HBC in a ratio of ACP:HBC or HYADD:HBC of between 90:10 and 10:90;

(b) hydrating with saline solution or phosphate buffer, leading to a total hyaluronic acid concentration of between 12 and 27 mg/ml;

(c) extruding at a temperature of between 25 and 65° C. through a sieve with a mesh of between 50 and 500 μm;

(d) syringe filling; and

(e) sterilizing by heat from saturated steam at a temperature of between 120 and 124° C. for at least 10 min.

7. A process of mixing an autocrosslinked hyaluronic acid (ACP) or a hyaluronic acid hexadecylamide (HYADD) with a hyaluronic acid crosslinked with 1,4-butanediol diglycidyl ether (HBC), comprising the following steps:

(a) mixing ACP or HYADD with HBC in a ratio of ACP:HBC or HYADD:HBC of between 90:10 and 10:90;

(b) crushing and homogenizing by passing through a filter with a particulate matter retention coefficient of between 25 and 150 μm;

(c) syringe filling; and

(d) heat sterilisation with saturated steam at a temperature of between 120 and 124° C. for at least 10 min.

8. The process as claimed in claim 6 or 7 , wherein a hyaluronic acid used for the preparation of the HBC, ACP and HYADD has a mean molecular weight of between 400 and 3×10 6 Da.

9. The biomaterial as claimed in claim 1 , 4 or 5 , wherein the ACP:HBC weight ratio is 25:75.

10. The biomaterial as claimed in claim 1 or 2 , comprising saline solution as a vehicle.

11. The biomaterial as claimed in claim 1 or 2 , containing lidocaine.

12. The biomaterial as claimed in claim 9 , containing lidocaine and saline solution as a vehicle.

13. The biomaterial according to claim 1 , wherein said ACP has a mean degree of cross-linking of between 4 and 5%.

14. The biomaterial according to claim 13 , wherein the hyaluronic acid in said ACP has a mean molecular weight of about 200,000 Da.

15. The biomaterial according to claim 2 , wherein said HYADD has a mean degree of amidation/substitution of between 1 and 3% in moles.

16. The biomaterial according to claim 15 , wherein the hyaluronic acid in said HYADD has a molecular weight of between 500,000 to 730,000 Da.