HEMOSTATIC COMPOSITIONS AND METHODS OF MAKING THEREOF
20220096708 · 2022-03-31
Inventors
- Shuang Chen (Guangzhou, CN)
- Yufu Li (Somerville, NJ, US)
- Dengmin Feng (Guangzhou, CN)
- Xiang Wan (Guangzhou, CN)
Cpc classification
A61K47/18
HUMAN NECESSITIES
C08L1/04
CHEMISTRY; METALLURGY
A61L2300/418
HUMAN NECESSITIES
A61L24/108
HUMAN NECESSITIES
A61L2300/232
HUMAN NECESSITIES
A61K9/16
HUMAN NECESSITIES
C08L1/04
CHEMISTRY; METALLURGY
A61L2300/802
HUMAN NECESSITIES
C08J2389/00
CHEMISTRY; METALLURGY
A61L2430/36
HUMAN NECESSITIES
International classification
A61K47/18
HUMAN NECESSITIES
A61K9/16
HUMAN NECESSITIES
A61L24/00
HUMAN NECESSITIES
Abstract
The present invention is directed to hemostatic compositions comprising at least partially integrated agglomerated ORC fibers, fibrinogen, and thrombin and methods of forming a powdered hemostatic composition, comprising the steps of: forming a suspension of a mixture comprising particles of fibrinogen, thrombin, ORC fibers in a non-aqueous low boiling solvent; spraying the suspension through a nozzle onto a substrate, allowing the non-aqueous solvent to evaporate; separating from the substrate and sieving the composition.
Claims
1. A method of forming a powdered hemostatic composition, comprising the steps of: a) forming a suspension of a mixture comprising particles of fibrinogen, thrombin, ORC fibers in a non-aqueous low boiling solvent; b) spraying the suspension through a nozzle onto a substrate, c) allowing the non-aqueous solvent to evaporate; d) separating the composition from the substrate and sieving the composition; and thus forming the powdered hemostatic composition.
2. The method of claim 1, wherein said non-aqueous low boiling solvent comprises Hydrofluoroether C4F9OCH3.
3. The method of claim 1, wherein said non-aqueous low boiling solvent comprises HFE7100.
4. The method of claim 1, wherein said suspension further comprises Tris.
5. The method of claim 1, wherein said suspension further comprises calcium chloride.
6. The method of claim 1, wherein said suspension comprises a fibrin sealant powder which comprises about 90% of fibrinogen, about 8% of thrombin, and about 2.5% calcium chloride by weight.
7. The method of claim 6, wherein said powdered hemostatic composition has a ratio of fibrin sealant powder to ORC from about 1:1 to about 10:1 by weight.
8. The method of claim 1, wherein said powdered hemostatic composition comprises powder having particle size predominantly in the range from about 250 to about 850 microns.
9. The method of claim 8, wherein said powdered hemostatic composition comprises powder having particle size predominantly in the range from about 355 to about 850 microns.
10. The method of claim 1, wherein said powdered hemostatic composition comprises at least partially integrated agglomerated ORC fibers, fibrinogen, and thrombin.
11-18. (canceled)
Description
BRIEF DESCRIPTION OF FIGURES
[0031]
[0032]
[0033]
[0034]
[0035]
[0036]
[0037]
[0038]
[0039]
DETAILED DESCRIPTION
[0040] The inventors have discovered hemostatic materials and process for making thereof, the hemostatic materials having surprising and highly beneficial properties for hemostasis.
[0041] The hemostatic material according to the present invention is made from oxidized cellulose-based fiber materials, more preferably form oxidized regenerated cellulose powder, fibrinogen powder, and thrombin powder. The hemostatic material according to the present invention represents at least partially integrated ORC fibers, fibrinogen, and thrombin in a form of a powder.
[0042] Referring to
[0048] In one embodiment, Tris, or Tris(hydroxymethyl)aminomethane buffer in a powder form is added to the fibrinogen, thrombin, and ORC mixture for pH adjustment. Then the mixed composition was added to HFE to form a suspension. In one embodiment, the cooling/chilling effect of the material stream during spraying due to HFE evaporation allows some ambient moisture to be absorbed onto or into the resulting hemostatic material. Any excessive moisture thus absorbed is removed in the final drying step in vacuum oven drying.
[0049] According to one aspect of the present invention, the ratio of fibrinogen/thrombin mixture to ORC powder in the inventive hemostatic material is from about 1:1 to about 10:1 by weight.
[0050] According to one aspect of the present invention the inventive hemostatic material comprises particles having size of 250-850 microns.
[0051] According to one aspect of the present invention the inventive hemostatic material comprises substantially uniformly distributed at least partially integrated ORC fibers, fibrinogen, and thrombin in a form of a powder
[0052] According to one aspect of the present invention, the inventive hemostatic material has high uniformity, integration, fast gelling/clotting, and strong adhesion force.
[0053] According to one aspect of the present invention, the collecting surface or substrate onto which the suspension is sprayed, comprises an inert non-woven felt or mesh or a steel plate.
Example 1. Preparation of Hemostatic Compositions
[0054] The individual components of the hemostatic compositions of the present invention were prepared as described below.
[0055] Fibrinogen. Any method of preparation of fibrinogen powder can be utilized, including lyophilization, freeze drying, etc. In the instant example, fibrinogen powder was prepared by spray drying method (Spray dryer manufacturer: ProCepT, Model: 4M8-TriX). Fibrinogen solution is a formulation commercially available from Bioseal Biotech CO. LTD, Located in Guangzhou, China, and comprising fibrinogen, albumin, and other needed reagents in WFI. The fibrinogen solution was first atomized through a spray nozzle in a hot airflow, then dried instantly. The spray drying parameters were as shown in Table 1
TABLE-US-00001 TABLE 1 Feed Rate 130 ml/h Drying Columns 3 (Mode II) Column Air Flow 0.6 m.sup.3/min Inlet Air Temperature 150° C. Nozzle Diameter 0.8 mm Atomizing Air Flow 12 L/min Cyclone Gas 0.15 m.sup.3/min
[0056] Thrombin. Any method of preparation of thrombin powder can be utilized, including lyophilization, freeze drying, etc. In the instant example, thrombin powder was prepared by spray drying method with thrombin formulation solution. Thrombin solution was the formulation commercially available from Bioseal Biotech CO. LTD, Located in Guangzhou, China, and comprising thrombin, albumin, and other needed reagents in WFI. The spray drying parameters were as shown in Table 2
TABLE-US-00002 TABLE 2 Feed Rate 258 ± 20 ml/h Drying Columns 2 Column Air Flow 0.3 m.sup.3/min Cooling Air Flow 0.3 m.sup.3/min Inlet Air Temperature 160° C. Nozzle Diameter 0.4 mm Atomizing Air Flow 7 L/min Cyclone Gas 0.1 m.sup.3/min
[0057] The thrombin and fibrinogen powders were then mixed together for preparation of the composite by the ratio of 89.7% of fibrinogen 7.8% of thrombin and 2.5% calcium chloride by weight, thus forming fibrin sealant powder.
[0058] The source of fibrinogen and thrombin was Porcine blood plasma which was fractionated to obtain fibrinogen and thrombin. and supplied by Bioseal Biotech CO. LTD, Located in Guangzhou, China
[0059] The ORC powder can be obtained by processing of the Surgicel original fabric. A reference is made to the U.S. Provisional Patent Application No. 62/251,773 by Yi-Lan Wang, filed 6 Nov. 2015 and titled “Compacted Hemostatic Cellulosic Aggregates”, which is incorporated by reference in its entirety for all purposes.
[0060] Briefly, the ORC powder was obtained by processing of the Surgicel original fabric in the following process:
1) split and cut the fabric into about 2″×8″ pieces,
2) mill the fabrics into the powder particle size (D50 less than 94 microns) using known milling methods. One of the methods used in the preparations is the ball mill method—place ˜100 grams of fabric into a 500-ml zirconia jar, then place 12 to 13 pieces of 20 mm zirconia balls (agates) into the same jar, cover and fix the jar in a Retsch planetary ball mill (Model PM100), mill the fabric with 450 rpm for 20 minutes, transfer the milled powders onto a 8″ dia and 300—micron opening sieve, separate the agates and the powders by slightly shaking, and collect the powders.
[0061] The inventive hemostatic compositions were prepared as follows by using co-spraying methods. 1 part of ORC fiber was combined with 1 part, or 2 parts, or 5 parts, or 10 parts of fibrin sealant powders, by weight. Thus, as an example, 10 g of ORC powder was combined with 10 g, 20 g, 50 g, or 100 g of fibrin sealant mixed powders, to produce 20 g, 30 g, 50 g, or 100 g of mixture.
[0062] A small amount of Tris was added to adjust pH to 7.0 for each respected ORC:Fibrin sealant ratio. pH was adjusted by placing the powder on a wetting surface and measuring the resulting pH and evaluating the amount of TRIS needed for obtaining a neutral pH of 7. The sample was then discarded. A corresponding proportional amount of dry powder of Tris was then added to the powder mixture, prior to co-spraying.
[0063] ORC is not per se neutralized as Tris is added in dry form. ORC is being neutralized when the whole powder formulation is wetted during the application and the Tris is dissolved. A low boiling non-aqueous solbent was utilized for making a suspension of FS and ORC powders. Hydrofluoroether C4F9OCH3 was used, obtained as HFE 7100, for instance supplied by 3M as Novec 7100 Engineered Fluid, having boiling point of 61° C. HFE7100 solvent was added to the powders compositions and filtered through 150 μm sieve. The evenly distributed suspension was created by constantly agitating at 90 rpm/min in the reservoir at 20±5° C. temperature. The suspended components were sprayed through a 0.7 mm diameter nozzle. The type of the nozzle used was B1/8VAU-316SS+SUV67-316SS manufactured by Spraying Systems Co. The flow through the nozzle was at a flow rate of 130 ml/min, onto a non-woven fabric or stainless steel substrate at 20±5° C. temperature.
[0064] Upon spraying the suspension, most of the HFE 7100 solvent was evaporating. The HFE 7100 solvent residues and the absorbed ambient moisture in the powder, if any, were allowed to evaporate in a vacuum drying oven for 24 h±5 h at 20±5° C.
[0065] The resulting hemostatic composition was scooped off or peeled off or otherwise separated from the substrate, and sequentially passed through sieves having 850 μm, 355 μm, 250 μm openings.
[0066] Table 3 shows parameters used for co-spraying compositions
TABLE-US-00003 TABLE 3 PARAMETERS FOR CO-SPRAYING THE COMPOSITION -fan pressure 0.3 bar atomizing pressure 3 bar flow rate 130 ml/min liquid pressure 16 kpa Nozzle Diameter 0.7 mm agitation speed 90 rpm/min
[0067] As comparative examples, pure fibrin sealant mixture composition with no ORC and no Tris was also prepared by the same spray method HFE7100
Example 2. Comparison of Mechanically Mixed Vs. Spray Mixed Hemostatic Compositions Gelling
[0068] Rapid gelling and formation of strong gels is important for hemostatic materials.
[0069] The inventive hemostatic composition was prepared as described above by co-spray method.
[0070] The comparative mechanically mixed composition was prepared by manually shaking dry powders, i.e. FS and ORC powders obtained as described above, by manually shaking in a container into an evenly mixed composition, with no co-spraying performed. The compositions included all the same components, including Tris, with the difference being methods of mixing.
[0071] Fibrin sealant powder to ORC ratios tested were: Fibrin sealant (FS):ORC ratios—1:1; 2:1; 5:1; 10:1 (by weight). Thus for 1:1 FS/ORC ratio, 1 part of fibrin sealant powder (comprising fibrinogen, thrombin, calcium chloride) is combined with 1 part of ORC powder (by weight).
[0072] Mechanically mixed composition and the inventive spray mixed composition were then added to 20 ml of water in a 50-ml vial in the amount of 200 mg on the top of the water surface. After 2 min for gelling, the vial was turned upside down and observations made if a gelled layer of composition was formed in which case the water was observed sealed by the gelled layer and was held on the bottom of the vial by the formed gel layer.
[0073] Referring now to
[0080] Analysis of the results shown in
Example 3. In Vitro Testing of Blood Clotting
[0081] In vitro clotting of blood by several inventive and also comparative compositions was tested as follows.
[0082] 20 ml of citrated whole blood (porcine) was added to a 50-ml vial. 200 mg of hemostatic compositions being tested were added on the top of the blood surface. After 2 min for clotting, the vial was turned upside down and observations of blood clotting were made. In case of complete clotting, the clotted blood stays in the upper part of the vial turned upside down. In case of incomplete clotting, blood remains fluid and drains towards the lower part of the vial due to the gravitational force.
[0083] Comparative excipients added to fibrin sealant powder instead of ORC were Trehalose, PEG4000, Mannitol, and Alfa-cellulose (α-cellulose). All excipients were purchased from Aladdin industrial corporation. Fibrin sealant powder mixtures with Trehalose, PEG 4000, Mannitol, or Alfa-cellulose were prepared by spray method as described above in 10:1 ratio, i.e. with 10 parts of fibrin sealant (FS) powder combined with 1 part of the respective excipient. The total amount of inventive and also comparative compositions added to 20 ml of blood was 200 mg.
[0084] Referring now to
[0093] Analysis of the results presented in
[0094] Using the same testing methods, additional in vitro blood clotting testing was performed for inventive hemostatic composition and comparative mechanically mixed compositions prepared by manually shaking dry powders in a container as well as for fibrin sealant powder only with no ORC
[0095] Referring now to
[0106] Analysis of the results presented in
Example 4. Composition Solubilisation
[0107] Rapid solubilisation or solubility of a powdered hemostatic composition when in contact with bodily fluids can help to establish rapid hemostasis and indicates rapid interaction with fluids. The visual test of solubilisation was performed as follows: 1 gram of tested hemostatic powdered composition was evenly applied to an area of a wetting substrate which comprising a non-woven fabric positioned on top of a sponge material which was placed in a tray with pure water. After the tested powdered hemostatic composition was applied to the surface of the wetting substrate, visual observation of the composition solubility was performed and results recorded at zero time (immediately after applying the composition, at 1 min and at 2 min after applying the tested composition.
[0108] Referring now to
[0109] Referring now to
[0110] Referring now to
[0111] The solubility of inventive hemostatic composition prepared by the spray method was affected by the concentration of the ORC component. Even at low concentrations of ORC, the solubility of the composition has improved.
Example 5. Particle Size Effects
[0112] The effects of the particle size on the performance of the inventive hemostatic compositions were evaluated. Particle size was controlled by sequentially passing the composition through sieves with apertures of 850 μm, 355 μm and 250 μm. Inventive composition powders were separated into size groups of predominantly above 850 μm, predominantly 355-850 μm, predominantly 250-355 μm and predominantly below 250 μm. Inventive hemostatic compositions made with 5:1 FS/ORC ratio were tested for solubility.
[0113] Referring now to
Example 6. Effects of Tris Addition
[0114] A peel test of the inventive compositions with added Tris and without added Tris was performed. Tris additions were titrated to achieve pH=7. Tris powder was ground and passed through a 150 μm sieve. The powder of below 150 μm was collected and added the pre-determined amount into the dry mixture to adjust the pH of the composition, prior to co-spray.
[0115] The peel test was performed as follows. 0.5 g of the Inventive composition was applied to the corium tissue, covered by a composite bi-layer matrix which was pressed into the powder for 3 minutes, the sample-from-tissue separation force was measured by an Instron tensile testing machine and recorded as force per unit width (N/m). The composite bi-layer matrix comprised a layer of synthetic absorbable poly (glycolide-co-lactide) (PGL, 90/10 mol/mol) nonwoven fabric needlepunched into a knitted carboxylic-oxidized regenerated cellulose fabric (ORC), as described in U.S. Pat. No. 7,666,803 by D. Shetty et al., titled “Reinforced absorbable multilayered fabric for use in medical devices”, which is incorporated by reference herein.
[0116] Referring now to Table NN, adhesion forces of inventive formulations are shown as a function of ORC addition. While the adhesion is lower at higher ORC content even 1:1 FS powder:ORC fiber formulation has appreciable peel force.
[0117] Referring now to Table 4, adhesion Forces of inventive formulations with and without Tris are shown for different FS/ORC ratios along with corresponding pH values. TRIS was added in weight percentages listed to adjust pH to 7.0. While all compositions have exhibited high peel forces, presence of TRIS clearly resulted in higher peel forces for the same FS/ORC ratios, with some showing 2-4 times higher peel force.
TABLE-US-00004 TABLE 4 Adhesion Forces of inventive formulations with and without Tris Composition With no Tris added With Tris added FS/ORC Peel Force Peel Force Tris ratio N/m pH N/m pH % by weight 1:1 26.7 2 72.6 7 20 2:1 53.8 2 127.5 7 14.3 5:1 41.2 5 235.9 7 7.7 10:1 221.7 5.5 >340 7 4.4 (Above the upper limit of measurement)
[0118] The analysis of data indicates surprising improvements in adhesive force or peel force for inventive composition having neutral pH achieved by Tris addition. While the force is somewhat lower
Example 7. Characterization of Particles
[0119] Referring now to
[0120] Examination of the inventive composition in powder form shows the components well mixed and the biologics were closely attached on the ORC fibers.
Example 8. Hemostasis Testing
[0121] An in vivo test of hemostatic efficacy in liver abrasion model using the inventive hemostatic compositions was performed as follows. A liver abrasion model was created by creating an oozing area of 3 cm×3 cm on the surface of the porcine liver. 0.5 g of the inventive hemostatic composition having FS/ORC ratio of 5:1 was applied to cover the oozing area without any tamponade applied. Hemostasis was achieved in under 2 min.
[0122] An in vivo test of hemostatic efficacy in liver resection model using the inventive hemostatic compositions was performed as follows. A liver resection model was created by using the Pringle manoeuvre which is a surgical manoeuvre used in some abdominal operations whereby a large atraumatic haemostat is applied as a clamp. The Pringle manoeuvre was applied to control bleeding first, then a cut 5 cm long and 5 cm wide of the liver tissue was created along the liver edge to expose bile duct. Immediately after, the inventive hemostatic composition powder was applied to cover the transection plane, spraying saline simultaneously until bleeding was stopped. The Pringle clamp was then released to examine the results. It was observed that hemostasis was achieved and bile leak was prevented after the Pringle clamp was released. The hemostasis was achieved in 2 min.