Hemostatic surgical dressings

Claim 1

A SURGICAL DRESSING HAVING ADJACENT A WOUND-CONTACTING EXTERNAL SURFACE THEREOF, A NON-TOXIC HYDROPHILIC ALIPHATIC POLY-OL COMPOUND NORMALLY EXISTING IN NONCRYSTALLINE CONDITION AND IN AMOUNT SUFFICIENT TO PRODUCE EASY REMOVAL OF SAID DRESSING FROM A CLOT OF BLOOD, SAID DRESSING ALSO CONTAINING CELLULOSE DERIVATIVE OF THE GROUP CONSISTING OF FREE ACID CELLULOSE GLYCOLIC ACID ETHER AND FREE ACID CELLULOSE HYDROXYPROPIONIC ACID ETHER IN HEMOSTATIC AMOUNT AT LEAST ABOUT 0.30 MG. PER SQUARE INCH OF SAID SURFACE, SAID CELLULOSE DERIVATIVE HAVING DEGREE OF SUBSTITUTION AT LEAST ABOUT 0.5 AND DEGREE OF NEUTRALIZATION IN THE APROXIMATE RANGE OF 0 TO 60% AND SUFFICIENTLY LOW SO THAT THE FREE CARBOXY CONTENT OF THE CELLULOSE IS AT LEAST 0.5 PER GLUCOSE UNIT, SAID CELLULOSE DERIVATIVE FURTHER HAVING DEGREE OF POLYMERIZATION INDICATED BY VISCOSITY OF A 0.50% BY WEIGHT SOLUTION OF THE FREE ACID IN A 0.50 N NAOH SOLUTION AT 25.50* C. OF AT LEAST 5.7 SECONDS AS DETERMINED IN A MODIFIED OSTWALDFENSKE VISCOSIMETER PIPETTE ASTM D-445 #330, AS COMPARED WITH A ZERO PIPETTE READING OF 5.0 SECONDS FOR A 0.50 N. NAOH SOLUTION AT THE SAME TEMPERATURE.