Aqueous gel formulation and method for inducing topical anesthesia

Abstract

Disclosed is a stable aqueous gel formulation suitable for topical use comprising water, an anesthetic (e.g., lidocaine hydrochloride), a viscoelastic polymer, and a tonicity modifier, wherein the aqueous gel formulation is free of preservatives and phosphate buffer, is isotonic with physiological fluids, and is sterile and has low particulate count. Also disclosed is a method of inducing topical anesthesia on a tissue or organ, e.g., the eye, of an animal comprising providing a stable aqueous gel formulation comprising water, an anesthetic, a viscoelastic polymer, and a tonicity modifier, wherein the aqueous gel formulation is free of preservatives and phosphate buffer, is isotonic with physiological fluids, and is sterile, and topically administering an effective amount of the aqueous gel formulation to the tissue or organ of the animal.

1 . An aqueous gel formulation comprising water, an anesthetic, a viscoelastic polymer, and a tonicity modifier, wherein the anesthetic is present in an amount of 15 mg per ml to about 50 mg per ml of the formulation, wherein the aqueous gel formulation is free of preservatives and phosphate buffer, is isotonic with physiological fluids, and is sterile having less than about 100 particles of 50 microns particle size or more per ml of the aqueous gel formulation. 
     
     
         2 . The aqueous gel formulation of  claim 1 , wherein the anesthetic is selected from the group consisting of lidocaine, bupivicaine, mepivicaine, proparacaine, and narcaine and a salt thereof. 
     
     
         3 . The aqueous gel formulation of  claim 2 , wherein the anesthetic is lidocaine hydrochloride. 
     
     
         4 . The aqueous gel formulation of  claim 1 , wherein the anesthetic is present in an amount of from 15 mg to 38 mg per ml and the aqueous gel formulation is suitable for administration to the eye. 
     
     
         5 . The aqueous gel formulation of  claim 1 , wherein the viscoelastic polymer comprises a gelling agent. 
     
     
         6 . The aqueous gel formulation of  claim 5 , wherein the gelling agent is hydroxypropylmethylcellulose. 
     
     
         7 . The aqueous gel formulation of  claim 1 , which has a pH from about 5.0 to about 7.5. 
     
     
         8 . The aqueous gel formulation of  claim 1 , which has a viscosity from about 2000 to about 10,000 cps at 25° C. 
     
     
         9 . The aqueous gel formulation of  claim 3 , wherein the viscoelastic polymer comprises hydroxypropylmethylcellulose. 
     
     
         10 . The aqueous gel formulation of  claim 9 , wherein the tonicity modifier is sodium chloride. 
     
     
         11 . A method of inducing topical anesthesia in a tissue or organ of an animal comprising:
 a) providing an aqueous gel formulation comprising water, an anesthetic, a viscoelastic polymer, and a tonicity modifier, wherein the anesthetic is present in an amount of 15 mg per ml to about 50 mg per ml of the formulation, and the gel formulation is free of preservatives and phosphate buffer, is isotonic with physiological fluids, and is sterile having less than about 100 particles of 50 microns particle size or more per ml of the aqueous gel formulation; and   b) topically administering an effective amount of the aqueous gel formulation to the tissue or organ of the animal;   whereby anesthesia is induced on the tissue or organ of the animal.   
     
     
         12 . The method of  claim 11 , wherein the wherein the anesthetic is selected from the group consisting of lidocaine, bupivicaine, mepivicaine, proparacaine, and narcaine and a salt thereof. 
     
     
         13 . The method of  claim 12 , wherein the anesthetic is lidocaine hydrochloride. 
     
     
         14 . The method of  claim 11 , wherein the anesthetic is present in an amount of from 15 mg to about 35 mg per ml and the formulation is administered to the eye of the animal. 
     
     
         15 . The method of  claim 11 , wherein the viscoelastic polymer comprises hydroxypropylmethylcellulose. 
     
     
         16 . The method of  claim 11 , wherein the anesthesia onsets within 5 minutes of administration of the aqueous gel formulation. 
     
     
         17 . The method of  claim 17 , wherein the anesthesia lasts up to 30 minutes or more. 
     
     
         18 . An aqueous gel formulation comprising water, an anesthetic, a viscoelastic polymer, and a tonicity modifier, wherein the anesthetic is present in an amount of 25 mg per ml to 38 mg per ml of the formulation, and the aqueous gel formulation is free of preservatives and phosphate buffer, is isotonic with physiological fluids, and is sterile having less than about 100 particles of 50 microns particle size or more per ml of the aqueous gel formulation and suitable for topical administration to the eye. 
     
     
         19 . The aqueous gel formulation of  claim 18 , wherein the anesthetic is lidocaine hydrochloride. 
     
     
         20 . A method of inducing topical anesthesia on the eye of an animal comprising:
 a) providing an aqueous gel formulation according to  claim 18 ; and   b) topically administering an effective amount of the aqueous gel formulation to the eye of the animal;   whereby anesthesia is induced on the eye of the animal.