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 anesthetic is selected from the group consisting of lidocaine, bupivicaine, mepivicaine, proparacaine, and narcaine, and salts 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 16 , wherein the anesthesia lasts up to 30 minutes or more. 
     
     
         18 . An aqueous gel formulation comprising water, an anesthetic or a salt thereof, 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 salt 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.   
     
     
         21 . The method of  claim 14 , wherein the anesthetic is present in an amount of 15 mg per ml and the aqueous gel formulation is administered to the eye of a human. 
     
     
         22 . The method of  claim 21 , wherein the aqueous gel formulation is administered prior to or during a procedure selected from the group consisting of intravitreal injection, subtenon injection, conjunctival biopsy, conjunctival or corneal foreign body removal, gonioscopy, suture placement, removal of corneal sutures, removal of conjunctival sutures, removal of lid sutures, anterior chamber paracentesis, contact lens examination of retina, a procedure involving ALT/SLT laser, a procedure involving retinal lasers, placement of electroretinographic lenses, lens placement for YAG laser, incision and drainage of chalazia, lid injections, and scleral depression examination, and any combination thereof. 
     
     
         23 . The method of  claim 14 , wherein the anesthetic is present in an amount of 35 mg per ml and the aqueous gel formulation is administered to the eye of a human. 
     
     
         24 . The method of  claim 23 , wherein the aqueous gel formulation is administered prior to or during a procedure selected from the group consisting of cataract surgery, refractive surgery, supplemental topical anesthetic after peribulbar or retrobulbar block, vitreous biopsy, conjunctival biopsy, minor lid procedure, retinal cryoretinopexy, pneumatic retinopexy, pterygium surgery, strabismus surgery adjustment, conductive keratoplasty, pars plana vitrectomy, and trabeculectomy, and any combination thereof. 
     
     
         25 . An aqueous gel formulation consisting essentially of water, lidocaine hydrochloride, hydroxypropylmethylcellulose, and sodium chloride, wherein the lidocaine hydrochloride is present in an amount so as to provide a 1.5%, 2.5%, or 3.5% by weight of lidocaine in the formulation, wherein the aqueous gel formulation 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. 
     
     
         26 . A method of inducing topical anesthesia on the eyes of a human comprising:
 a) providing an aqueous gel formulation according to  claim 25 ; and   b) topically administering an effective amount of the aqueous gel formulation to the eye;   whereby anesthesia is induced on the eye.