Viscoelastic solution

Abstract: Viscoelastic solution including a buffered solu­ tion, 1-8% cellulose gum and 1-8% chondroitin sulfate, pH adjusted to 7.2-7.6 at a osmolality between 200-­ 400MOSM. The buffered solution can be HEPES buffered minimum essential media (MEM), phosphate buffer system (PBS), balanced salt solution, or TC199.

Description: The present invention pertains to a viscoelastic solution which is used to protect cells from mechanical trauma, to maintain or create tissue spaces, to ensure separation and lubrication of tissue surfaces, to permit the manipulation of tissues without mechanical damage, and to prevent and control movement and activities of certain cells. There have been numerous prior art solutions such as a non-inflammatory, high molecular weight fraction of sodium hyaluronate sold under the trade mark Healon. The present invention provides a viscoelastic solution which includes good coating properties and natural occurring bicompatible polymer. The general purpose of the present invention is a viscoelastic solution which provides a buffered pH neutral solution as a base, and includes the attributes of the combination of chondroitin sulfate and hydroxy-propyl methyl cellulose. The invention provides a viscoelastic solution comprising: (a) a buffered solution; (b) hydroxy-propyl methyl cellulose; and (c) chondroitin sulfate; whereby the viscoelastic solution is buffer pH- adjusted. In a preferred form of the invention the viscoelastic solution has an osmolality in the range 200 to 400 m.Os.mol/kg and a pH of 7.2 - 7.6. In another preferred form of the invention the viscoelastic solution comprises: (a) buffered balanced salt solution; (b) 1-8% hydroxy-propyl methyl cellulose; and (c) 1-8% chondroitin sulfate pH- adjusted to 7.2-7.6 at osmolality between 200 - 400 m.Os.mol/kg. The chondroitin sulfate can be used, for example, in an amount of 2 - 4%. An example of a viscoelastic solution containing such an amount of chondroitin sulfate is one comprising: (a) a solution from a group of: a buffered balanced salt solution, a minimum essential medium buffered with N-2-hydroxyethylpiperazine-N'-ethane sulphonic acid, phosphate-buffered system and GIBCO TC 199; (b) 1-8% of hydroxy-propyl methyl cellulose; and (c) 2-4% of chondroitin sulfate; the pH of the viscoelastic solution being in the range from 7.2 to 7.6 at osmolality between 200-400 m.Os.mol/kg. One significant aspect and feature of the present invention is a viscoelastic solution which provides better viscosity including the viscosity properties of the hydroxypropyl methyl cellulose and the lubricating property of the chondroitin sulfate. Another significant aspect and feature of the present invention is providing a buffered pH neutral solution as a base for the viscoelastic solution. A further significant aspect and feature of the present invention is a viscoelastic solution which provides cell protection and cell coating. The solution provides maintenance of the tissue space, the chondroitin sulfate lubricates the tissue while the hydroxy-propyl methyl cellulose provides tissue manipulation. There is now described, by way of example, a viscoelastic solution of the invention. The viscoelastic solution includes a buffered solution, 1-8% hydroxy-propyl methyl cellulose and 1-8% chondroitin sulfate, pH-adjusted to 7.2 - 7.6% at osmolality between 200-400 m.Os.mol/kg. The buffered solution can be selected from a minimum essential medium buffered with N-2-hydroxyethylpiperazine-N'-ethane sulphonic acid, (HEPES), phosphate buffer system (PBS), balanced salt solution, or the tissue culture medium manufactured by Gibco under the Trade Mark TC 199. Preferably, the hydroxy-propyl methyl cellulose can be at 4 percent while the chondroitin sulfate can be at 2-4 percent volume.

Claims: A viscoelastic solution comprising: (a) a buffered solution; (b) hydroxy-propyl methyl cellulose; and (c) chondroitin sulfate; whereby the viscoelastic solution is buffer pH-adjusted. A viscoelastic solution according to Claim 1, which has an osmolality in the range 200 to 400m.Os.mol/kg. and a pH of 7.2 - 7.6. A viscoelastic solution according to Claim 1, comprising: (a) buffered balanced salt solution; (b) 1-8% hydroxy-propyl methyl cellulose; and (c) 1-8% chondroitin sulfate pH-adjusted to 7.2 - 7.6 at osmolality between 200 - 400 m.Os.mol/kg. A viscoelastic solution, according to any of the preceding claims, in which the chondroitin sulfate is present in an amount of 2 - 4%. A viscoelastic solution according to Claim 1, comprising: (a) a solution from a group of: a buffered balanced salt solution, a minimum essential medium buffered with N-2-hydroxyethylpiperazine-N'-ethane sulphonic acid and phosphate-buffered system; (b) 1-8% of hydroxy-propyl methyl cellulose; and (c) 2-4% of chondroitin sulfate; the pH of the viscoelastic solution being in the range from 7.2 to 7.6 at osmolality between 200 -400 m.Os.mol/kg.

Inventors: LINDSTROM RICHARD L, SKELNIK DEBRA L, LINDSTROM, RICHARD L., SKELNIK, DEBRA L.
Applicants: LINDSTROM RICHARD L, SKELNIK DEBRA L, LINDSTROM, RICHARD L., SKELNIK, DEBRA L.
Application year: 1986
Main classification: C08L1
IPC codes: C08L1