Polymeric buffering composition

• US 5,376,306 A
• Filed: 11/05/1993
• Issued: 12/27/1994
• Est. Priority Date: 12/23/1991
• Status: Expired due to Fees

• Current Assignee: Abbott Laboratories Incorporated
• Original Assignee: Abbott Laboratories Incorporated
• Inventors: Iyer, Lokanathan M., Lyon, Kenneth S., Brotherton, Vince
• Primary Examiner(s): Schofer, Joseph L.
• Assistant Examiner(s): Cheng, Wu C.
• Application Number:
  US08/149,659
• Time in Patent Office: 417 Days
• Field of Search: 526/312, 526/328.5, 526/408.1
• US Class Current: 252/408.1
• CPC Class Codes: C07C 219/08 having at least one of the hydroxy groups esterified by a carboxylic acid having the esterifying carboxyl group bound to an acyclic carbon atom of an acyclic unsaturated carbon skeleton
• CPC Class Codes: C07C 233/38 having the carbon atom of the carboxamide group bound to a carbon atom of an acyclic unsaturated carbon skeleton
• CPC Class Codes: C08F 20/34 Esters containing nitrogen , e.g. N,N-dimethylaminoethyl (meth)acrylate
• CPC Class Codes: C08F 20/60 containing nitrogen in addition to the carbonamido nitrogen

Abstract

High molecular weight buffering compositions and polymeric buffering compositions incorporating such compositions are described. The compositions are useful in applications where lower molecular weight buffers are unsatisfactory because of their tendency to leak out of an encapsulating membrane. Methods of making such compositions are described, as well as a particular application in a fiber optic carbon dioxide physiological probe.

Claims

1. A polymeric buffering composition comprising a copolymer of a buffering composition represented by the formula:

##STR8## wherein R is hydrogen or methyl radical, and X is;

##STR9## wherein R₁ is an alkyl or hydroxyalkyl group,

R₂, R₃, and R₄ are hydrogen, alkyl, or hydroxyalkyl, and

Z^- is bicarbonate; and

a non-ionic, hydrophobic acrylate represented by the formula;

##STR10## wherein R₅ is hydrogen or methyl radical and R₆ is methyl, ethyl, or butyl radical.

2. The buffering composition of claim 1, wherein R is methyl radical, R₁ is propyl radical, and R₂, R₃, and R₄ are methyl radicals.

3. The buffering composition of claim 1, wherein R₅ and R₆ are methyl radicals.

4. An indicator matrix for use in a fiber-optic sensor suitable for monitoring physiological analyte concentration comprising:

a copolymer of a buffering composition represented by the formula;

##STR11## wherein R is hydrogen or methyl radical, and X is;

##STR12## wherein R₁ is an alkyl or hydroxyalkyl group,

R₂, R₃, and R₄ are hydrogen, alkyl, or hydroxyalkyl, and

Z^- is bicarbonate; and

a non-ionic, hydrophobic acrylate represented by the formula;

##STR13## wherein R₅ is hydrogen or methyl radical and R₆ is methyl, ethyl, or butyl radical; and

an indicator molecule capable of responding to the analyte in an optically detectable manner.

5. The indicator matrix of claim 4, wherein R is methyl radical, R₁ is propyl radical, and R₂, R₃, and R₄ are methyl radicals.

6. The indicator matrix of claim 4, wherein R₅ and R₆ are methyl radicals.

7. The indicator matrix of claim 4, wherein the indicator molecule is phenol red.

8. The indicator matrix of claim 4, wherein the analyte is carbon dioxide.