       Document 0938
 DOCN  M9650938
 TI    Effects of polyacrylic polymers on the lumenal proteolysis of peptide
       drugs in the colon.
 DT    9505
 AU    Bai JP; Chang LL; Guo JH; College of Pharmacy, University of Minnesota,
       Minneapolis 55455,; USA.
 SO    J Pharm Sci. 1995 Nov;84(11):1291-4. Unique Identifier : AIDSLINE
       MED/96139277
 AB    The in-vitro effectiveness of polyacrylic acid polymers in inhibiting
       degradation of insulin, calcitonin, and insulin-like growth factor-I by
       colonic lumenal contents was determined. Further, the effect of Carbopol
       974P, a polyacrylic acid polymer, on colonic absorption of insulin in
       rats was studied. The results revealed that Carbopol 934P, 971P, and
       974P all strongly inhibited microbial proteolytic activities against
       insulin, calcitonin, and insulin-like growth factor-I. Inhibition by
       Carbopol polymers was complete or almost complete when the concentration
       of each polymer in saline or in 50 or 100 mM Tris buffer was 0.4%, where
       the pH of the medium was lower than 5. The extensive inhibition by these
       polyacrylic acid polymers seems to correlate with their ability to
       acidify the incubation medium. Further, in-situ absorption studies
       showed that Carbopol 974P increased the pharmacological availability of
       colonic insulin. In summary, Carbopol polymers are useful in minimizing
       colonic proteolysis of peptide drugs.
 DE    Animal  Calcitonin/PHARMACOKINETICS  Colon/DRUG EFFECTS/*METABOLISM
       Hydrogen-Ion Concentration  Hypoglycemic Agents/PHARMACOKINETICS
       Insulin/PHARMACOKINETICS  Insulin-Like Growth Factor I/PHARMACOKINETICS
       Intestinal Absorption/DRUG EFFECTS  Male  Methylcellulose/*ANALOGS &
       DERIVATIVES/PHARMACOLOGY  Peptides/*PHARMACOKINETICS  Pharmaceutic
       Aids/*PHARMACOLOGY  Polyvinyls/*PHARMACOLOGY  Protease
       Inhibitors/*PHARMACOLOGY  Rats  Rats, Sprague-Dawley  JOURNAL ARTICLE

       SOURCE: National Library of Medicine.  NOTICE: This material may be
       protected by Copyright Law (Title 17, U.S.Code).

