Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0847097 (acidity)
 15,165 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Carboxymethyl high amylose starch (CM-HAS) is proposed as a novel excipient for oral tablet formulation of bioactive agents ensuring their protection in the stomach and delivery in the intestine. Three variants of CM-HAS, with different degrees of substitution, were synthesized by starch treatment with various amounts of monochloroacetic acid. The products were dried in powder form and tablets were obtained by direct compression of mixed powders of polymeric excipient and lyophilized Escherichia coli (E. coli) bacteria. Dosage forms of CM-HAS are unswollen and compact in acidic medium, ensuring protection of active agents against acidity. Release of bacteria from CM-HAS tablets is based on the fast swelling of the tablets during the passage from gastric acidity to alkaline intestinal medium, enzymatic hydrolysis triggering their rapid, almost total dissolution. The bacteria thus formulated displayed higher survival rates in acidic gastric conditions and for longer periods than the free bacteria or than the bacteria formulated with the non-derivatized starch. The CM-HAS selected matrix also assured a good viability of bacteria after 6 months under refrigeration.
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PMID:Carboxymethyl high amylose starch (CM-HAS) as excipient for Escherichia coli oral formulations. 1584 56

The carboxymethyl high amylose starch (CM-HAS) was proposed as excipient able to protect F4 fimbriae oral vaccine against gastric acidity and pepsin, allowing its subsequent liberation in the intestinal fluid. Thus, F4 fimbriae formulated with CM-HAS as tablets displayed a markedly higher stability after 2h of incubation in simulated gastric fluid (containing pepsin) than the free, non-protected F4 fimbriae, which, in these conditions, were almost completely digested after 120 min. In the presence of pancreatin (with alpha-amylase, lipase and proteolytic activities) in simulated intestinal conditions, the F4 fimbriae were liberated from CM-HAS tablets over a period of up to 5 h. The presence of pancreatin in intestinal medium did not affect the structural stability of the F4 fimbriae major subunits. Thus, F4 fimbriae formulated with CM-HAS would retain their receptor binding activity essential for the induction of an intestinal mucosal immune response.
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PMID:Carboxymethyl high amylose starch for F4 fimbriae gastro-resistant oral formulation. 1753 98