Stability of antibiotics and amino acids in two synthetic L-amino acid solutions commonly used for total parenteral nutrition in children

Antimicrob Agents Chemother. 1978 Apr;13(4):555-8. doi: 10.1128/AAC.13.4.555.


The stability and interaction at 29 degrees C of ampicillin, carbenicillin, gentamicin, and polymyxin B were examined in a common electrolyte solution, invertose darrow, and in two synthetic l-amino acid solutions, one commercial (vamin with fructose; Vitrum) and the other a neonatal preparation modified for use in newborn infants. The concentration of amino acids was measured before and after the addition of these antibiotics. The concentration of antibiotics was measured over a 24-h period with a microbiological method. The concentration of ampicillin in invertose darrow fell 52%, and in vamin with fructose it fell 69%, whereas in the neonatal preparation the fall was only 22%. The concentration of carbenicillin in vamin with fructose fell 37%, and in the neonatal preparation it fell 31%. The combination of ampicillin or carbenicillin with gentamicin or polymyxin B did not influence the activity of the penicillins. The concentration of gentamicin and polymyxin B was unchanged in all solutions over a 24-h period. With the exception of cystine, the concentration of all amino acids remained constant after 24 h in the neonatal preparation with and without the different combinations of antibiotics. For cystine there was a fall of 20 to 30%.

MeSH terms

  • Amino Acids / analysis*
  • Anti-Bacterial Agents / analysis*
  • Drug Stability
  • Humans
  • Hydrogen-Ion Concentration
  • Infant, Newborn
  • Parenteral Nutrition*
  • Parenteral Nutrition, Total*
  • Time Factors


  • Amino Acids
  • Anti-Bacterial Agents