ENHANCEMENT OF MICROBIOLOGICAL SAFETY LEVELS OF ASEPTICALLY ADMIXED TOTAL PARENTERAL-NUTRITION SOLUTIONS THROUGH LOW-DOSE GAMMA-IRRADIATION

This study was undertaken to determine the effect of low-dose gamma ir radiation on aseptically admixed total parenteral nutrition (TPN) solu tions to which large inocula of three test bacterial species were adde d. Microbiological safety levels were quantified in terms of sterility assurance levels (SALs), indicating the probability of contamination occurring expressed as 10-n. The radiation sensitivity (D10 values) of test bacteria in TPN solutions inoculated with a series of bacteria r ecognized as common contaminants of these products, was determined. At tainable SALs of TPN solutions containing test bacteria were subsequen tly calculated from the D10 values. Results showed that a minimum abso rbed radiation dose as low as 1.5 kGy improved the SAL of aseptically prepared TPN solutions from a probability value of 10(-3) to a value o f less than 10(-8) for the microorganisms investigated. At an absorbed dose as high as 8.3 kGy, no measurable changes in amino acid, electro lyte, glucose and lipid components of the solutions were detected. The se findings have important implications for the enhancement of microbi ological safety levels of aseptically prepared intravenous fluids in g eneral.