RT Journal Article SR Electronic T1 Physical stability of an all-in-one parenteral nutrition admixture for preterm infants upon mixing with micronutrients and drugs JF European Journal of Hospital Pharmacy JO Eur J Hosp Pharm FD British Medical Journal Publishing Group SP 36 OP 42 DO 10.1136/ejhpharm-2018-001562 VO 27 IS 1 A1 Vigdis Staven A1 Siri Wang A1 Ingrid Grønlie A1 Ingunn Tho YR 2020 UL http://ejhp.bmj.com/content/27/1/36.abstract AB Objectives The main objective was to investigate Y-site compatibility of intravenous drugs with one standard total parenteral nutrition (TPN) admixture for preterm infants. Since micro-precipitation was observed in the water phase after addition of trace elements, the concentration effect on micro-precipitation formation developed as a sub-goal.Methods Seven drugs (ampicillin, ceftazidime, fluconazole, fosphenytoin, furosemide, metronidazole and paracetamol) were mixed in three mixing ratios with one preterm TPN admixture. Samples were investigated within 1 hour and again after 4 hours. Precipitation was studied in a lipid-free version called TPNaq by light obscuration, turbidimetry and visual examination. Emulsion stability data were assessed by light obscuration and laser diffraction. pH was measured to assess the theoretical risk of precipitation and emulsion destabilisation. The influence of different concentrations of trace elements on precipitation was investigated by visual examination, turbidimetry and light obscuration.Results Ampicillin, ceftazidime, fosphenytoin and furosemide led to precipitation after mixing with TPNaq. In some samples of TPN and fluconazole, metronidazole and paracetamol, the emulsion droplet size was above the acceptance limit, although this might also be inherent to the TPN admixture. An unexpected formation of micro-precipitate correlating with increasing amounts of added trace elements might be caused by an interaction of cysteine and copper, and complicated the compatibility assessment with drugs.Conclusions The micro-precipitate resulting from the addition of trace elements should be investigated further. This study did not provide sufficient evidence to recommend Y-site infusion of the tested drugs and the preterm admixture; however, it might offer some additional support to other compatibility data.