Roksvaag P O, Rydstrøm P, Smistad G, Waaler T
Military Pharmaceutical Laboratory, Norwegian Joint Medical Service, Oslo.
Acta Pharm Nord. 1990;2(5):319-26.
In the seventies, it was shown that particles were generated in soft polyvinyl chloride (PVC) infusion fluid bags when they were shaken. In this investigation an exponentially modified log-normal distribution (EMLN) is fitted to the particle data. Using the formula for the volume of a sphere, the number-density distribution is converted into a volume-density distribution. The total particle load in the samples is estimated by integration for total particle volume. The results are expressed as volume concentration in plain SI-units (microliters/l). A four-factor analysis of variance demonstrates that the mechanism of the contamination process is most probably an emulsification of low molecular weight additives in the PVC plastic, i.e. di(2-ethylhexyl) phthalate (DEHP), epoxidized vegetable oils (EVO), and others.
