A Simple Index for Measuring Particulate Contamination in Parenteral Solutions

Abstract

AbstractConcern over the recent introduction of limits for allowable particulate contamination in small volume parenterals by the United States Pharmacopeia XXI has drawn attention to the physics of systems containing small numbers of particles of varying (random) size and random identity dispersed in an aqueous mediun. In general, a size distribution of parenteral particulate characteristically consists of large numbers of small particles and relatively few particles at larger sizes. In parenteral solutions, the size distributions found tend to fit a linear power law curve of the typeIn N = C - M In Dwhere N = cumulative number of particles/unit volume at size threshold D, M is the slope of the distribution and C is a constant. A numerical index of contamination can be obtained by integrating this curve between limits, effectively an area under the curve, AUC.The limits are defined as the number of particles/unit volume (mL) at a size of 1.Oμ, and the size at which the count falls to 1 per mL. By simple ...