Automatic Particle Counters Used for Regulatory Monitoring of Particulates in LVPs: Statistical Analysis

Studies were conducted comparing a method that uses an automatic particle counter with the official United States Pharmacopeia microscopic method. Test solutions of a fine test dust and 28 samples representing five different parenteral products in glass and/or plastic containers were compared by both methods at two different count levels, i.e., particles 10–24.9 μm and particles ≥25 μm in effective linear dimension. Statistical tests showed the machine counting method to be an acceptable screening tool for particulates in the products examined. The overall mean count at both levels was higher for glass containers and indicates that plastic containers may reduce the particle count. A comparison of counts from one product contained in both glass and plastic, however, indicated higher counts with the automatic particle counter for the product in plastic. Additional data are needed to obtain definitive results for the glass-plastic comparison.