Automated System for Kinetic Analysis of Particle Size Distributions for Pharmaceutically Relevant Systems

Figure 5

The pH dependence ranging from 4.5 to 8.0 of calcium phosphate particle formation ≥2 microns for a nutritional admixture stored at 37°C is monitored with simultaneous calcium addition over a 30-hour period. The concentration of calcium started at 0 mmol/L initially and reached ~12 mmol/L after 24 hours of continuous addition while the concentration of phosphates was ~24 mmol/L throughout the experiment. For pH ≥ 6, as the pH increases, the calcium addition time is shorter before the appearance of increased particle counts/mL. There are also observed inflection points in the rates of increase in particle concentrations for the admixtures where calcium phosphate precipitation was observed.