Particulate matter determination in LVPs produced in Dutch hospital pharmacies, Part 1: Particle-counting accuracy

Reproducible particle counting using the light-obscuration technique is often troublesome because no absolute standard is available. Therefore, at the Laboratory of Dutch Pharmacists the "calibration-in-time" method was developed. This method enables checking of the amount of particles counted from a diluted latex suspension as a function of time. A particularity of the method is the one-step dilution procedure. The calibration-in-time method is compared with the particle-counting accuracy test according to the USP < 788 >. Advantages and disadvantages of both methods are discussed.