RT Journal Article SR Electronic T1 Particulate Matter Determination in LVPs Produced in Dutch Hospital Pharmacies, Part 1: Particle-Counting Accuracy JF PDA Journal of Pharmaceutical Science and Technology JO PDA J Pharm Sci Technol FD Parenteral Drug Association (PDA) SP 81 OP 88 VO 51 IS 2 A1 Der Veen, J. Van A1 Verbrugge, Ph. A1 Van De Vaart, F. J. A1 Boom, F. A. YR 1997 UL http://journal.pda.org/content/51/2/81.abstract AB 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.