Particle counting by light obscuration is a technique that is used for measuring particle size distributions and for counting the number of particles in a suspension. We use it for counting the number of sub-visible particles in vials.
Using the Particle counting method, it is possible to:
- Calculate the number of sub-visible particles in products such as injection, solutions, or samples of water.
- Particulate contamination of injections and infusions consists of extraneous, mobile particles unintentionally present in the solutions. The method has vital importance for the quality control of such products.
For Material Experts:Â Instrument and measuring principle
The time a particles blocks the light when it passes a laser and is used to count and size the particles. The particles are pumped through the laser path in a capillary tube so the suspension should be aqueous and must not contain large particles.
| Instruments | Particle Measuring Systems APSS2000 |
| USP/Ph. Eur. | Ph.Eur. 2.9.19 or USP <788>. |
| Sample requirement | Counts the number of particles in a suspension |
| Measuring range | 2-125 µm |
| Sample amount | Minimum 10 vials for small volume units, for biologics 3 mL according to Ph.Eur. 2.9.19 or USP <788> |
Literature
Jack T, Brent BE, Boehne M, Müller M, Sewald K, Braun A, Wessel A, Sasse M (2010) Analysis of particulate contaminations of infusion solutions in a pediatric intensive care unit. Intensive care medicine. 36(4):707-11.
Perez M, Maiguy-Foinard A, Barthélémy C, Décaudin B, Odou P (2016) Particulate matter in injectable drugs: evaluation of risks to patients. Pharmaceutical Technology in Hospital Pharmacy.1(2):91-103.
