For the determination of particulate matter, two procedures, Method 1 (Light Obscuration Particle Count Test) and Method 2 (Microscopic Particle Count Test), are specified hereinafter.

Widely used across a variety of pharmaceutical applications, light obscuration is recognized by the ISO and USP as the primary method for measuring the size and number of particles in a …

Jun 2, 2025 · Particulate matter can be tested using two different methods: the tiny particle count test and the light-obscuration particle count test. Except in cases where preparations are too …

Based on the principle of light obscuration, this test allows for automatic determination of the number of particles according to their size. The test is performed in a biological safety cabinet, …

LIGHT OBSCURATION PARTICLE COUNT TEST. This test applies to ophthalmic solutions, including solutions constituted from sterile solids, for which a test for Particulate matter is …

Light Obscuration Particle Count Test (Method 1) We use the HIAC liquid particle counter system to test parenteral products for sub-visible particle content using light obscuration.

Light obscuration or the reduction of light intensity is measured by the detector. The detector will then process the measured signal and use it to display a comprehensive calibration curve. …

USP presents two different particle count test procedures – light obscuration and the microscopic particle count test. This post will focus on a visual illustration of the latter method.

Light Obscuration Particle Count Test is used to examine injections and parenteral infusions for subvisible particles, other than gas bubbles, unintentionally present in the product.

The large diameter droplet tails (PFAT5) is measured using a light obscuration/extinction liquid particle counter that employs the single particle optical sizing (SPOS) technique.