Pharmaceutical Clients Clamoring For WWII-era Average Particle Diameter Testing

The Model 95 Fisher Sub-Sieve Sizer is an odd sight in PTL's collection of state of the art, computerized particle testing equipment. Built on a particle testing technique dating at least to the 1940s, the instrument's wood housing, rubber tubing and analog manometer for fluid pressure measurement may inspire more nostalgia than technical confidence at first glance.

But lately, it seems the pharmaceutical industry can't get enough of this classic particle testing technique. PTL clients are increasingly requesting testing via FSSS per current ASTM, ISO and USP methods. The Sub-Sieve Sizer tests powders quickly and reproducibly for their Average Particle Diameter - also known as the Air Permeability Diameter.

The analytical technique determines the average particle size by measuring the pressure drop across a packed powder bed using a water manometer. The pressure drop is a function of the permeability of the packed bed. This is related to the surface area of the particles which is then transformed to an "average size" based upon the assumption that the particles are spherical. The disadvantage of the technique is that it does not report on the statistics of the size distribution.

PTL's philosophy is to provide as many lab options as the client needs, and that ensures that the best techniques - modern and classical ones such as the Fisher Sub-Sieve Sizer alike - are readily available to provide insight into client projects.

Industries Served

Abrasives Serving the abrasive industry over the last 2 decades, the most common testing performed for this field is particle size and shape analysis. The world of abrasives can encompass a host of varying...
Dietary Supplements Concurrent with the U.S. Food and Drug Administration’s final rule establishing regulations to require current good manufacturing practices (cGMPs) for dietary supplements, PTL can offer cGMP services...
Environmental Testing Services Particle size, particle concentration and other physical characterization analyses are critical to many environmental applications. Regulatory agencies in the environmental sphere demand strict compliance...
Medical Devices Advances in biomedical implant and device technology continue to present new challenges in the area of physical testing. Particle Size Distribution, Surface Area and Porosity measurement data are...
Pharmaceutical Testing Services Supporting drug development with pharmaceutical testing is some of the most exciting work we do. As a premier cGMP contract service laboratory, PTL partners with pharmaceutical scientists to identify...
Beauty / Cosmetics Testing PTL’s analytical staff has years of experience designing test methods and performing analysis for cosmetic, skin care, fragrance and personal hygiene samples. Whether your company needs a third...