Determination of factors that affect the generation of airborne particles from bulk pharmaceutical powders

Chetan Pratap Pujara, Purdue University

Abstract

The purpose of the present study was to determine the physical parameters of powders that govern the aerosolization of bulk powders. While this investigation has many applications in the pharmaceutical industry, this work specifically addresses powder dustiness. Dustiness is defined as the propensity of a material to emit dust (aerosolize) during handling operations. The handling of powders and granulated solids generates airborne dust that may affect worker health and safety, cause a nuisance and/or result in product loss. The methods of preventing dust generation are of increasing importance in handling of powders, due to the growing emphasis on health and safety by the Food and Drug Administration. Dustiness studies on pharmaceutical powders are very sparse in the literature and clearly a study in this area would be valuable and would contribute to further research in this field. The Heubach Dustmeter, a commercially available instrument, was used to investigate powder dustiness. Eighteen commonly used pharmaceutical powders were selected for this study. A 10 gm sample studied at an airflow rate of 10L/min was found to be ideal for dustiness tests of pharmaceutical powders. The effects of particle size and size distribution, particle shape, particle density, moisture content, powder porosity and surface area, on the generation of airborne particles from the powders were determined. A classification scheme has been developed based on the particle size distributions of the powder and the dust generated from the powder. It was found that the median particle size of a powder was insufficient in predicting the dustiness of powders. A model consisting of a novel shape coefficient and particle size is presented which can be used to estimate the extent of dry powder aerosolization. It was found that low quantities of excipients may be mixed with powders to produce systems for lower dustiness. Finally, timelines for establishing exposure control limits of potent powders in the pharmaceutical industry have been suggested. The results presented may be valuable to pharmaceutical industries that manufacture and use pharmacologically potent powders in understanding the potential harm that a potent powder can cause to the workers and the environment.

Degree

Ph.D.

Advisors

Kildsig, Purdue University.

Subject Area

Environmental science|Pharmaceuticals|Pharmacology

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