Electrostatic Characteristics of Pharmaceutical Solids and Packaging Materials I

The design and operating principles of an apparatus capable of measuring the inherent static charge on materials, as well as being able to induce a positive or negative electrostatic potential, are described. The dual polarity high voltage power supply unit of this instrument can apply up to 10,000 v. to the materials under study. The voltage accumulation or decay of the sample being evaluated in the modified Faraday cage of the apparatus can be read on the ammeter of the electrostatic voltage sensing pistol or displayed on an X-Y recorder from the sensing pistol. Measurements are reported on the relative static electrification tendencies of sodium chloride, stearic acid, sulfisomidine, and iodochlorhydroxyquin when exposed to negative and positive potentials of 6,000 v.