Electrical conductance of directly compressible materials under pressure.

An electrometer that allowed direct recording of resistance changes during compression was used to measure the conductances of sodium chloride, potassium chloride, ammonium chloride, and sodium citrate. The effects of initial particle size, lubricant level, moisture content, and compaction pressure were determined. Direct compression tableting diluents also studied were dextrose, sucrose, lactose, microcrystalline cellulose, and dibasic calcium phosphate. Distinctive conductance patterns were observed and are rationalized in terms of previously proposed bondign machanisms.