MEASUREMENT OF ELECTROSTATIC CHARGE DECAY IN PHARMACEUTICAL POWDERS AND POLYMER MATERIALS USED IN DRY POWDER INHALER DEVICES

The electrostatic charge generated oil drug/excipient particles during the formulation, manufacture, and use of pharmaceutical dry powder in haler (DPI) devices may significantly affect the performance of such d evices. An experimental investigation has been undertaken of charge ac cumulation and decay on compacts of selected powders (lactose and salb utamol sulfate) and a device material (polyvinyl chloride, PVC) used d uring the formulation, manufacture, and use of DPls. Significant diffe rences in charge acquisition and decay for the three materials have be en demonstrated after charging using a corona electrode. PVC acquired the highest charge, which decayed rapidly in 30 min toward the value p rior to exposure to corona. Lactose and salbutamol acquired similar ch arge values, which decayed to zero after 30 min for lactose, whereas s albutamol retained a significant charge after 120 min. The significant differences in charging propensity among drug, excipient, and device materials may have relevance in DPI formulation, manufacture, and use.