Hard Capsules for Dry Powder Inhalers: Performance on Puncturing

The study presented describes the behavior of various dry powder inhaler (DPI) hard capsules under puncture, at different relative humidities (RH). Our objective was to study the puncturing force and holes morphology of gelatin, gelatin/PEG and hypromellose hard capsules when equilibrated at low RH and subjected to puncturing with a pin from commercial DPI device.