How companies have developed new types of hard capsules to overcome special challenges posed by dry powder inhalers.
Almost 40 years ago, Fisons Pharmaceutical Division introduced the Spinhaler device, making it the first company to use a hard gelatin capsule as a single dose container for inhalation powders in a dry powder inhaler (DPI). The first Spinhaler capsules contained 40 mg of an equal part mixture of lactose and sodium cromolyn (SC) (sodium cromoglicate BP), used for the prophylactic treatment of asthma. This novel delivery method used the two-piece capsule in a completely new way and presented a new challenge for pharmaceutical scientists: the need to open the gelatin capsule in some way to release the powder into the patient’s inspirational air stream.