Technical validation of a face mask adapted for dry powder inhalation in the equine species.

This research aimed to develop and validate different types of face masks for dry powder inhalation (DPI) therapy in horses, focusing on factors that affect successful medication delivery. The study found that mask design, specifically the presence of airtight seals and the positioning of the DPI device, significantly affected the efficacy of treatment.

Face Mask Evaluation and Experiment Setup

• This study worked with four different types of face masks, termed A-D.
• The research initially tested Mask A, which is a commercially available mask for metered-dose inhalation in horses. Mask B was structurally similar to Mask A but contained an added airtight seal between the mask and the horse’s head.
• Masks C and D were prototypes specifically adapted for DPI use. Both had an airtight seal and expiratory valves, but Mask D had the DPI device directly in front of one nostril, unlike Mask C which had the device between the nostrils.
• In the experiments, the researchers measured ‘inhalet emptying’ and ‘peak inspiratory pressure’ when conducted with each mask on five healthy horses. These parameters were paramount for determining dry powder delivery efficiency.

Results from Experimental Testing

• Results from the experiments showed poor inhalet emptying rates in Masks A and B. In contrast, masks C and D both displayed adequate negative inspiratory pressures, which led to significantly higher inhalet emptying rates.
• In a follow-up experiment, Masks C and D were leveraged to test the delivery of a drug called Ipratropium bromide in horses with chronic obstructive pulmonary disease (COPD).
• Results from this experiment showed a noticeable improvement in COPD symptoms in horses treated with Mask D, even with half the dosage compared to Mask C. This highlighted the importance of the DPI device placement.

Conclusions Drawn from the Study

• The success of inhalet emptying – essentially the delivery of the medication – is strongly tied to the inspiratory pressures achieved in the masks, which is determined by the masks’ airtightness.
• The DPI device’s placement directly in front of a horse’s nostril could enable bronchodilation with a lower drug dosage than required when placed between the nostrils.
• The study concluded that DPI using Mask D (marketed as EquiPoudre) is a swift, effective, and well-tolerated treatment approach for horses affected by COPD.