Stability of repackaged dabigatran etexilate capsules in dose administration aids

This study is aimed at assessing the stability of dabigatran etexilate (Pradaxa) capsules repackaged into a dose administration aid (DAA), in order to inform appropriate storage conditions that ensure quality. Although Pradaxa is used chronically by patients, and DAAs are known to improve adherence, removal of the capsules from their original packaging is not recommended by the manufacturer due to sensitivity to moisture.

Pradaxa capsules containing dabigatran etexilate 110 mg were repackaged into a commercially available DAA and stored under ambient conditions (30°C±2°C and 75%±5% relative humidity) for periods of 14 and 28 days and in a domestic refrigerator for 28 days. The capsules were evaluated for changes in their physical appearance and weight. Content uniformity and the drug concentration during dissolution were determined using a validated high-performance liquid chromatography method.

Storage at ambient conditions for 14 and 28 days resulted in a percentage drug remaining of 92.5% and 71.6%, respectively, indicating a lack of compendial compliance (88.4%-111.8%) for the 28-day ambient sample. There was a statistically significant difference (p=0.015) in the dissolution behaviour of the 14-day samples, when compared with control capsules. In contrast, repackaged capsules stored in the refrigerator for 28 days had a drug content of 98.2% and dissolution was not significantly affected (p=0.132).

This study has clearly demonstrated that if repackaging of Pradaxa capsules is required, storage under refrigerated conditions ensures quality for 28 days.