Performances of new generation of delayed release capsules

Objective: The purpose of this study was to verify the claimed acid-resistant properties and other performance indicators for AR Caps (Capsule 5 from CapsCanada) and DRcaps (Capsule 6 from Capsugel) and compare them with the immediate release hydroxypropyl methylcellulose "HPMC" capsules (K-CAPS from CapsCanada). Methods: Shell weight variability, reaction to different relative humidity conditions, empty shells response to stress under the absence of moisture, powder leaking, disintegration and dissolution properties were assessed. Results: Shell weight variability was highest among Capsule 4. At 45% RH and 23°C different types of capsules had similar loss on drying (LOD range: 5.23% - 6.68%). In the absence of moisture and following the application of a stress, empty Capsule 4 shells performed the best with the highest percentage of intactness of capsules (80%) followed by Capsule 6 (50%) and then Capsule 5 (20%). Both disintegration and dissolution test results for Capsule 4 deemed satisfactory for conventional release purposes, but Capsule 5 and 6 do not comply with the USP requirement for delayed-release dosage form. None of the tested capsules have the ability to protect hygroscopic encapsulated material from humid conditions as generally claimed. Conclusion: While HPMC capsule made for conventional release properties may be fit for that purpose, the new generation of capsules designed to protect the ingredient from the acid environment of stomach have not performed in such a manner as to comply with the USP requirements for disintegration and dissolution of delayed-release dosage form.