Shell and capsule technology

The shell is plant-based and built on pullulan rather than on gelatin or on cellulose ethers. Gelatin is animal-derived, which a number of customers exclude on principle, and gelatin shells are prone to cross-linking during storage, which slows release over shelf life in exactly the way a rapid-release product cannot tolerate.

Cellulose ether shells generally rely on a secondary gelling agent, and those systems are sensitive to the ions present in mineral and electrolyte fills, which can delay opening. A pullulan-based shell releases consistently and is not affected by the ionic content of the fill.

The shell is specified against a water disintegration test, with full disintegration inside 60 to 90 seconds. Rapid disintegration matters because equine gastric transit is quick and a shell that opens slowly risks passing on before the contents are released. Disintegration time is governed by wall thickness, shell composition and the disintegration medium, and it is checked as a release test on every batch.

The capsule is designed to be given with a standard equine dosing gun. The profile is smooth and fully radiused with no flat edges or seams that could catch, and the shell has enough rigidity to be held and released by the plunger without deforming. The band seal keeps the two halves together under the load of administration.