The Challenge

The client had a formulation which was a protein in an aqueous solution. Aqueous solutions are normally incompatible with capsules - they are designed or intended to dissolve in water. Drying the client's protein solution was highly likely to destroy the material. The client wished to test their active on rodents (rats) in enteric coated capsules. The challenge was to formulate aqueous material into a capsule-compatible formulation, without denaturing the protein.

The Solution

Fortunately the protein solution was to be diluted to achieve the target dosage, which allowed Encap to use its experience and patented know-how to devise a formulation which could hold a high level of water (30%), yet remained compatible and stable in hard shell capsules. Gelatin was the choice of capsules in this case but HPMC (Hydroxypropyl methyl cellulose) is an equally suitable alternative. Trials demonstrated the stability of formulation in capsules, and we could achieve the targeted accurately filled micro gram dosage.
Accurate dosing of microgram quantities is readily achievable by dilution of concentrate when all active materials are maintained in solution, unlike tablet or powder capsule manufacture, where uniform active distribution of microgram quantities, is a significant challenge.

The Outcome

The capsules required were size 9, which were to be accurately filled and enteric coated, this is a routine process at Encap for development scale batches. Active and placebo capsules are manufactured, tested and supplied to the client for their study.
Encap worked closely with the client to develop a viable formulation, without damaging/modification of their active model, so that it could be produced at commercial scale, with accurately filled dosage units which were suitable for the client's animal study. The project is ongoing.