The chemical stability of oxygen, moisture or light sensitive drugs can be significantly improved by using liquid or semi-solid capsule products.  The stability of oxygen sensitive compounds in the crystalline state is poor due to oxygen/ air being trapped in the crystal lattice.  By dissolving the drug in non-aqueous vehicles which are compatible with capsules, this problem of instability can be eliminated.  Similarly, the amount of moisture present in tablet or powder based formulations can be 10-100 times greater than in the oil or lipid based formulations that we use at Encap.  This can also have a significant impact in improving drug stability.

Vancomycin is one product that was successfully developed as a liquid fill capsule product in order to achieve acceptable stability.