By Bob Bruno, Life Science Leader magazine
Many new and advanced drug (and vaccine) formulations that could effectively treat human and veterinary diseases may never make it beyond the laboratory. Three common problems exist with these drugs: a) limited bioavailability (the rate at which the active drug enters the systemic circulation, making it difficult for the body to adsorb), b) issues concerning the safe and efficient delivery of the drug into the circulatory system, and c) the toxicity level of the drug.
Drug formulations that attempt to overcome these limitations exist as liposomes, emulsions, or suspensions, the latter consisting of solid nonsoluble active pharmaceutical ingredients (APIs) suspended in a liquid. The size of the API particles determines the stability of the formulation. If the particles are too large or are nonuniform in size, they will no longer remain suspended in the liquid and will prematurely settle out, rendering the formulation unusable.