DISPERSION PROCESS: ROLE IN THE FORMULATION OF PARTICULATE DISPERSE SYSTEM OF POORLY SOLUBLE DRUGS

Abstract

As significant number of products manufactured for personal care/health care, either in the final stage or at some stage of their production, dispersion of particulate materials dispersed into liquid or solid vehicles, often at high volume fraction. The vast array of cosmetics/personal care and pharmaceutical products reveal the importance of adequate dispersion. With active pharmaceutical ingredients possessing poor aqueous solubility, optimal dispersion is necessary for maximizing the bioavailability and uniformity of dose. Fine particulate dry powders always contain agglomerates that require de-agglomeration and stabilization to obtain optimal dispersion. All particulate dispersion systems are inherently thermodynamically unstable. Unless properly stabilized, through the random motion of the particles over time, they will get aggregate due to the natural and dominant tendency to decrease the large specific surface area and excess surface energy. Adequate concentrations of wetting agents, de-agglomerating agents and stabilizers are required to produce stable particulate dispersions. The dispersion process is accomplished via three distinct steps: wetting the particulate material, de-agglomeration of the particles and stabilization of the same, and these steps should be performed in the correct order to get a stable product.

Key words: de-agglomeration, stabilization, Ostwald ripening, particulate dispersion, aggregates.