Drug-excipient interactions resulting from powder mixing. IV: Role of lubricants and their effect on in vitro dissolution

• Published in: Journal of pharmaceutical sciences Vol. 75; no. 6; p. 542
• Main Authors: Chowhan, Z T, Chi, L H
• Format: Journal Article
• Language: English
• Published: United States 01.06.1986
• Subjects: Chemistry, Pharmaceutical; Excipients; Kinetics; Lubrication; Microscopy, Electron, Scanning; Particle Size; Pharmaceutical Preparations - analysis; Powders; Solubility
• ISSN: 0022-3549
• DOI: 10.1002/jps.2600750604

Two lubricants, magnesium stearate and sodium stearyl fumarate, were compared under identical mixing conditions to study their roles in drug-excipient interactions. After prolonged mixing, sodium stearyl fumarate did not interact with the drug or excipients; as a result, the disintegration time and drug dissolution rate from hand-filled, uncompacted capsules were not adversely affected. In contrast, magnesium stearate did exhibit drug-excipient interactions which resulted in lamination and subsequent adhesion of the lubricant to the drug-crospovidone agglomerates. These interactions adversely affected the disintegration time and drug dissolution rate from hand-filled, uncompacted capsules. Although the initial specific surface area of magnesium stearate was higher than that of sodium stearyl fumarate, flaking of magnesium stearate due to particulate-particulate interactions caused a large increase in the surface area. The adhesion of the magnesium stearate flakes to the drug-crospovidone agglomerates resulted in a decrease in the drug dissolution rate.