Separation of Multisized Drug Suspensions into Narrow Distributions by Centrifugal Elutriation

• Published in: Journal of pharmaceutical sciences 1978-05, Vol.67 (5), p.673-675
• Main Authors: Howard, Stephen A., Mauger, John W., Khwangsopha, Aurawan, Lee, Ping
• Format: Article
• Language: English
• Subjects: Centrifugal elutriation-used to separate suspensions into distinct particle-size fractions; Centrifugation; Dosage forms-suspensions; Dosage forms—suspensions separated into distinct particle-size fractions by centrifugal elutriation; Hydrocortisone; Particle Size; Particle-size fractions-suspensions separated by centrifugal elutriation; Prednisolone; separated into distinct particle-size fractions by centrifugal elutriation; Solubility; Suspensions; Suspensions-separated into distinct particle-size fractions by centrifugal elutriation
• ISSN: 0022-3549; 1520-6017
• DOI: 10.1002/jps.2600670527

A centrifugal elutriator rotor was used to separate suspensions of micronized hydrocortisone acetate and prednisolone acetate. Up to five distinct particle fractions could be isolated from a single parent suspension, and reasonable reproducibility was exhibited between various elutriator runs. Arithmetic means and associated standard deviations, based on volume, were calculated for each isolated fraction. These data demonstrate the narrowness and uniqueness of each fraction. The particle-size data show an apparent log-normal distribution for each isolate. The uniqueness of each fraction also was demonstrated by dissolution experiments where Fraction 1, the smallest fraction of prednisolone acetate, dissolved much more rapidly than Fraction 4, the largest fraction. The substantial difference in dissolution behavior of these two fractions of prednisolone acetate powder was biopharmaceutically significant.