Studies Relating to the Content Uniformity of Suppositories. Part One: Use of Lactose as A Drug Carrier to Hinder Sedimentation

Abstract

Little attention has been given to the content uniformity of dispersed solid drugs in suppositories. Problems like sedimentation and/or incomplete dispersion of drug agglomerates may result in poor content uniformity, particularly when drug is formulated in minute amounts. Addition of lactose, as an inert carrier to a drug, at an optimal drug-carrier ratio has shown to improve content uniformity of suppositories. Time of mixing is another parameter which has also been optimized. In addition to the coefficient of variation a sedimentation Index ‘SI’ has been proposed as in-process control parameter to evaluate the content uniformity of suppositories. Value of unity for ‘SI’ indicates absence of sedimentation; a problem which is mainly encountered with mixing of solids in liquids or melted suppository bases