Quality-control analytical methods: considerations in compounding peroral solid dosage forms

Pharmacists who are engaged in drug compounding have specific guidelines and standards that are outlined in the United States Pharmacopeia-National Formulary. Of the many dosage forms that are available for the compounder, capsules and tablets (peroral solids) represent the most stable and convenient formulations for drug combinations. Dosage units must remain consistent, and the uniformity of dosage units should be demonstrable. Specific standards for the uniformity of dosage units are outlined in United States Pharmacopeia Chapter 905, which was developed specifically for the pharmaceutical industry. The uniformity of dosage units can be demonstrated by either of two methods, Content Uniformity or Weight Variation. Weighing and blending activities are critical in compounding. Therefore, all efforts should be expended to prevent errors in weighing and other steps that could adversely affect the final preparation.