Liquid Dose: Measuring Physical Properties

Pharmaceutical manufacturers have plenty to worry about when producing formulated products consistently within spec. Focus on active ingredients demands the greatest attention because the major investment cost is typically in this area. Other physical test parameters that cause concern for the marketing staff relate to product appearance, ease of handling, and mouth feel. These characteristics are best handled with conventional instruments like viscometers and texture analyzers, which quantify the forces associated with opening up a bottle of medicinal liquid, pouring it onto a spoon, and placing it in the mouth, or alternatively, extracting a gel cap from its wrapper and swallowing. Rather than relying on a staff of people who subjectively evaluate these phenomena, the pharmaceutical world has turned to instrumentation to do this testing.