Liquid Dosage Best Practice: Measuring Viscosity of Small Samples

Formulating new products in the pharmaceutical world oftentimes requires working with small sample volumes. Therefore the viscosity measurement method requires an apparatus that can work effectively with limited amounts of material. Quality Control may also need to implement this same test procedure, so it makes good sense to choose a device that can be easily used by both QC technicians as well as R&D personnel.

The most popular choice has been the cone/plate method because it works with sample sizes on the order of 5mL or less. In fact, many of the sample volumes required, depending on the cone spindle used, can be 0.5mL which is ideal when limited amounts of sample material are available. The second advantage of this test system is the broad range of shear rates that can be applied in testing the sample material. So let’s provide a clear picture of what is involved in using cone/plate equipment.