Measuring Volume, Density and Porosity of Tablets for Coating Process Control and QC

Many medicinal tablets are coated to improve in-vivo performance. Coatings are used to mask the taste of active pharmaceutical ingredients (APIs) and to control the location and rate of dissolution, to aid uptake, reduce side effects or prolong action via controlled release. As a result, coating integrity and thickness may be Critical Quality Attributes (CQA) […]

Analyzing Liquids with the AccuPyc

Introduction The AccuPyc is widely used for analyzing both solids and powders. Little information is readily available for using a pycnometer to analyze liquids. The AccuPyc measures pressure of the system to determine volume and calculate density. Pressure generated by sample evaporation can diminish precision and system equilibrium might not be obtainable. Vapor pressure is […]

Understanding the Uncertainty and Precision Specifications for AccuPyc

A frequently asked question is, “What is the accuracy of the densities reported by the AccuPyc?” And that is a good question. The problem is that, though the AccuPyc reports the skeletal density of the sample under test, it actually determines the skeletal volume, V, of the test portion. It uses the sample mass, M, […]

Determining the Open Cell Content of Rigid Cellular Plastics with the AccuPyc 1330 Pycnometer

Cellular plastics consist of thin polymeric membranes separating small cavities or cells. The cells may be mostly closed and separate, mostly open and interconnecting, or a combination of the two. The percentage of open cells is indicative of the insulating quality of cellular plastics and is an important variable, requiring control during manufacture and evaluation […]

Determining the Force or Pressure to Use for T.A.P. Bulk Density with GeoPyc 1360

To measure bulk density, the GeoPyc® 1360 consolidates the sample within a cylindrical chamber until a specific force is achieved. A measurement is taken at that point, and subtracted from blank (empty chamber) data stored in the GeoPyc to yield the sample’s bulk volume. This volume and the sample’s weight are used to calculate bulk […]

Measuring Volume, Density and Porosity of Tablets for Pharma Process Control

Volume, density, and porosity are interrelated parameters widely recognized as important for the control of drug product manufacture. Tableted medicines need to be a consistent size and shape for efficient packaging and patient acceptability. Envelope density can be a useful check of tablet consistency, since it may be influenced by the extent of compaction, while […]

Evaluating Catalyst Substrates with the GeoPyc® 1360

Critical factors in operating catalytic reactors are the envelope density and porosity of the catalyst itself.These properties are quickly and easily assessed with Micromeritics’ new GeoPyc 1360 in conjunctionwith Micromeritics’ AccuPyc™ 1330. Envelope density (sometimes called bulk density) is simply the weight of a quantity of catalyst divided bythe volume (including the pores) of the […]

Emulating Tap Density With T.A.P. Density on the GeoPyc

Conventional tap density analyzers obtain the volume of a material by lifting and dropping a graduated cylinder multiple times until the sample bed no longer compacts. This is a loud process that requires an operator to estimate the level on a graduated cylinder to the nearest tenth milliliter. The GeoPyc emulates conventional tap density analyzers […]

Attaining Envelope Density Reproducibility and Accuracy with Your GeoPyc

This application note contains guidelines for attaining reproducible and accurate envelope density measurements with your GeoPyc®. Reproducibility Achieving high reproducibility in any analytical measurement often requires performing tests in an identical manner using a single instrument, fixed instrument parameters, and the same quantity of test material. This is particularly true with the GeoPyc technique because […]

New Capability for the GeoPyc Makes Visible the Percent of the DryFlo Bed Occupied by the Sample

If too little sample is used with the GeoPyc® Envelope Density Analyzer, poor reproducibility of results will occur. The instrument is simply unable to distinguish between a DryFlo® bed with sample and one without sample when the sample volume occupies too small a percentage of the total bed. For optimum performance, the sample should occupy […]