Mechanical Characterization of Pharmaceutical Powders by Nanoindentation and Correlation with Their Behavior during Grinding.

Controlling the size of powder particles is pivotal in the design of many pharmaceutical forms and the related manufacturing processes and plants. One of the most common techniques for particle size reduction in the process industry is powder milling, whose efficiency relates to the mechanical properties of the powder particles themselves. In this work, we first characterize the elastic and plastic responses of different pharmaceutical powders by measuring their Young modulus, the hardness, and the brittleness index via nano-indentation.

Combining formulation and process aspects for optimizing the high-shear wet granulation of common drugs.

The purpose of this research was to determine the effects of some important drug properties (such as particle size distribution, hygroscopicity and solubility) and process variables on the granule growth behaviour and final drug distribution in high shear wet granulation. Results have been analyzed in the light of widely accepted theories and some recently developed approaches. A mixture composed of drug, some excipients and a dry binder was processed using a lab-scale high-shear mixer.

Comparison of performance of high-performance liquid chromatography columns packed with superficially and fully porous 2.5 μm particles using kinetic plots.

A recently introduced 2.5 μm fully porous support (Kromasil Eternity) is compared with three different brands of superficially porous material (Kinetex, Halo and Poroshell 120) by means of the kinetic plot method using pharmaceutical compounds from GlaxoSmithKline as probe molecules. The kinetic plot method immediately shows the range of plate numbers wherein a support performs better than another.

Relationship between the particle size distribution of commercial fully porous and superficially porous high-performance liquid chromatography column packings and their chromatographic performance.

The separation efficiency and kinetics of several commercial HPLC particle types (both fully porous and superficially porous) have been investigated using a pharmaceutical weakly basic N-containing compound as a test molecule. A strong trend between the particle size distribution (PSD) of the particles and the typically employed "goodness of packing"-parameters was observed. The relative standard deviation of the PSD of the tested particles ranged between 0.

Kinetic performance of reversed-phase C18 high-performance liquid chromatography columns compared by means of the Kinetic Plot Method in pharmaceutically relevant applications.

Four fully porous C18 columns (Hypersil Gold, ACE3, Xbridge and Gemini NX), widely employed in the pharmaceutical industry, were compared in terms of efficiency and analysis speed with the Kinetic Plot Method. Weakly basic, medium-sized, N-containing pharmaceutical compounds from GlaxoSmithKline Research and Development were used as test molecules. Isocratic elution was carried out at pH 4.

Formulation design for optimal high-shear wet granulation using on-line torque measurements.

An alternative procedure for achieving formulation design in a high-shear wet granulation process has been developed. Particularly, a new formulation map has been proposed which describes the onset of a significant granule growth as a function of the formulation variables (diluent, dry and liquid binder). Granule growth has been monitored using on-line impeller torque and evaluated as changes in granule particle size distribution with respect to the dry formulation.