Richard J. Harwood

Transdermal delivery of drugs

An improved method for the topical administration of systemically or locally active drugs utilizes a bandage containing one or more layers including a drug useful in the treatment of disease and a heat-generating substance, each dispersed intimately throughout said bandage layers.

A Method of Coating Non-Uniform Granular Particles

AbstractA method was developed for coating non-uniform granular particles In a uniform and controlled manner. Specific surface area was calculated based on the sieve-analysis data of uncoated theophylline granules which was used as the model compound. Theophylline granules were coated with different amounts of Eudraglt® L30D utilizing a Wurster coating apparatus. The in-vitro dissolution rate profiles of several batches were determined. Standard dissolution curves were established based on the amount of Eudraglt® L30D applied per unit area of theophylline granules. Using these curves as a standard, a prediction of dissolution rate could be made based on the knowledge of specific surface area of the theophylline granules and the amount of coating applied.

Particle Morphology of Amorphous Aluminum Hydroxycarbonate and Its Effect on Tablet Production

AbstractThe particle morphology of amorphous aluminum hydroxycarbonate was studied by disaggregation induced by phosphate adsorption and direct observation by high resolution transmission electron microscopy. The primary particles are sheet-like and have equivalent diameters of 55A or less. The primary particles are believed to correspond to planar polymers comprised of six-membered rings of aluminum ions joined by double hydroxide bridges. Secondary particles form by attractive interaction of primary particles. The size of the primary particles affects the porosity of the secondary particles. The granulating and tableting properties of two spray dried amorphous aluminum hydroxycarbonates were shown to be related to the size of the primary particles and the porosity of the secondary particles.