Thomas A Wheatley

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Drug contents of intact tablets were determined using non-destructive near infrared (NIR) reflectance and transmittance spectroscopic techniques. Tablets were compressed from blends of Avicel PH-101 and 0.5% w/w magnesium stearate with varying concentrations of anhydrous theophylline (0, 1, 2, 5, 10, 20 and 40% w/w). Ten tablets from each drug content batch(More)
The purpose of this study was to investigate the potential of two carrageenans, iota-carrageenan and lambda-carrageenan for the preparation of controlled-release tablets. Tablets were compressed on a Carver press and the effect of formulation factors, moisture, and storage on the release of theophylline was studied. The effect of sodium chloride in the(More)
This study investigates the potential of two commercial carrageenans, Gelcarin GP-379 (iota-carrageenan) and Viscarin GP-209 (lambda-carrageenan) to be used for the preparation of controlled-release tablet matrices. Tablets were compressed on an instrumented Stokes single punch machine and compression characteristics of the carrageenans were analyzed.(More)
The purpose of this study was to use near-infrared spectroscopy (NIRS) as a nondestructive technique to (a) differentiate three Avicel products (microcrystalline cellulose [MCC] PH-101, PH-102, and PH-200) in powdered form and in compressed tablets with and without 0.5% w/w magnesium stearate as a lubricant; (b) determine the magnesium stearate(More)
The objective of this work was to develop a method to assess the dilution capacity of direct compression excipients based on a technique previously proposed by Minchom and Armstrong (MA). The technique involves the addition of increasing quantities of a poorly compactible (compressible) material to the excipient and measuring the resultant decrease in the(More)
The objective of this study was to investigate the use of water soluble cellulose acetate (WSCA) as a film coating material for tablets. Aspirin (ASA) tablets were prepared by direct compression and coated with either WSCA or HPMC (hydroxypropyl methylcellulose) dispersions. Coatings of 1-3%, depending on the intended application, were applied to the model(More)
The rate and extent of acid consumption of an antacid suspension and tablet were evaluated by in vitro and in vivo techniques. Four different test procedures were used to estimate in vitro antacid reactivity. In vivo effects were determined in the fasted and postcibal states in normal human subjects by a radiotelemetry procedure. The duration of elevation(More)
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