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Biomedical subjects

J D Buehler

Publications and source records attributed to J D Buehler.

4 recordsLinked to original sources
PubMed1982

Evaluation of antacid suspensions containing aluminum hydroxide and magnesium hydroxide.

Liquid antacid suspensions containing aluminum hydroxide and magnesium hydroxide were evaluated for composition, antacid properties, and product quality. The equivalent aluminum oxide and magnesium hydroxide content was determined by chelatometric titration, and sodium content was determined by flame photometry. Antacid properties measured were acid-consuming capacity, antacid effectiveness (preliminary antacid test, acid-neutralizing capacity test), and pH-stat titration. Content uniformity, consistency of the antacid properties, and microbiological content were examined for each product. Data are presented for 36 products for which samples from four or more lots were obtained. The ratio of percentage of equivalent aluminum oxide to percentage of magnesium hydroxide ranged from 1:0.6 to 1:3.5; this range allows for selection of the desired balance between the laxative effect of magnesium hydroxide and the constipating effect of aluminum hydroxide. Based on a daily dose of 280 meq of antacid, the sodium content of the products tested ranged from less than 2% to approximately 45% of the 500 mg per day of sodium allowed in a sodium-restricted diet. The concept of bioavailability was related to the amount of the antacid reacting at pH 3, 37 degrees C during the estimated gastric residence time of 15 minutes. Antacid suspensions are available which will react almost completely (neutralizing greater than 90% of the theoretical quantity of acid) during the estimated gastric residence time. Approximately 4% of the samples contained unacceptable numbers of bacteria. An antacid suspension cannot be adequately evaluated by a single test; choice of a product should be based on an evaluation that integrates several characteristics including sodium content, time and volume required to neutralize a given amount of acid, and uniformity of content.

Aluminum Hydroxide↗
PubMed1976

Correlation between dissolution characteristics and absorption of methaqualone from solid dosage forms.

A methaqualone tablet in two strengths, 150 and 300 mg, was developed. The dissolution rate of an experimental formulation in pH 7.0 phosphate buffer, measured by the resin flask method, was shown to correlate with bioavailability in humans. The dissolution rate criterion was used to develop the final tablet formulation. Bioavailability of this formulation in two strengths was compared with a commercial capsule formulation and a slowly dissolving tablet formulation. Correlation between dissolution rate and bioavailability was shown in freshly prepared methaqualone tablet formulations. Bioavailability of tablets under accelerated stability testing conditions remained unaltered, whereas the dissolution rates in pH 7 phosphate buffer decreased, using the resin flask method. A rotating-flask method was developed, and dissolution in 0.1 N HCl at 2 rpm correlated with the bioavailability of both new and aged tablet formulations.

Absorption↗