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Biomedical subjects

C T Rhodes

Publications and source records attributed to C T Rhodes.

At least 73 records · Page 4Linked to original sources
PubMed1975

Disintegration properties of calcium phosphate dibasic dihydrate tablets.

The effect of compressional force on the disintegration time of tablets prepared from calcium phosphate dibasic dihydrate containing various tablet disintegrants was examined. The results show that effects of compressional force on disintegration time are of two types. The first type is that of insoluble disintegrants, e.g., starch and a cation-exchange resin, where the disintegration time initially shows a dramatic decrease. After this decrease, a further increase in compressional force appears to have no effect on the disintegration time. The second type is that of soluble disintegrants, e.g., calcium sodium alginate, sodium carboxymethylcellulose, and sodium staarch glycolate, where variation in compressional force has very little effect on the disintegration time. These results are discussed in terms of the differing mechanism whereby these substances act as disintegrants.

Alginates↗
PubMed1975

Effect of compaction on particle size.

Compressed tablets were prepared on a hydraulic press at several different compaction pressures by a standardized technique, using aspirin, dicalcium phosphate dihydrate, calcium phosphato-carbonate, alumina, and microcrystalline cellulose. All tablets except microcrystalline cellulose contained a cation-exchange resin as disintegrant. The particle-size spectra of the disintegrating compacts were evaluated using a particle-size counter or an air jet sieve. It is shown that compacts made from different materials but of the same initial particle-size spectra disintegrate to give particles of a considerably different size. Determination of the change in particle size produced by the compaction process provides useful insight into the nature of the compaction process.

Aluminum↗
PubMed1975

Water-sorption properties of tablet disintegrants.

The water-sorption properties of four tablet disintegrants, starch, sodium carboxymethylcellulose, sodium starch glycolate, and a cation-exchange resin, were examined in the form of powders and in compressed tablets prepared from calcium phosphate dibasic dihydrate. Dissolution properties of the tablets compare well to the water-sorption properties. The effect of storage in the presence of water vapor upon tablets containing the various disintegrants was evaluated in terms of tablet hardness and disintegration time. Differences in the effects produced in the various tablet formulations can be related to the differing mechanisms whereby the disintegrants effect tablet rupture. Photomicrographic data support the conclusions drawn from the water-sorption, disintegration, and dissolution studies. Sodium starch glycolate and the cation-exchange resin merit careful consideration by formulators using calcium phosphate dibasic dihydrate or similar direct compression matrixes.

Absorption↗
PubMed1975

Factors affecting the kinetic assay of nitroglycerin in dosage forms.

Parameters affecting the spectrophotometric kinetic assay for nitroglycerin are described. It is shown that the assay is highly specific; results are not significantly affected by many of the tablet diluents found in commercially-available nitroglycerin tablets. Further, the assay is insensitive to glycerol, nitrate, nitrite and glyceryl dinitrates. This simple, precise and specific nitroglycerin assay is well suited for routine analysis of the drug in commercial tablets and parenteral solutions in hospital pharmacies.

Chemistry, Pharmaceutical↗