Biomedical subjects

N Pilpel

Publications and source records attributed to N Pilpel.

At least 55 records · Page 3Linked to original sources

PubMed1977

The action of colloidal silicon dioxide as a glidant for lactose, paracetamol, oxytetracycline and their mixtures.

Anomalies are observed in some of the physical and mechanical properties of mixtures of lactose, paracetamol and oxytetracycline when small amounts of colloidal silicon dioxide are added to them. Owing to its differing propensities to coat the particles of the host powders, the silicon dioxide acts as a glidant for the lactose and paracetamol, but as an antiglidant for the oxytetracycline.

Acetaminophen↗

PubMed1977

Moisture and gelatin effects on the interparticle attractive forces and the compression behaviour of oxytetracycline formulations.

The tensile strengths of compacts and/or tablets of the individual components and of granules prepared from an oxytetracycline formulation have been measured using the diametral compression test. Employing the theory of tensile strength, proposed by Cheng, it has been shown that increases in both moisture and gelatin contents of compacts and tablets increase the range of the attractive forces that operate between the granules. By studying the effects of moisture and gelatin on the compressional behaviour of the granules, it has been possible to classify them into different types. Fragmentation of granules occurs at packing fractions between 0-745 and 0-835, depending on their gelatin content.

Drug Compounding↗

PubMed1977

The effect of temperature on the tensile strength and disintegration of paracetamol and oxytetracycline tablets.

The tensile strengths and disintegration times of paracetamol and oxytetracycline tablets at room temperature are higher when they have been prepared at high temperatures, e.g. 85 degrees, than at room temperature or below, e.g.--20 degrees. The activation energies of the two materials, 3 and 1 k cal mol-1 (13 and 4kJmol-1) respectively, were derived from plots of log tensile strength and log disintegration time versus the reciprocal of the absolute temperature. The results have been explained in terms of sintering theory and the formation of welded bonds between particles.

Acetaminophen↗

PubMed1976

Some formulation factors affecting the tensile strength, disintegration and dissolution of uncoated oxytetracycline tablets.

A study has been made of the effects of gelatin binding agent and moisture content on the tensile strength, disintegration and dissolution times of oxytetracycline tablets. These properties all increase with the gelatin content, and maximum tensile strengths occur when the tablets contain between 2.5 and 4.5% w/w of moisture. The properties of the tablets depend on their packing fraction and in general, the disintegration and dissolution times are minimal when the packing fraction is between 0.77 and 0.82. A connection has been established between the disintegration times of the tablets and the time required for 50% of the drug content to dissolve.

Drug Compounding↗

PubMed1976

Anomalies in some properties of powder mixtures.

Mixtures of lactose and paracetamol and of lactose and oxytetracycline exhibit anomalous properties. The mean particle sizes, tensile strengths and flow properties of the mixtures are not proportionally intermediate between those of the constituents. The results are ascribed to changes that occur in the packing arrangements of the particles. These changes could have practical consequences in monitoring the progress of a mixing operation by measuring apparent particle size and in controlling the properties of granules, capsules and tablets prepared from the mixtures.

Acetaminophen↗

PubMed1974