PubMed Health⌕ Search

Biomedical subjects

J R Britten

Publications and source records attributed to J R Britten.

4 recordsLinked to original sources

Studies on powder plug formation using a simulated capsule filling machine.

Using an apparatus which simulates the action of a Macofar 13-2 dosating-type capsule-filling machine, the variation in plug weight and density with changing machine parameters has been studied. The piston ejection speed has no effect on plug properties. However increase in compression speed leads to a less consolidated powder plug and hence reduced plug weight. Application of higher pressures reduces plug weight changes, but would be expected to affect release characteristics. Comparison of axial and radial pressures generated by plugs of Starch 1500 and lubricated lactose show significant differences which can be explained by the different consolidation and elastic properties of the two solids.

Drug Compounding↗

Construction of an intermittent-motion capsule filling machine simulator.

A pneumatically operated apparatus is described which simulates the forces generated by and the component movements encountered in a Macofar 13/2 dosator type capsule filling machine. Force transducers are fitted to the dosing piston and dosator tip, and the movement of the dosator piston and the powder bed followed by displacement transducers. Calibration of the transducers is described. The output from the transducers is collated, stored and manipulated by microcomputer. The manufacturing parameters which can be studied using this apparatus are discussed.

Calibration↗

Effects of temperature on the tensile strength of pharmaceutical powders.

Measurements have been made of the tensile strengths of fatty acids, lactose and of an oxtetracycline and a paracetamol tablet formulation at temperatures between -20 and +90 degrees. The measurements were made on compressed tablets and on consolidated beds of powders, using a diametral compression tester and a split plate tensile tester which had been designed to operate over this range of temperature. The tensile strengths of all the materials increase with temperature and values are given for the activation energies of bonding between particles.

Acetaminophen↗