ADHESION AND AUTOADHESION MEASUREMENTS OF MICRONIZED PARTICLES OF PHARMACEUTICAL POWDERS TO COMPACTED POWDER SURFACES.
CHEM PHARM BULL
Micronized samples of lactose monohydrate and salmeterol xinafoate have been used to study the adhesion of micronized particles to compacted powder surfaces, After an initial increase in median adhesion force with increased press-on force no further increase in median adhesion force can be achieved, Thus application of larger press-on forces eventually appears to result in a maximum plastic deformation of the micronized particles, This is in contrast to previous experiments using particles of the same materials in a size range between 20 and 120 mu m, where an increase in press-on force always led to an increase in median adhesion force.The adhesion of micronized lactose monohydrate particles to salmeterol xinafoate surfaces is numerically higher than the adhesion of micronized salmeterol xinafoate particles to lactose monohydrate surfaces, although theoretically the same two materials are adhered to each other, This effect could be due to differences in the surface roughness of the compacted surfaces, Hence, if a true estimate of adhesion is required from adhesion studies of any two materials, either material should be used as particulate and as compacted powder material. Otherwise a careful consideration of the practical conditions which are to be modelled has to be made to choose the most appropriate system.The relative autoadhesion force of micronized lactose monohydrate particles could have been predicted from the results obtained using larger particles, This is valid with small limitations also for the relative autoadhesion force of salmeterol xinafoate. The relative adhesion force of salmeterol xinafoate particles to compacted lactose monohydrate surfaces appears independent of particles size even into micronized size range if particles with similar morphology are compared.
|Title:||ADHESION AND AUTOADHESION MEASUREMENTS OF MICRONIZED PARTICLES OF PHARMACEUTICAL POWDERS TO COMPACTED POWDER SURFACES|
|Keywords:||ADHESION, AUTOADHESION, CENTRIFUGE TECHNIQUE, MICRONIZED PARTICLE, PARTICLE MORPHOLOGY, SURFACE ROUGHNESS, COMPRESSION, SUBSTRATE|
|UCL classification:||UCL > School of BEAMS > Faculty of Engineering Science
UCL > School of BEAMS > Faculty of Engineering Science > Mechanical Engineering
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