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Granules have been prepared using a hydrophobic powder and a modified starch as binder. Granules suitable for tabletting couid De prepared using either water and 25% modified starch or a surfactant solution and not less than 5% modified starch. Compacts produced from a coarse size fraction of these granules disintegrated readily only if the granulation liquid contained surfactant. All compacts had adequate strength to withstand handling but those containing surfactant were weaker.

Polymer films have been prepared using four tablet binders, lactose, sodium lauryl sulphate and polyethylene glycol 600 have been used as inclusions in the films. The films have been tested to failure in tension and stress/strain diagrams have been prepared for each system examined. Granules and compacts have been prepared using the polymers as binders with, and without, the inclusions. The substrate for the granules was sand to eliminate the effects of solubility. Granules have been examined for size, friability and strength; compacts have been made when possible and tested for strength. The strength of bonds, between glass plates, has been measured using a butt-joint test.The inclusions resulted in a reduction of the ultimate tensile strength of all the binder films. PEG 600 had little plasticising effect, sodium lauryl sulphate and lactose both made some films of PVP and Starch too brittle to test. Effects on bond strengths varied with film/inclusion combination.The inclusions weakened the granules but had little effect on friability. Compact strengths were reduced by the inclusions except for lactose combined with either gelatin or starch.

A Planetary mixer has been modified so that the conductivity of the damp mass could be studied during the process of wet-massing in granulation. The technique makes it possible to follow the distribution of the binder liquid and possibly also the changes in packing that occur during massing.