THE MECHANICAL AND ADHESION PROPERTIES OF AQUEOUS-BASED HYDROXYPROPYLMETHYLCELLULOSE COATING SYSTEMS CONTAINING POLYDEXTROSE AND TITANIUM-DIOXIDE

The effect of titanium dioxide and polydextrose on film adhesion to mi crocrystalline cellulose tablet surface and mechanical properties of a queous-based hydroxypropyl methylcellulose free films were evaluated u sing a Lloyd LRX materials testing machine. The free films and the fil ms applied to tablets were prepared by using a pneumatic spraying tech nique similar to that used in fluidized-bed coaters. The film adhesion was found to increase with increasing concentrations of titanium diox ide and polydextrose in the film. The addition of polydextrose to the film increased only slightly the moisture permeation of coated tablets . This may be due to the hygroscopic nature of polydextrose. Over the range studied, the addition of polydextrose reduced the elongation and the tensile strength of the film, indicating decreased deformation ca pacity of the film and a risk of cracking.