The adhesion of film coatings to tablet surfaces--instrumentation and preliminary evaluation.

The strength of the adhesive bond between a film coating and a tablet surface has been studied using a specially designed tensile testing apparatus. The adhesion has been taken as the force required to remove the film from unit area of the tablet surface and has been shown to be dependent on the compression pressure used to prepare the tablet and on changes in the film formulation. Although plasticizers did not show any significant effect on the adhesion of a hydroxypropyl methylcellulose film, a reduction of 45% was found on the addition of 10% w/w titanium dioxide.