The mechanical properties of some binders used in tableting

Abstract

Abstract Films of acacia, gelatin, methylhydroxyethyl cellulose, polyvinylpyrrolidone (PVP) and starch have been prepared with moisture levels of 2·0 to 20·0% w/w obtained by equilibration at relative humidities from 0 to 90%. Tensile strengths of 60 mm × 2 mm strips of these films have been determined by stressing to failure at a constant rate of 6·6 times 10−5 ms−1 in a tensile strength apparatus. From the stress-strain curves the modulus of elasticity, yield strength and the work done in breaking unit cross-sectional area of the films have been calculated. This has given an indication of the binders’ mechanical behaviour over the range of moisture contents likely to be encountered in tableting.