HARD CAPSULES MADE FROM HYDROXYPROPYL METHYLCELLULOSE AND METHOD OF PRODUCING SAID CAPSULES Russian patent published in 2011 - IPC C08B11/193 A61J3/07 A61K9/38 

FIELD: chemistry.

SUBSTANCE: composition contains 15-25 wt % hydroxymethyl cellulose per total weight of the aqueous composition. Hydroxypropyl methylcellulose contains 27.0-30.0% (wt/wt) methoxy groups and 4.0-7.5% hydroxypropoxy groups and has viscosity of 3.5-6.0 Sp in form of 2 wt % solution at 20°C. The method of producing hard capsules from hydroxypropyl methylcellulose by via dip coating involves preparation of an aqueous composition, preheating the dipping rods, immersing the preheated dipping rods into the aqueous composition, removing the rods from the composition and drying the film on the dipping rods. The dipping rods are preheated to 55-95 °C. Temperature of the aqueous composition during immersion of the dipping rods is kept 10°C-1.0°C below its gelling temperature. The obtained shell of the hard capsule contains hydroxymethyl cellulose in amount of 70-99% of the weight of the shell.

EFFECT: obtained capsules have high transparency, excellent solubility and good mechanical characteristics.

16 cl, 2 tbl, 9 ex