abstract |
The present invention provides a base for coating a solid enteric pharmaceutical preparation whose dissolution pH ranges from 3 to 4. The coating base is a cellulose acetate maleate which is prepared by substituting a water-soluble cellulose derivative with 0.25 to 0.5 acetyl group and 0.35 to 0.6 maleyl group per glucose ring of the cellulose derivative. The cellulose acetate maleate has a dissolution pH ranging from 3 to 4. |