What is Curing condition in coating tablet process? Curing is as thermal treatment following the application of coat.

The coalescence of colloidal polymer particles from the aqueous coating dispersions is usually incomplete. As a result coalescence of particles during the storage temperature and time can occur which can in turn modify the release of drug from the coated products

To overcome this, curing which is a thermal treatment is followed. In this, the coated dosage forms are kept at elevated temperatures for short period of time. This promotes further coalescence of the polymer particles before the long term storage periods.

During the curing conditions the coated dosage forms are subjected to temperature higher than the glass transition temperatures of the polymer immediately after the coating is over. Usually curing temperature is about 10 C above the minimum film forming temperature (MFT). Very high curing temperatures can lead to excessive tackiness in the dosage form. Usual temperature for heat treatment is at 40°C for at least 4.5 hours.

Curing condition facilitated uniform distribution of plasticizers and improves polymer particle coalescence. Both retardation and increase in drug release can achieved depending upon the drug type and the curing conditions.