Thermal Sintering: A Novel technique in Formulation of Controlled Release Dosage form

Sintering is defined as the thermal treatment of a powder or compact at a temperature below the melting point of the main constituent, for the purpose of increasing its bond strength. This concept in pharmaceutical science is relatively new, but research works relating to this process have been growing. Sintering has been described as the mechanism for the strengthening of the mechanical properties of consolidated pharmaceutical powders at elevated temperatures, for solid-bond formation during tablet compression, and for thermal curing of polymer-latex film -Coatings. The changes in the microstructures, Hardness, Friability, Wettability, disintegration time and dissolution rate of tablets stored at elevated temperature were also described as a result of sintering. Controlled release oral dosage forms were developed by sintering the polymer matrix by exposing to temperature above glass transition (Tg) point of the polymer. In the application of thermal sintering technique to the formulation of controlled release dosage form, the main research focus has been on the influence of sintering on the alteration of the microstructures in a polymeric matrix and the release of the active ingredients from the matrix.