Numerical Simulations on Mixing Dynamics of Spherical and Non-Spherical Tablets in a Pan Coater

Discrete element simulations provide valuable insight into the mixing dynamics of granular materials in industry. In this paper, numerical work is conducted in order to find the influence of pan rotational velocity and particle shape on mixing behavior. Four types of particles of different shapes were chosen: spherical, non-spherical type 1 (disk shape), non-spherical type 2 (capsule shape), and non-spherical type 3 (triangular shape). The pan mixer was filled with ~ 30 % volume of the same shape with the particles and was rotated at 15 RPM, 30 RPM, 45 RPM, and 60 RPM. The particles were colored as bottom-particles, middle-particles, and top-particles in order to visualize mixing efficiency. The homogeneity of the mixtures was determined by using contact dynamics of particles. The results show that fast-rotating pan (30-60 RPM) provides good mixing for all shapes of particles. However, non-spherical particles do not show as good mixing as spherical particles.

Optimization and In-vitro Evaluation of Coating Process for Film-Coated Tablets

The proper efficiency of the tablet-coating process often results in a coating within adequate quality, which might avoid the rejection of the film-coated tablets, minimize the operating expenses and production time. In general, the optimum coating system performance and coating conditions are important for achieving the desirable tablet-coating uniformity and manufacturing reproducibility. In this study, HPMC-aqueous-based tablet film coating successfully conducted in a perforated pan coater for process scale-up using the spray-coating technique. Certain process parameters such as spray rate, inlet air temperature, pan temperature, atomizing pressure as well as pan speed were maintained carefully and the optimum coating quality was achieved with acceptable film performance. At lower initial pan speed, the strength of the coated tablets was remarkably improved and the highest weight gain obtained. The smoothest and uniform film obtained at high spray rate, high pan speed, and low atomizing pressure. The results revealed that the optimum film-coating quality and uniformity achieved at a spray rate of 480 ml/min, atomizing pressure at 5 bar, inlet temperature at 85 to 90 °C, pan temperature at 58 °C, initial pan speed at 1.5 rpm and final pan speed at 4.0 rpm using side-vented pan coater. At initial pan speed of 1.5 rpm, the strength of the coated tablets remarkably improved with minimum edges erosion, which increases the weight gain up to 3.3%w/w.