Identification and Optimization of Parameters Affecting and Active Drug Coating on Core Tablets

Abstract

Active film coating is a process that enables uniform film formation on the surface of core tablets by spraying the coating liquid containing an Active Pharmaceutical Ingredient (API) dissolved or dispersed in coating material. The main objective of study was to identify the critical parameters that affect active coating on core tablets and to evaluate content uniformity of the API coated tablets. The target % RSD value was less than 6% and acceptance value was less than 15. Round and oval shaped tablets with two different weights 200 mg and 600 mg were taken and the influence of shape and weight on active coating was determined. Model drug was chosen as an API to be coated on the placebo core tablets and HPMC E5 was used as a film forming polymer. Pan load was optimized in the preliminary trials while spray rate and pan rpm was optimized using 32 full factorial design using Design Expert (9.0.4) software with % RSD and % CPE as dependent variables. The droplet size and droplet size distribution were analyzed using optical microscope to show the interaction and behavior of spray on core tablet surface. The results showed that round shape tablets were preferred over oval shape tablets. In particular round 200 mg tablets were the first choice of shape to be used for active film coating followed by oval 200, round 600 and oval 600 tablet. To ensure success in film coating process design (i.e. shape) of tablet along with formulation should be considered early in the development. Active drug coating also provides industrial application in tablet production of low dose API as well as in preparing fixed dose combination tablets (immediate release API can be coated on the core tablets having modified release profile). It was suggested to use a side vented perforated coater to develop a coated tablet product containing an active agent in the film coat.