Influence of Film Coating Process Parameters on the Gloss of Tablets Coated with Pigmented Aqueous Film Coating Formulations

Opadry® II 1 Influence of Film Coating Process Parameters on the Gloss of Tablets Coated with Pigmented Aqueous Film Coating Formulations PURPOSE A common practice for enhancing the gloss of coated tablets is the application of a clear top-coat after applying a pigmented coating layer. In a recent study, substantial increases in tablet gloss were achieved using this multiple step approach.1 It was also found that decreasing the solids concentration of the clear topcoat resulted in further improvements in gloss. In some cases it may be impractical or undesirable to utilize a two-step coating process. The purpose of this study was to examine the effects of coating process parameters and dispersion solids concentration on the gloss of tablets coated with single-step, pigmented, aqueous film coating formulations. The coating formulations and processes were evaluated on two different tablet dosage forms. METHODS The two substrates used in the study were multivitamin tablets (1000 mg) and placebo tablets (300 mg). The coating systems were Opadry II, high performance film coating systems, (PVA-based orange and yellow, Colorcon, Inc.). The trials (47 in total) were conducted in a 24” fully perforated pan (Labcoat II, O’Hara Technologies) equipped with two spray guns (VAU, Spraying Systems Inc.) to a target coating weight gain of 3.0%. A Design of Experiments (DOE) approach was used to evaluate the process variables of inlet temperature, airflow, spray rate, pan speed, and dispersion solids concentration (Table 1).