Duloxetine hydrochloride enteric-coated pellets in capsules with delayed release: formulation and evaluation

ABSTRACT The primary purpose of this study is to develop and evaluate an effective and reliable delayed-release dosage form of Duloxetine hydrochloride enteric-coated pellets in capsules. Duloxetine hydrochloride dissolves in an acidic environment, yet pellets maintain their enteric coating due to the Wurster expansion process for the Fluidized Bed Processor. Four distinct layers comprise enteric-coated pellets: a pharmaceutical layer, a barrier layer, an enteric layer, and a coating on the inert core pellets. A suspension layering approach protects the acidic environment from the drug by coating it with an enteric layer composed of hydroxyl propyl methyl cellulose phthalate HP55. We also determined the bulk and tapped densities, Hausner’s ratio, compressibility index, and moisture content of all formulations. The produced pellets are being evaluated for in-vitro release tests using UV-Visible spectroscopy. The zero-order model, the first-order model, and Higuchi’s square root equation, Hixson-Crowell, Korsemeyer peppas, and the Weibull model were used to evaluate the released kinetics models. Investigations using FT-IR (infrared spectroscopy) are still being undertaken to determine the drug’s compatibility with various excipients. Formulation ‘F7’ exhibited highest similarity factor of 56.1. Stability tests conducted over a three-month period under accelerated settings established that the optimized formulation is stable. GRAPHICAL ABSTRACT