Influence of the type of enteric coating suspension, coating layer and process conditions on dissolution profile and stability of coated pellets of diclofenac sodium

Abstract

In this work, diclofenac sodium pellets were produced through an extrusion/spheronization process and subsequently coated in a fluidized bed coater column with a Wurster insert. The aim of this work was to study the coating of pellets with two commercial aqueous enteric polymer suspensions, Advantia® Performance and Acryl-Eze® MP. The coating process was studied with a 23 experimental design. The variables were as follows: inlet air temperature, suspension flow rate and coating polymer. The response variables were as follows: the process efficiency, which generated results above 78.2%, and the agglomeration fraction, which generated results below 8%. The polymer coating type was the variable that influenced the response variables the most. The minimum masses gain needed to achieve enteric release were also determined: Acryl-Eze® MP: 9.7% and Advantia® Performance: 8.6%. The coated pellets were tested for drug content, dissolution and stability. Neither the drug content nor the release profiles were significantly affected by storage at 40°C and 75%. The suspensions were tested for rheology, contact angle and static wettability to investigate the characteristics of the polymer. © 2014 Elsevier B.V.