Purpose: Purpose of this study was to develop storage stable pellets coated with the aqueous ethylcellulose dispersion Aquacoat ECD.
Methods: The influence of accelerated curing/storage conditions on the release behavior of Aquacoat/HPMC-coated drug pellets were investigated as a function of various formulations (sealing, plasticizer content, and pore-former type/amount) and process parameters (process humidity, thermal curing, and organic processing).
Results: Conventionally cured Aquacoat/hydroxypropyl methylcellulose- coated pellets were storage stable at ambient conditions and 25 degrees C/60% relative humidity (RH) but showed a decreasing drug release at 40 degrees C/75% RH, which is a required test condition according to ICH guidelines.
Conclusion: Only organic processing of dried Aquacoat or unconventionally harsh curing conditions (60 degrees C/75% RH or 80 degrees C) improved the storage stability of Aquacoat-coated pellets at accelerated conditions.