Continuous manufacturing is a novel concept to produce high quality drug products. The manufacture of solid dosage forms starts with the feeding of materials, which is consider a critical step because it could have a high influence on the quality of the final product. Therefore, this unit operation is done by the so-called loss-in-weight feeders developed by various equipment manufacturers to ensure accurate feed rates that allows obtaining products in compliance with the specifications. Nonetheless, as the feed hopper of a feeder is of limited capacity, it must be refilled on regular basis to maintain continuous manufacturing. During refilling, dosing must be done in volumetric mode which can have an impact on dosing accuracy.

The present work studies the impact of the refill and different factors such as the feed rate, the refill system and the filling level at which the refill starts on the accuracy of the dose. Four performance indicators were used to evaluate this impact: the refilling time, the time out of the limits, the maximum or minimum feed rate during the refilling and the total deviation from the set point.

The refiller type and the filling level at which the refill starts play an important role and should be selected considering to the material's characteristics to be fed. As a general rule, a faster and shorter refill is always preferable, however, depending on the refiller type and the material, a positive or negative deviation from the feeding dose can be observed.

• New Technologies Innovation Center, Glatt GmbH, Werner Glatt-Straße 1, 79589 Binzen, Germany
• Institute for Pharmaceutical Technology & Biopharmaceutics, Heinrich Heine University, Universitätsstr. 1, 40225 Düsseldorf, Germany

• Oral Solid Dosage

1. Accuracy
2. Loss-in-weight feeder
3. oral solid dose
4. Refilling