Objectives: To evaluate the continuous feeding behavior of lubricated blends and assess
the use of BARDS as an at-line PAT tool enabling the monitoring of blends and tablets.
Methods: Blend-1 (microcrystalline cellulose 90%w/w + metoclopramide 10%w/w and
Blend 2 (microcrystalline cellulose 89.5%w/w + metoclopramide 10%w/w + magnesium
stearate 0.5%w/w) were prepared using a double cone blender and fed using a K-Tron
MT12 continuous feeder at 3 feed rates. Feeder performance was evaluated using a KSampler
Test System. Variability (%RSD) was determined from data collected at 30sec
intervals over 30mins. Blend compaction profiles following feeding were generated on a
Riva tablet press.
Broadband Acoustic Resonance Dissolution Spectroscopy (BARDS) recorded the steady
state resonance of the system for 30 s1. Changes in the pitch of the resonance of system
upon material addition was recorded for 800-1200 seconds.
Results: Reduced %RSD at 3 different set points was observed for Blend 2. More
variability was observed at lower set points for both blends. BARDS revealed different
acoustic profiles for Blend 1 and 2 due to the presence of lubricant. BARDS detected
differences in lubricated blends fed at different set points demonstrating increased
lubrication. Increased feed rate negatively effected tablet tensile strength indicating
increased lubrication for Blend 2. BARDS detected differences in tablets of same
composition but different lubricant distribution and tensile strength. BARDS distinguished
between tablets compressed at different forces and between tablets prepared from Blend
1 and 2 at similar compression forces.
Conclusions: A deeper understanding of the impact of processing parameters in the
feeding stage and inclusion of lubricant in fed blends on compression was obtained. The
potential of BARDS as novel at-line PAT tool in pharmaceutical processing to detect
differences in blends and the effect of processing parameters was demonstrated.
1. Fitzpatrick, D. et al. (2012). Analytical chemistry, 84(5), 2202-2210.