A serious problems have been encountered in transferring a new antidepressant Placebo xx® from a production plant in Puerto Rican plant to the Rocklea facility in Brisbane, Australia. In the development batch, granulation was very poor. Tablets formed had low crush strength and high friability. This formulation has previously given no problems in Puerto Rico and none were anticipated in Australia, so production schedules have been pushed back. This is a serious issue as demand for Placebo xx® in Australia is booming. It is suspected that the change in behaviour of formulation is due to sourcing of lactose powder which comprises 94.2% w/w of Placebo xx®. The lactose used at Rocklea is from the Delicious Dairy Co. in Hamilton, New Zealand, while Puerto Rico uses lactose from the US supplier. We have already established there is no difference in chemical properties between the two sources of lactose.
Background information on Placebo xx® manufacture:
• Dry powder blending
• Wet granulation
• Fluid bed drying
• Milling (to crush lumps formed during granulation)
• Conveying to tablet press feed hoppers
Furthermore, a significant cause of the failure of direct compression formulations is blend segregation leading to content uniformity problems, due to changes in the performance patterns of drugs and excipients. The reasons are currently poorly understood but tribo-electric phenomena are believed to be a significant contributor.
An improved understanding of tribo-electric properties and how they relate to individual powders would contribute to the understanding of these issues, thereby enabling the specification of particles with desired properties for optimum manufacture. However, currently the company lacks the capability (knowledge, equipment, instruments, and experience to interpret the results) to carry out robust, reproducible tribo-electric characterisation of pharmaceutical powders.
Write a detailed report to address the following points;
a) Identify any differences in physical properties of the two types of lactose that could explain their different granulation and tableting behaviour.
b) Recommend a standard set of characterisation tests to be performed on all newly sourced formulation ingredients in the future.
c) Explain how the increased understanding of particle properties will contribute to problem solving. In your answer you should consider how optimised manufacturing systems contribute to fewer batch failures and cost savings.
d) Describe the theory behind tribo-electrification phenomena explaining how the mechanisms of charge transfer play role in particle electrification to address the lack of understanding the company has on this subject.
e) Explain how segregation may arise from triboelectrification of particulate materials and recommend measures to implement to minimise segregation.
f) Describe and evaluate different devices available for electrostatic characterisation that the company could employ to tackle the issues arising from triboelectrification of powder materials.
g) Make recommendations to reduce and control particle electrification during particulate processing.
Follow the guidelines for the report writing and referencing provided in the laboratory manual. Word limit of 3,000 words applies.