Pharmaceutical tablet compaction : product and process design

This thesis explores how tablet performance is affected by microstructure, and how microstructure can be controlled by selection of excipients and compaction parameters. A systematic strategy for formulation and process design of pharmaceutical tablets is proposed. A modified nanoindenter method was used to test the mechanical behavior of diametrally compressed excipient granules. X ray micro computed tomography and Terahertz pulsed spectroscopy (TPS) and imaging (TPI) were used to analyze the microstructure of the tablet core and detect internal defects. Granule failure mechanisms are found to be consistent with tablet microstructure. MCC granules deform plastically when tested and X ray images show individual granules undergoing increasing deformation in tablets as higher compaction forces are used. A highly interconnected pore-structure limited tablet hardness and led to bursting behavior during dissolution. No effect of compaction force or speed was observed in dissolution profiles. Lactose granules fracture at strains less than 5%, forming monolithic structures with no evidence of initial granule shape or size. Pore size decreases as compaction force is increased for DCL 11 tablets. A decreasing pore size corresponds to increasing THz refractive index, tablet hardness and dissolution time. DCL 11 and DCL 14 tablets compacted under the same conditions have the same pore size distributions and hardness, although DCL 14 granules are weaker than DCL 11, and DCL 14 tablets dissolve up to four times slower than DCL 11 tablets. No difference was observed between the THz spectra of tablets made from the two grades of lactose.

Department dc:contributor.department

Massachusetts Institute of Technology. Dept. of Chemical Engineering.

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2009

Author dc:creator

• Pore, Mridula

Advisor dc:contributor.advisor

• Charles L. Cooney.

• Chemical Engineering.

Statement dc:rights

• M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission.

Licence dc:rights.uri

• http://dspace.mit.edu/handle/1721.1/7582

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/1721.1/51623

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/51623