Historiquement, la pilule est l'ancêtre du comprimé, terme aujourd'hui exclusivement réservé pour désigner une « pilule contraceptive ».
Les particules sont constituées d’une ou plusieurs substances actives, additionnées ou non d’excipients tels que : diluants, liants, désagrégeants, agents d’écoulement, lubrifiants, composés pouvant modifier le comportement de la préparation dans le tube digestif, colorants, arôme.
http://fr.wikipedia.org/wiki/Comprimé

A tablet is a pharmaceutical dosage form. It comprises a mixture of active substances and excipients, usually in powder form, pressed or compacted from a powder into a solid dose. The excipients can include diluents, binders or granulating agents, glidants (flow aids) and lubricants to ensure efficient tabletting; disintegrants to promote tablet break-up in the digestive tract; sweeteners or flavours to enhance taste; and pigments to make the tablets visually attractive. A polymer coating is often applied to make the tablet smoother and easier to swallow, to control the release rate of the active ingredient, to make it more resistant to the environment (extending its shelf life), or to enhance the tablet's appearance.
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Compressed tablets are defined as solid-unit dosage forms made by compaction of a formulation containing the drug and certain fillers or excipients selected to aid in the processing and properties of the drug product.
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Tablet formulations are designed and tested using a laboratory machine called a Tablet Compaction Simulator or Powder Compaction Simulator.
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Stages of Compaction / Events occurring during Compaction
a. Particle rearrangement / inter-particle slippage / transitional repacking b. Deformation at Points of Contact c. Fragmentation and Deformation d. Bonding e. Deformation of the solid body f. Decompression g. Ejection
http://en.wikipedia.org/wiki/Tablet_(pharmacy)


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Note added at 7 days (2012-10-15 20:10:40 GMT) Post-grading
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Some excerpts from Liz' link:

Silicification of MCC improves the functionality of MCC with such properties as enhanced density, low moisture content, flowability, lubricity, larger particle size, compactibility and compressibility.
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For using oxidized cellulose as a direct compression excipient Banker and Kumar grounded it and prepared tablets by mixing the ingredients by ratio of 20, 79 and 1% for oxidized cellulose, lactose NF (Fast-Flo), magnesium stearate respectively, each tablet weighed 500 ± 10 mg. The hardness, the disintegration times and water penetration rate were 5.17 kg, 30 sec and 10.49 mg/sec respectively [73].
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Also, Guo and Augsburger compared SMCC’s performance to that of other excipients commonly used in hard gelatin capsule direct-fill formulations such as anhydrous lactose (direct tableting grade), pregelatinized starch (PGS), and MCC. The study revealed that SMCC exhibited relatively higher compactibility under the low compression force of a donator capsule filling than either PGS or lactose.
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Also, tensile strength of compacts of SMCC is greater than that of the respective MCC [76] and it is most probably a consequence of intersurface interactions of silicon dioxide and MCC [77].
Tableting studies have suggested that SMCC has enhanced compactibility,
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Such higher compactibility and fast dissolution rates suggest that SMCC could be a suitable alternative excipient for direct- fill formulations for hard shell capsules [79].
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Cellulose ethers are widely used as important excipients for designing matrix tablets.
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Cellulose derivatives are often used to modify the release of drugs in tablet and capsule formulations and also as tablet binding, thickening and rheology control agents, for film formation, water retention,
improving adhesive strength, for suspending and emulsifying.
MCC is used as diluent and disintegrating agent for release oral solid dosage. HEC and HPC are used in hydrophilic matrix systems, while EC can be used in hydrophobic matrix system.
www.expresspolymlett.com/letolt.php?file=EPL-0000662&mi=cc

Conclusion: This articles supports my proprosal rather than any "matrix hardening".