Compaction profile

Fig. 13 Compaction profile of five specially crystallized lots of ibuprofen. See Table 12 for description.

The use of compaction simulators was first reported in 1976. Since then, a variety of simulators have been developed. Hydraulic simulators, as well as mechanical simulators, are available to characterize raw materials, drug substances, and formulations, as well as to predict material behavior on scale-up. The appeal of simulators is due to the fact that they purport to provide the same compaction profile as experienced on a tablet press while using only gram or even milligram quantities of powders. Compaction simulators can achieve high speeds, as would be experienced on a production tablet press, and can be instrumented to measure a variety of parameters, including upper and lower punch force, upper and lower punch displacement, ejection force, radial die wall force, take-off force, etc. Summaries on the uses of simulators and tablet press instrumentation can be found in (19,20). 

Tablet hardness, friability, disintegration time and dissolution at 30minutes were the response variables that were measured. Tablets manufactured at 10 and 12kN were compared, as well as their compaction profiles. Table 4 shows the results from the fractional factorial DOE and Figure 19 shows the compaction profiles from the 20 batches.

Two additional experimental designs were carried out to optimize the formulation and granulation process (water addition time, granulating time, and addition of binder—dry versus in-solution— binder level, disintegrant level, and lubricant level). There was a trend toward improved compaction profiles and reduced friability with increased granulation time. It was also observed that the lubricant and disintegrant levels affected the friability of the tablets. The effect of the lubricant level on tablet friability is shown in Figure 20. The final formulation and process are summarized in Table 5. 

Figure 21 compares the compaction profiles from the 1 kg scale (at target conditions), 40 kg scale (plus and minus conditions) and 280 kg scale (at target conditions) batches. 

Through the use of DOE, a robust formulation and process were developed, resulting in tablets that could be produced at production scale. The compaction profile shifted slightly on scale-up to production, but tablet... 

Figure 19 Compaction profiles from the 2 experimental design.

Compaction profiles, which are plots of radial (die wall) pressure vs. axial (compaction) pressure to determine compression and decompression behavior... 

Ruegger, C. D. (1996), An investigation of the effect of compaction profiles on the tableting properties of pharmaceutical substances, Ph.D. thesis, Rutgers University, Newark, NJ. 

When the average tablet hardness is plotted against the average compression peak force, we get the so-called compactibility profile that allows us to compare different formulations or different processing speeds. Referring to Fig. 8, which formulation is better Well, formulation No. 2 makes harder tablets for the same compression force, and this would mean less wear and tear on the production press is required to achieve desired hardness. On the other hand, if the hardness tolerance limits are exceptionally narrow, the steeper slope of formulation No. 2 may be a detriment. 

FIGURE 30 Compaction profiles for tablets of different formulations evaluated using a compaction simulator Source Adapted from Ref. S3. 

FIGURE 34 Compactability profiles for various excipients at a range of tablering speeds. Source Adapted from Ref. 52. 

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Figure 1 Compaction profiles of microcrystalline cellulose powder and spheres. (From Ref. 17.)...

Figure 23 The effect of excipients on the compaction profile of spheres. Compaction profiles of spheres containing 10% theophylline with either MCC, MCC-DCP, or MCC-lactose in a 22.5 67.5 ratio using the Leunberger model. (From Ref. 17.)...

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