Material powder compact

The method to be described determines the pore size distribution in a porous material or compacted powder surface areas may be inferred from the results. 

The success of compression agglomeration depends on the effective utilization and transmission ofthe applied external force and on the ability of the material to form and maintain interparticle bonds during pressure compaction (or consolidation) and decompression. Both these aspects are controlled in turn by the geometiy of the confined space, the nature of the apphed loads and the physical properties of the particulate material and of the confining walls. (See the section on Powder Mechanics and Powder Compaction.)... 

It should be observed that every element except the powder system in the recovery system is chosen for favorable shock properties which can be confidently simulated numerically. The precise sample assembly procedures assure that the conditions calculated in the numerical simulations are actually achieved in the experiments. The influence of various powder compacts in influencing the shock pressure and mean-bulk temperature must be determined in computer experiments in which various material descriptions are used. Fortunately, the large porosity (densities from 35% to 75% of solid density) leads to a great simplification in that the various porous samples respond in the same manner due to the radial loading introduced from the porous inclusion in the copper capsule. 

To demonstrate the ability to evaluate intersample variations, an over-the-counter (OTC) pain relief medication from two different manufacturers was compared. The samples contain three APIs each acetaminophen, aspirin and caffeine. Pure acetaminophen, aspirin and caffeine samples are obtained in either tablet form or powder compact and included within the same FOV as the tablets to provide simultaneous reference materials for the tablet samples. The tablets and pure components were arranged as shown in Plate 8.1a. Measurements on all samples were collected simultaneously. Tablet A samples from one manufacturer have a reported label concentration of 37%, 37%, and 10%, for the three API components, respectively. Tablet B samples from the second manufacturer contain the same three APIs, at label concentrations of 39%, 39%, and 10 %, respectively. In addition to these samples, tablet C samples are included in the array of tablets. These samples contain only acetaminophen as the API with a reported label concentration of 79%, and are made by the manufacturer who produces tablet A. The remaining mass of all three tablet types represents the excipient (binder, disintegrant, and lubricant) materials. 

The concentrations of the active ingredients as reported from the manufacturer s label are 37% acetaminophen, 37% aspirin, and 10 % caffeine. The remainder of the tablet mass represents the excipient (binder, disintegrant, and lubricant) materials. Pure acetaminophen, aspirin and caffeine samples are obtained in either tablet form or powder compact and used to obtain reference specua of pure components. 

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). 

Bolhius GK, Chowhan ZT. Materials for direct compaction. In Alderbom G, Nystrom C, eds. Pharmaceutical Powder Compaction Technology. New York Marcel Dekker, Inc., 1996 419-500. 

The systems may be similar powder compacts of the same powder material but, differing particle sizes, or they may be model systems such as those illustrated in Figs. 16.6 and 16.9 but with all corresponding length dimensions scaled similarly. 

To demonstrate the ability to evaluate inter-sample variations, tablet groups from two different manufacturers in an over-the-counter (OTC) pain relief medication were compared. Pure acetaminophen, aspirin, and caffeine samples are obtained in either tablet form or powder compact and included within the same FOV as the tablets to provide simultaneous reference materials for the tablet samples. The tablets and pure components were arranged as shown in Plate la. This FOV contains 20 tablets and the... 

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