Relationship of hardness to porosity tablets

relationship of hardness to porosity tablets

Thus, there is a correlation between the hardness data and the porosity data. The difference in porosity of prepared specimens and tablets are explained by the. We also found a strong correlation between TPI results and tablet bulk density, and how these hertz pulsed imaging (TPI); tablet hardness testing; density distribution; finite element analysis porosity and hence density. particle density, porosity and friability. The results showed that carried out to impart cohesiveness to the tablet formula- tion and to improve on.

By reducing the specific surface area, you can prevent or control inter-particulate interaction and the resultant cohesion to improve flow. Surface area by gas adsorption is the preferred measurement technique. When coupled with mercury porosimetry, this provides two complimentary techniques for pore size, pore size distribution, and surface area.

It is capable of increasing the speed and efficiency of routine quality control analyses, yet has the accuracy, resolution, and data reduction capability to meet most research requirements. Each analysis station is upgradeable from mesopore to micropore. All analysis stations can be configured for krypton analysis of low surface area materials.

The 3Flex is capable of analyzing three samples in parallel so that three complete isotherms are collected in the time required for one analysis. Each of the analysis ports is capable of achieving very low absolute pressures as a direct result of our innovative design.

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Since smaller pore sizes are measured at lower relative pressures, micropore data are more accurately measured. Several mechanisms are at work within this process that have material effect on the final dosage form, including content uniformity. These include material flow properties, compactibility, compressibility, roll pressure, roll speed, and hopper feeding dynamics. One of the key elements in roller compaction is roll pressure.

Several studies show that this parameter has a direct effect on tablet dissolution performance. This solid fraction information can provide the necessary insight to optimize granules and establish controlled roll pressures.

Micromeritics offers a Density Solution bundle that accurately and non-destructively measures true, apparent, and envelope densities. These tests can be done in the laboratory or performed at-line.

The procedure is simple, accurate, and highly repeatable. This technique is non-destructive as it uses the gas displacement method to measure volume. If the solvent is only present in low concentration, the stiff slurry can be pressed through a sieve of appropriate mesh size and the resultant granules allowed to fall into a cooling medium. When the mixture is of low viscosity or is a solution, it can be sprayed through nozzles or spray cannules and introduced into a cooling medium im the form of fine droplets.

In both cases, after separation from the cooling medium, flowable granulates are obtained which can be pressed in the usual manner in tablet presses to give tablets of the desired shape and size.

relationship of hardness to porosity tablets

Of course, care is to be taken that the pressing process is carried out at a temperature below the melting point of the eutectic mixtures of the tablet components with the solvent. The solvent can be removed from the finished tablets, for example by lyophilization or also by air drying when the tablets obtained are sufficiently form-stable even after the solvent has melted.

The rate of dissolution of tablets obtained according to this process can be controlled within wide limits, especially by the amount of solvent added and by the size and number of the hollow spaces left behind after the evaporation thereof. Naturally, the hardness of the tablets is the greater, the smaller is the amount of solvent added and, therefore, the smaller the number and size of the hollow spaces. Furthermore, the hardness is also considerably influenced by the pressure used for the pressing, the tablets being harder, the more strongly the components are compressed and compacted together.

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Furthermore, it is possible to select solvents in which at least one of the substances to be tabletted is soluble so that this substance is dissolved either by the localized heating resulting upon pressing or by melting after the pressing process and subsequently, upon decompressing or upon drying, the mixture sticks together and thus the hardness of the resulting tablets is increased.

On the other hand, of course, especially porous tablets can be obtained by carrying out the production of the tablets under very low pressures and removing the solvent by lyophilization at a low temperature, as well as by using comparatively large amounts of solvents, which increases the number and size of the hollow spaces.

Surprisingly, by means of this process, it is also possible to tablet salts which are completely soluble in the solvent and, in particular, these mixtures can also be satisfactorily tabletted without the addition of lubricants without sticking to the press, this process thereby differing especially advantageously from that used for the production of "molded tablets".

relationship of hardness to porosity tablets

As solvents, there can, in principle, be used all those which, at ambient temperature, do not damage the components of the tablets, which freeze upon cooling in technically useable ranges, i.

Because of their universal applicability and cheapness, it is especially preferred to use water, cyclohexane, benzene or tert. The tablets produced by the process according to the present invention disintegrate within a few seconds into small particles which can also be dissolved in less than one minute.

relationship of hardness to porosity tablets

The rate of dissolution of these tablets is, therefore, superior to that of the tablets produced by the process according to U. The following Examples are given for the purpose of illustrating the present invention: The tablets obtained are dried at ambient temperature over a drying agent.

The tablets obtained are air dried at ambient temperature under a flue. The frozen, flowable granulate obtained is tabletted as in Example 1. The tablets obtained are dried by lyophilization.

relationship of hardness to porosity tablets

The granulate can be pressed without any melting effect or sticking taking place. The tablets obtained are dried in a desiccator over a drying agent or by lyophilization. The tablets obtained are dried at ambient temperature under waterpump vacuum.

The tablets obtained are dried under a vacuum of about 60 mm Hg. It will be appreciated that the specification and examples are illustrative but not limitative of the present invention and that other embodiments within the spirit and scope of the invention will suggest themselves to those skilled in the art. Claims 10 What we claim is: The process according to claim 1, wherein the solvent used comprises at least one of water, cyclohexane, benzene and tert.

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The process according to claim 2, wherein the solvent includes a lower alcohol.