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Topic: How does the bulk density of a granulated drug sample relate to its bioavailability?

posed by  Last edited: 21 April 2014 At 3:57pm
How does the bulk density of a granulated drug sample relate to its bioavailability?
  • Avatar Fernando Muzzio Community Member 1 Post

    Re: How does the bulk density of a granulated drug sample relate to its bioavailability?

    There is no straight answer because it depends on the drug release mechanism of the finished drug.

    If the drug is being granulated ad then compressed as a non-disintegrating form, then, an increase of granule density will correlate to a decrease in porosity and therefore, slower drug release.

    However, in many cases a matrix-forming polymer would be included, either intra or extra granular. In such a case, you would find that the granule density/porosity has no impact on drug release.

  • Avatar Ronald Warrick Community Member 2 Posts

    Re: How does the bulk density of a granulated drug sample relate to its bioavailability?

    Last edited: 2 October 2014 at 1:23am
    In general, for a well formulated product, there will be no relationship. However, if for some reason, one were to see such a correlation in one's product, there might be an explanation. The explanation would depend on what was causing the difference in bulk density in the first place - i.e, is it the density of the individual granules, or the granule size distribution, or a difference in the dispersion of ingredients? For each of these cases, then, there are multiple possibilities as to why dissolution rate, and thus bioavailabilty, might be affected. Denser granules being less porous may retard dissolution, or if they produced a tablet at a lower compression force, might improve tablet disintegration and dissolution. Granule size distribution may affect the porosity of the finished table (if it is a tablet). Incomplete dispersion can cause dissolution problems by leaving hydrophobic material in the path of diffusion during disintegration or dissolution. So, it is not a simple problem. All one can say is there is more to it than bulk density alone.