Pharmaceutical Characterisation The     physical     characteristics     of     pharmaceuticals     profoundly influence   the   properties   and   effectiveness   of   the   final   dosage form,   be   it   administered   via   tablet,   granule   /   capsule   or   inhalation routes.   Furthermore,   knowledge   of   physical   characteristics   often contributes   to   the   critical   understanding   of   all   components,   such as   API,   excipients,   powder   blends   and   ribbons   as   well   as   the   final form.   They   are   also   applicable   to   all   stages   of   pharmaceutical processes:    from    formulation    through    manufacturing    to    quality control, stability trials and trouble-shooting atypical behaviour. Physical   characteristics   commonly   include   specific   surface   area (SSA),    pore    size    and    volume    distributions    and    density,    which together   provide   a   complete   understanding   of   overall   porosity.   In turn,   porosity   has   direct   effects   on   many   aspects   of   performance, for   example   dissolution   and   disintegration   rates,   strength   and hardness   and   long   term   stability   of   solid   dosage   forms.   They   also influence   formulation   and   effect   stability   of   solid   components   in many emulsion, paste and topical forms.

Key Applications Characterisation of API and excipient materials Characterisation of powder blends Dissolution rate study Disintegration study Investigation of batch failures and inter-batch variability Influence of stability trials on porosity Determination of long-term stability and shelf life Investigation and establishment of tabletting conditions Identification of counterfeit batches Significant to approval processes All analyses undertaken to ISO 17025 standards

Porosity   in   pharmaceutical   materials   can   be   present   in   various locations:   within   tablet   cores   and   granules,   coatings,   and   within the   particles   of   a   pre-cursor   powder   blend   and   also   the   void spaces   between   powder   particles.   The   latter   dictates   the   porous characteristics   of   tableted   forms.   SSA   measurement   is   routinely and   usefully   applied   to   the   characterisation   of   powder   samples but    the    pore    sizes    present    commonly    fall    within    the    range measured   by   the   mercury   porosimetry   technique.   This   provides   a complete   picture   of   pore   size,   pore   volume,   volume   porosity   and density.    It    can    also    provide    insight    to    pore    geometry.    These porosity    characteristics    then    dictate    performance    behaviours, may   be   indicative   of   atypical   performance,   and   often   change during the aging processes applied during stability trials.

Key Analytical Techniques Mercury Porosimetry Pore volume Distribution Pore Size Distribution Pore Area Distribution Absolute Porosity Bulk and Skeletal Density Pore Geometry Permeability Measurement Applicable to all solid forms Gas Adsorption BET Specific Surface Area by Nitrogen BET Specific Surface Area by Krypton (low SSA) Micro-pore / Meso-pore characterisation Pore volume Distribution Pore Size Distribution Pore Area Distribution

At   MCA   Services   we   offer   a   suite   of   analytical   techniques   for   the complete    characterisation    of    pharmaceutical    samples.    This    is combined   with   the   experience   and   expertise   to   actively   assist with    the    interpretation    of    results    directly    relating    these    to performance   characteristics   of   the   material.   We   have   many   years of     experience     partnering     with     the     pharmaceutical     sector, considering   a   wide   variety   of   dosage   forms   and   applications,   from formulation   to   stability   trials   and   identification   of   the   influence   of porosity to materials and batches having atypical behaviour.