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Analytical techniques for quantification of amorphous/crystalline phases in pharmaceutical solids

Authors

  • Birju Shah,

    1. Department of Pharmaceutical Technology (Formulations), National Institute of Pharmaceutical Education and Research (NIPER), Sector-67, Phase-X, S.A.S. Nagar, Punjab 160 062, India
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  • Vasu Kumar Kakumanu,

    1. Department of Pharmaceutical Technology (Formulations), National Institute of Pharmaceutical Education and Research (NIPER), Sector-67, Phase-X, S.A.S. Nagar, Punjab 160 062, India
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  • Arvind K. Bansal

    Corresponding author
    1. Department of Pharmaceutical Technology (Formulations), National Institute of Pharmaceutical Education and Research (NIPER), Sector-67, Phase-X, S.A.S. Nagar, Punjab 160 062, India
    • Department of Pharmaceutical Technology (Formulations), National Institute of Pharmaceutical Education and Research (NIPER), Sector-67, Phase-X, S.A.S. Nagar, Punjab 160 062, India. Telephone: 91-0-172 2214682-87; Fax: 91-0-172 2214692
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Abstract

The existence of different solid-state forms such as polymorphs, solvates, hydrates, and amorphous form in pharmaceutical drug substances and excipients, along with their downstream consequences in drug products and biological systems, is well documented. Out of these solid states, amorphous systems have attracted considerable attention of formulation scientists for their specific advantages, and their presence, either by accident or design is known to incorporate distinct properties in the drug product. Identification of different solid-state forms is crucial to anticipate changes in the performance of the material upon storage and/or handling. Quantitative analysis of physical state is imperative from the viewpoint of both the manufacturing and the regulatory control aimed at assuring safety and efficacy of drug products. Numerous analytical techniques have been reported for the quantification of amorphous/crystalline phase, and implicit in all quantitative options are issues of accuracy, precision, and suitability. These quantitative techniques mainly vary in the properties evaluated, thus yielding divergent values of crystallinity for a given sample. The present review provides a compilation of the theoretical and practical aspects of existing techniques, thereby facilitating the selection of an appropriate technique to accomplish various objectives of quantification of amorphous systems. © 2006 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 95: 1641–1665, 2006

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