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Identifying and Mapping Surface Amorphous Domains

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Purpose

Undesirable amorphous material generation during formulation is implicated in a growing number of pharmaceutical problems. Due to the importance of interfacial properties in many drug delivery systems, it seems that surface amorphous material is particularly significant. Consequently, this study investigates a range of methods capable of detecting and mapping surface amorphous material.

Methods

A micron-sized localized surface domain of amorphous sorbitol is generated using a novel localized heating method. The domain is subsequently investigated using atomic force microscopy (AFM) imaging, nanomechanical measurements, and Raman microscopy 3-D profiling.

Results

AFM phase and height images reveal nanoscale-order variations within both crystalline and amorphous sorbitol domains. Nanomechanical measurements are able to quantitatively distinguish the amorphous and crystalline domains through local Young’s modulus measurements. Raman microscopy also distinguishes the amorphous and crystalline sorbitol through variations in peak width. This is shown to allow mapping of the 3-D distribution of the amorphous phase and is hence complementary to the more surface sensitive AFM measurements.

Conclusions

AFM and Raman microscopy map the distribution of amorphous material at the surface of a sorbitol crystal with submicron spatial resolution, demonstrating surface analysis methods for characterizing semicrystalline solids generated during pharmaceutical processing.

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References

  1. D. Giron M. Mutz S. Garnier (2004) ArticleTitleSolid state pharmaceutical compounds: impact of the ICH Q6 guideline on industrial development J. Therm. Anal. Calorim. 77 709–747

    Google Scholar 

  2. G. Brittain (2002) ArticleTitleEffects of mechanical processing on phase composition J. Pharm. Sci. 91 1573–1579

    Google Scholar 

  3. J. Pirttimäi E. Laine J. Ketolainen P. Paronen (1993) ArticleTitleEffect of grinding and compression on crystal structure of anhydrous caffeine Int. J. Pharm. 95 93–99

    Google Scholar 

  4. A. Bauer-Brandl (1996) ArticleTitlePolymorphic transitions of cimetidine during manufacture of solid dosage forms Int. J. Pharm. 140 195–206

    Google Scholar 

  5. D. Singhal W. Curatolo (2004) ArticleTitleDrug polymorphism and dosage form design: a practical perspective Adv. Drug Deliv. Rev. 56 335–347

    Google Scholar 

  6. M. Murtomaa V. Mellin P. Harjunen T. Lankinen E. Laine V.-P. Lehto (2004) ArticleTitleEffect of particle morphology on the triboelectrification in dry powder inhalers Int. J. Pharm. 282 107–114

    Google Scholar 

  7. G. Buckton P. Darcy D. Greenleaf P. Holbrook (1995) ArticleTitleThe use of isothermal microcalorimetry in spray-dried salbutamol sulphate Int. J. Pharm. 116 113–118

    Google Scholar 

  8. G. Buckton P. Darcy (1995) ArticleTitleThe influence of additives on the recrystallisation of amorphous spray dried lactose Int. J. Pharm. 121 81–87

    Google Scholar 

  9. G. Buckton (1997) ArticleTitleCharacterisation of small changes in the physical properties of powders of significance for dry powder inhaler formulations Adv. Drug Deliv. Rev. 26 17–27

    Google Scholar 

  10. V. Bérard E. Lesniewska C. Andrés D. Pertuy C. Laroche Y. Pourcelot (2002) ArticleTitleAffinity scale between a carrier and a drug inDPI studied by atomic force microscopy Int. J. Pharm. 247 127–137

    Google Scholar 

  11. R. C. Rowe P. J. Shesky P. J. Weller (2003) Handbook of Pharmaceutical Excipients Pharmaceutical Press London

    Google Scholar 

  12. R. A. Talja Y. H. Roos (2001) ArticleTitlePhase and state transition effects on dielectric, mechanical and themal properties of polyols Thermochim. Acta 380 109–121

    Google Scholar 

  13. J. X. Zhang A. J. Busby C. J. Roberts X. Y. Chen M. C. Davies S. J. B. Tendler S. M. Howdle (2002) ArticleTitlePreparation of a poly(methyl methacrylate)/ultrahigh molecular weight polyethylene blend using supercritical carbon dioxide and the identification of a three-phase structure: an atomic force microscopy study Macromolecules 35 8869–8877

    Google Scholar 

  14. R. Price P. M. Young (2004) ArticleTitleVisualization of the crystallisation of lactose from the amorphous state J. Pharm. Sci. 93 155–164

    Google Scholar 

  15. D. Mahlin J. Berggren G. Alderborn S. Engström (2004) ArticleTitleMoisture-induced crystallisation of spray-dried amorphous lactose particles studied by atomic force microscopy J. Pharm. Sci. 92 29–37

    Google Scholar 

  16. L. S. Taylor A. C. Williams P. York (1998) ArticleTitleParticle size dependant molecular rearrangements during the dehydration of trehalose dehydrate-in situ FT-Raman spectroscopy Pharm. Res. 15 1207–1214

    Google Scholar 

  17. J. X. Zhang C. J. Roberts K. M. Shakesheff M. C. Davies S. J. B. Tendler (2003) ArticleTitleMicro- and macrothermal analysis of a bioactive surface-engineered polymer formed by physical entrapment of poly(ethylene glycol) into poly(lactic acid) Macromolecules 36 1215–1221

    Google Scholar 

  18. G. Bar Y. Thomann R. Brandsch H. J. Cantow M. H. Whangbo (1997) ArticleTitleFactors affecting the height and phase images in tapping mode atomic force microscopy. Study of phase-separated polymer blends of poly(ethene-co-styrene) and poly(2,6-dimethyl-1,4-phenylene oxide) Langmuir 13 3807–3812

    Google Scholar 

  19. R. Levy M. Maaloum (2002) ArticleTitleMeasuring the spring constant of atomic force microscope cantilevers: thermal fluctuations and other methods Nanotechnology 13 33–37

    Google Scholar 

  20. M. Radmacher (1997) ArticleTitleMeasuring the elastic properties of biological samples with the AFM IEEE Eng. Med. Biol. Mag. 16 47–57

    Google Scholar 

  21. A. N. Round B. Yan S. Dang R. Estephan R. E. Stark J. D. Batteas (2000) ArticleTitleThe influence of water on the nanomechanical behavior of the plant biopolyester cutin as studied by AFM and solid-state NMR Biophys. J. 79 2761–2767

    Google Scholar 

  22. E. A-Hassan W. F. Heinz M. D. Antonik N. P. D’Costa S. Nageswaran C. A. Schoenenberger J. H. Hoh (1998) ArticleTitleRelative microelastic mapping of living cells by atomic force microscopy Biophys. J. 74 1564–1578

    Google Scholar 

  23. S. J. Ebbens J. P. S. Badyal (2001) ArticleTitleSurface enrichment of fluorochemical-doped polypropylene films Langmuir 17 4050–4055

    Google Scholar 

  24. J. P. Cleveland B. Anczykowski A. E. Schmid V. B. Elings (1998) ArticleTitleEnergy dissipation in tapping-mode atomic force microscopy Appl. Phys. Lett. 72 2613–2615

    Google Scholar 

  25. M. Heubeger G. Dietler L. Schalapbach (1994) ArticleTitleMapping the local Young’s modulus by analysis of the elastic deformations occurring in atomic force microscopy Nanotechnology 5 12–23

    Google Scholar 

  26. J. Domke M. Radmacher (1998) ArticleTitleMeasuring elastic properties of thin polymer films with the atomic force microscope Langmuir 14 3320–3325

    Google Scholar 

  27. S. E. Dilworth G. Buckton S. Gaisford R. Ramos (2004) ArticleTitleApproaches to determine the enthalpy of crystallisation, and amorphous content of lactose from isothermal calorimetric data Int. J. Pharm. 284 83–94

    Google Scholar 

  28. L. S. Taylor G. Zografi (1998) ArticleTitleThe quantitative analysis of crystallinity using FT-Raman spectroscopy Pharm. Res. 15 755–761

    Google Scholar 

Download references

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Correspondence to Stephen J. Ebbens.

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Ward, S., Perkins, M., Zhang, J. et al. Identifying and Mapping Surface Amorphous Domains. Pharm Res 22, 1195–1202 (2005). https://doi.org/10.1007/s11095-005-6027-4

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  • DOI: https://doi.org/10.1007/s11095-005-6027-4

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