Amorphous solid dispersions

Ambike, A. A., K. R. Mahadik, and A. Paradkar. 2005. Spray-dried amorphous solid dispersions of simvastatin, a lowTg drucjn vitro andin vivoevaluationsPharm ReS2 990-998. 

Engers, D., Teng, J., Jimenez-Novoa, J., Gent, P., Hossack, S., Campbell, C., Thomson, J. et al. A Solid-state approach to enable early development compounds Selection and animal bioavailability studies of an itraconazole amorphous solid dispersion. J. Pharm. Sci. 2010, 99(9), 3901-3922. 

Qian, R, Wang, J., Hartley, R., Tao, J., Haddadin, R., Mathias, N., Hussain, M. Solution behavior of PVP-VA and HPMC-AS-based amorphous solid dispersions and their bioavailability implications. Pharm. Res. 2012, 29(10), 2766-2776. 

FIGURE 49.1 Types of solid dispersions (a) crystalline solid dispersion, (b) amorphous solid dispersion, and (c) amorphous solid solution. 

Compared to conventional CR formulation technologies, hot-melt extrusion (HME) offers several potential technical and business advantages. HME can be used to simultaneously generate an amorphous solid dispersion (ASD) and CR/ASD behavior, providing unique release profiles for low solubility molecules. It is also a convenient trend that a number of polymers used to generate... 

Konno, H. Handa, T. Alonzo, D.E. Taylor, L.S. Effect of polymer type on the dissolution profile of amorphous solid dispersions containing felodipine. Eur. J. Pharm. Biopharm. 2008, 70(2), 493-499. 

B. Van Eerdenbrugh, L.S. Taylor, An ab initio polymer selection methodology to prevent crystallization in amorphous solid dispersions by application of crystal engineering principles, CrystEng-Comm 13 (20) (2011) 6171-6178. 

Indomethacin (l-(p-chlorobenzoyl)-5-methoxy-2-methyIindole-3-acetic acid, IMC), can exist in several crystalline forms (e.g., a-, y-, and 8-polymorphs and others) [34, 62], Due to the poor water solubility of the most stable y-foim [63], IMC has been a popular choice as a model compound to explore the benefits of amorphous solid dispersions for enhancing solubility [64], thereby improving dissolution rates and oral bioavailability [65]. 

Baird JA, Taylor LS (2012) Evaluation of amorphous solid dispersion properties using thermal analysis techniques. Adv Dmg Deliv Rev 64(5) 396 21. doi 10.1016/j.addr.2011.07.009 Becker CR, Currano LJ, Churaman WA, Stoldt CR (2010) Thermal analysis of the exothermic reaction between galvanic porous silicon and sodium perchlorate. ACS Appl Mater Interfaces 2( 11 ) 2998-3003. doi 10.1021 /am100975u... 

Theoretical Considerations in Developing Amorphous Solid Dispersions... 

Calculation of solubility parameters (5) for a drug and a polymer have been used as a method for predicting miscibility in amorphous solid dispersions (Hancock et al. 1997), using, for example, the Hildebrand solubility parameter (Greenhalgh et al. 1999), which was calculated from the cohesive energy density (CED) by ... 

---