Preparation of glass solutions of three poorly water soluble drugs by spray drying, melt extrusion and ball milling - Spray Drying

Preparation of glass solutions of three poorly water soluble drugs by spray drying, melt extrusion and ball milling
Received 6 August 2006; revised 13 October 2006; accepted 6 November 2006. Available online 15 November 2006
James E. Pattersona, b, Michael B. Jamesb, Angus H. Forsterb, 1, Robert W. Lancasterb, 2, James M. Butlerb and Thomas Radesa
International Journal of Pharmaceutics
Volume 336, Issue 1, 4 May 2007
ScienceDirect
Copyright ? 2006 Elsevier B.V. All rights reserved.
aSchool of Pharmacy, University of Otago, Dunedin, New Zealand
bGlaxoSmithKline, Harlow, United Kingdom
Abstract
The aim of this study was to investigate the influence of the manufacturing process on the physicochemical properties of three poorly water soluble compounds (carbamazepine, dipyridamole, and indomethacin) when processed with a polymer (polyvinylpyrrolidone K30 (PVP)) at a 1:2 drug to polymer ratio. Melt extrusion, spray drying, and ball milling techniques were used to prepare glass solutions. Product homogeneity, dissolution, physical stability, and drug/polymer interactions were investigated. Particular attention was paid to solid phase analysis using XRPD, modulated temperature DSC, optical microscopy, and Raman microscopy and the importance of using a combination of techniques was demonstrated. The latter technique when applied to freshly ball milled samples exhibited the presence of drug and polymer rich areas, indicating that complete glass solution formation had not occurred. The three compounds produced products with differing physical stability with indomethacin proving the most physically stable. These differences in physical stability were attributed to hydrogen bonding of drug and polymer. The manufacturing technique did not influence physical stability, but it did affect dissolution. The dissolution of the spray-dried material was generally poor, compared to melt extruded and ball milled products. This was probably due to rapid dissolution of PVP from the small particles of the spray-dried products.
Keywords: Glass solutions; Spray drying; Milling; Melt extrusion; Indomethacin; Carbamazepine; Dipyridamole; Poly(vinylpyrrolidone)
Corresponding author. Tel.: +64 3 479 5410; fax: +64 3 479 7043.
1 Present address: PA Consulting Group, Cambridge, United Kingdom.
2 Present address: University College London, United Kingdom.
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