title: Evaluation of polar lipid-hydrophilic polymer microparticles.
abstract: The aim of the present study was to prepare controlled-release tablets of poorly-soluble drug, felodipine. Spray chilling was used to formulate the drug, the polar lipids and the hydrophilic polymers into solid dispersion microparticles, which were then compressed. The microparticles were characterised by Fourier transform infrared and Raman spectroscopies, X-ray powder diffraction, hot-stage microscopy, scanning electron microscopy, and image analysis. The crystallinity of felodipine had decreased in all the samples, and the amount of crystalline felodipine varied depending on the composition of the solid dispersion. The particles were spherical with the median particle diameter ranging from 20 to 35 microm. The addition of hydrophilic polymer into the matrix widened the particle size distribution and increased the amount of agglomerates. Most promising dissolution patterns were obtained from tablets containing glycerides; e.g. from Precirol ATO 5/Pluronic F127 tablets the release was of zero order.
authors.affiliation: Department of Pharmacy, Pharmaceutical Technology Division, University of Helsinki, P.O. Box 56, FIN-00014, Finland. marja.savolainen@helsinki.fi
authors.forename: Marja
authors.initials: M
authors.lastname: Savolainen
authors.forename: Jenny
authors.initials: J
authors.lastname: Herder
authors.forename: Cynthia
authors.initials: C
authors.lastname: Khoo
authors.forename: Karin
authors.initials: K
authors.lastname: Lövqvist
authors.forename: Carina
authors.initials: C
authors.lastname: Dahlqvist
authors.forename: Håkan
authors.initials: H
authors.lastname: Glad
authors.forename: Anne Mari
authors.initials: AM
authors.lastname: Juppo
mesh_terms: D002626:Chemistry, Pharmaceutical; D003460:Crystallization; D003692:Delayed-Action Preparations / Q000737:chemistry*; D004339:Drug Compounding; D005079:Excipients / Q000737:chemistry*; D015736:Felodipine / Q000737:chemistry*; D008853:Microscopy / Q000379:methods; D010316:Particle Size; D012995:Solubility; D017550:Spectroscopy, Fourier Transform Infrared; D013059:Spectrum Analysis, Raman; D013607:Tablets / Q000032:analysis; D013997:Time Factors; D014961:X-Ray Diffraction
chemical_list: D003692:Delayed-Action Preparations; D005079:Excipients; D013607:Tablets; D015736:Felodipine