Evaluation of controlled-release polar lipid microparticles.
The aim of the present study was to prepare controlled-release tablets of poorly-soluble drug, felodipine, and various erodable lipophilic excipients. Spray chilling was used to formulate the drug and the excipients into solid dispersion microparticles, which were then compressed. The microparticles were characterised by Fourier transform infrared spectroscopy, hot-stage microscopy, scanning electron microscopy, and image analysis. The amine and the carbonyl groups of felodipine formed hydrogen bonds with the carriers. The shape of the particles was spherical with the median particle diameter ranging from 25 to 35 microm. Surprisingly, the degree of crystallinity in felodipine and the ease of tablet disintegration played a more significant role on the felodipine dissolution rate than the matrix lipophilicity. Felodipine release rate was slowest from the least lipophilic tablets.
Department of Pharmacy, Pharmaceutical Technology Division, P.O. Box 56, FIN-00014 University of Helsinki, Helsinki, Finland. marja.savolainen@helsinki.fi
Marja
M
Savolainen
Cynthia
C
Khoo
Håkan
H
Glad
Carina
C
Dahlqvist
Anne Mari
AM
Juppo
D000959:Antihypertensive Agents / Q000008:administration & dosage* / Q000032:analysis; D002626:Chemistry, Pharmaceutical / Q000379:methods*; D002851:Chromatography, High Pressure Liquid; D003692:Delayed-Action Preparations; D005069:Evaluation Studies as Topic; D005079:Excipients / Q000145:classification; D015736:Felodipine / Q000008:administration & dosage* / Q000032:analysis; D008055:Lipids; D017550:Spectroscopy, Fourier Transform Infrared; D013607:Tablets
D000959:Antihypertensive Agents; D003692:Delayed-Action Preparations; D005079:Excipients; D008055:Lipids; D013607:Tablets; D015736:Felodipine