Preparation And Evaluation Of Inclusion Complexes Of Felodipine,

Abstract

Studies were carried out on the complexation of felodipine with β-cyclodextrin(β-
CD) and hydroxypropyl β-cyclodextrin(HP β-CD) with the objective of developing a new oral
dosage form with enhanced dissolution rate and bioavailability. Equimolar drug-cyclodextrin
binary systems were prepared according to three different techniques (physical mixing, kneading
and solvent evaporation) and were characterized by infrared, FTIR studies and comparative invitro
studies. The drug solubility improvement obtained by the different binary systems varied
from a minimum of 2.5 times up to a maximum of 120 times, depending on both the cyclodextrin
type and the method of preparation. Phase solubility studies indicated formation of 1:1 M
complex for HP β-CD. Apparent stability constant (Kc) was found to be 582.78 M-1 for HP β-CD
complexes. Solid complexes of felodipine-HP β-CD at 1:1 M prepared by kneading method
exhibited the highest dissolution rate and dissolution efficiency values than the pure drug and
other complexes. It can be reasonably expected that the obtained drug dissolution rate
improvement will result in an increase in its bioavailability, with the possibility of reducing dose
and side effect.
Keywords: Felodipine, β-cyclodextrin, HP β-cyclodextrin, Physical mixture, Kneading method,