Preparation of Inclusion Complexes of Amlodipine Base and its Besylate and Maleate Salts with Hydroxy Propyl b -cyclodextrin -A study on Stereospecific Dissolution

Abstract

The objective of this work was preparation of inclusion complexes of amlodipine base and its besylate and maleate salts with hydroxy propyl ß-cyclodextrin to improve the dissolution and to investigate the stereospecific dissolution of amlodipine enantiomers. Different techniques like physicl mixing, kneading and solvent evaporation were tried to prepare the inclusion complexes of amlodipine base and its besylate and maleate salts with hydroxy propyl β-cyclodextrin (HPBC). Dissolution of prepared inclusion complexes was performed using USP type II apparatus in 0.1 N HCl at 75 rpm with temperature being maintained at 37±0.5 o C. Chromatographic separation of amlodipine enantiomers was performed on a Shimadzu HPLC System (Japan) equipped with UV-Visible detector using Chiral AGP column (100 x 4.6 mm I.D., 5µ particle size). Improvement in the dissolution was found with racemic amlodipine base where as no improvement was found with amlodipine besylate and maleate salts (p>0.05). This indicates the formation of inclusion complexes with only racemic amlodipine base (p< 0.05) which was also supported by their FTIR and DSC spectra. In case of physical mixing no inclusion complexes were formed even with enantiomers of amlodipine base (p>0.05). Stereospecific dissolution was observed with pure enantiomers of amlodipine base when its inclusion complexes were prepared by solvent evaporation method with l:1 & 1:2 molar ratios but not with 1:3 molar ratio.

Design and Evaluation of Orally Dispersible Tablets Containing Amlodipine Inclusion Complexes in Hydroxypropyl-β-cyclodextrin and Methyl-β-cyclodextrin

“…Amlodipine is a blocker of calcium channels from the group of dihydropyridine compounds, commonly used in the treatment of hypertension and angina pectoris [ 7 , 8 , 9 ]. Two forms of amlodipine are reported: S-enantiomer, which is more active, and R-enantiomer [ 10 , 11 ].…”

Novel chewable tablet-in-tablet dosage form of Orlistat and Venlafaxine hydrochloride: development and evaluation

“…Finally, the dry residue obtained was kept in a desiccator for 24h to remove the moisture. After drying completely, the dry mass was ground in a mortar and passed through sieve #60, labeled and stored in a desiccator until further use (Somagoni et al, 2011).…”