Molecular Complex of Amlodipine Besylate: Pharmaceutical Characterization and Stability Improvisation

Abstract

The study explains to increase the stability of a drug which is hygroscopic in nature (amlodipine besylate), by
the molecular complex technique. The stability enhancement achieved using the cocrystallization method by
the formation of a molecular complex. Saccharin as a coformer is formed by molecular complex. The selection
of coformer was done based on the Hansen parameter where theoretical value was obtained which gave some
coformer values and practically molecular complex study was carried out by the solubility method. No any
interaction between amlodipine besylate and saccharin was confirmed by Fourier transform infrared (FTIR)
and differential scanning calorimetry (DSC) studies. The stability-enhancing property of cocrystals was carried
out by short-term accelerated stability studies. To perform stability analysis, few methods of cocrystallization
were carried out. These cocrystals were evaluated by FTIR, DSC, and powder X-ray diffraction studies. It is
concluded that the molecular complex of amlodipine besylate with sodium saccharin shows significant stability
and highlights the use of cocrystallization in stability enhancement. The miscibility of drug and coformers as
predicated by Hansen solubility parameter, can indicate cocrystal preparation. The resultant δ values of drug and
coformers are compared and their solid state miscibility is expressed. The possibility of cocrystal formulation by
krevelens is Δδ < 5 MP and Greenhalgh Δδ < 7 MP