Preparation and Characterization of Lercanidipine Hydrochloride Inclusion Complex with β-Cyclodextrin and effect of Complexation on Solubility and Dissolution

Lercanidipine Hydrochloride (LER) is widely used antihypertensive drug belonging to BCS Class II and showing pH dependent solubility. The bioavailability of LER is limited because of its poor water solubility. Inclusion complexes of LER were prepared with β-Cyclodextrin (βCD) using kneading and freeze drying techniques in different molar ratios to enhance solubility of LER and improve dissolution characteristic of the same. The phase solubility study was performed to study interaction between βCD and LER in solution. Phase solubility graph showed a linear diagram classified as AL type. From the slope of phase solubility diagram, stability constant K was calculated and was found to be 428.28 M^-1 suggesting strong interaction between guest and host molecule. Water solubility and dissolution was significantly increased when inclusion complex was prepared by freeze drying technique in 1:1.5 Molar ratio. Further formation of inclusion complex was confirmed by Fourier transformation-infrared (FT-IR), powder X-ray diffractometry (PXRD) and ¹H Nuclear Magnetic Resonance (NMR). Solid state characterization suggested strong interaction of LER in βCD forming inclusion complex. From the result of XRD, it was confirmed that the decrease in crystal structure of LER takes place upon formation of inclusion complex. Freeze dried inclusion complex of LER with βCD in 1:1.5 molar ratio showed 5.4 fold increase in solubility of LER along with 80 % release in 60 minutes. The study concludes that Cyclodextrin complexation can influence solubility and dissolution of LER positively and thus can be used to design novel formulation of LER with improved dissolution and bioavailability.