Formulation & evaluation of cyclodextrin complexed tablets by enhancing the dissolution rate

Abstract

In the present work, studies design, formulation development and evaluation of immediate release tablets of Lercanidipine inclusion complex with a view to improve its aqueous solubility, dissolution rate and oral bioavailability.The inclusion complexes of Lercanidipine were prepared with β-cyclodextrin by physical mixture, Kneading method and solvent evaporation method. The complexes were prepared in different molar ratios of drug and β-cyclodextrin namely 1:1M, 1:2M with β-cyclodextrin.The phase solubility diagram for the complex formation between Lercanidipine and β-cyclodextrin in water are AL type. Phase solubility diagram of Lercanidipine with β-cyclodextrin illustrate the solubility enhancement capacity of cyclodextrin. The aqueous solubility of Lercanidipine increased linearly (R2=0.989) as the function of β-cyclodextrin concentration. The stability constant “Kc” was found to be 164.557M-1.Invitro dissolution studies for pure drug and inclusion complexes and prepared tablets were carried out in 900 ml of 0.1N HCL using USP II paddle type dissolution apparatus.It is evident that the complex and tablets prepared were exhibited a faster dissolution when compared to pure drug dissolution data.A marked improvement in the dissolution rates observed with LK2 prepared by Kneading method. The higher dissolution rates observed with inclusion complexes and tablets prepared by Kneading may be due to better interaction of drug β- cyclodextrin. The prepared complexes were characterized by FT-IR Studies.The inclusion complex of Lercanidipinei.e.LK2 complex and F6 tablets containing LK2 complex were subjected to short-term stability studies by storing them at room temperature and at 400C and relative Humidity of 75%RH. The samples were analyzed at an interval of one week, three weeks and six weeks for their physical appearance, drug content values and dissolution profiles. No appreciable changes observed with the above parameters.