Formulation Development and Evaluation of Sublingual Tablets of Enalapril Maleate Using Co-processed Superdisintegrants

Abstract

Enalapril Maleate is anti-hypertensive drug and its oral bioavailability is 40%. Sublingual tablets of Enalapril Maleate were prepared to improve its bioavailability, to avoid pre-systemic metabolism and hepatic first pass elimination. Tablets were prepared by wet granulation technique using two different superdisintegrants KYRON-T-314 and INDION-414 in the different ratio (1:1, 1:2 and 2:1) by co-processing and physical mixing. FTIR (Fourier transform infrared spectroscopy) and DSC (differential scanning calorimetry) spectroscopic studies indicated that there are no drug-excipient interactions. Tablets were evaluated for precompression as well as post-compression parameters, such as weight variation, thickness, hardness, friability, in vitro disintegration time, wetting time, in vitro dispersion time, water absorption ratio, drug content, in vitro drug release study and ex-vivo permeation study. The result showed that the formulation containing co-processed superdisintegrant in the ratio of 1:2 (CP2) showed faster disintegration, wetting, dispersion and maximum drug release. The disintegration time of optimized formulation (CP2) was up to 7 sec. The % in vitro drug release of Enalapril Maleate was 100.52% in 3 min. Ex vivo permeation of CP2 was found to be 92.26±0.96% in 6 min. Formulation CP2 was subjected to stability studies for 3 months at 40±5ºC/75±5%RH. Tablets didn’t reveal any appreciable changes. From the present work it reveals that the co-processed superdisintegrants formulation are superior to physical mixture formulation. Sublingual tablets of Enalapril Maleate gives faster drug release because of presence of superdisintegrants and may improve bioavailability of Enalapril Maleate.

Keywords: Enalapril Maleate, sublingual tablet, KYRON-T-314, INDION-414,

co-processed superdisintegrant