In the present study, a naturally occurring clay mineral, Montmorillonite, (Mt) has been explored as a carrier for an antihypertensive drug,
atenolol. The effect of pH, time and initial drug concentration on drug loading capacity of Mt has been evaluated. The adsorption isotherm
was fitted by the Langmuir model and follows the pseudo-second-order kinetics. The synthesized Mt-atenolol complexes were
characterized by XRD, FTIR, TGA, DSC etc. XRD data indicates the intercalation of atenolol within the Mt layers. The release profile of
the atenolol from Mt-atenolol complexes is compared with the pure atenolol, in simulated gastric and intestinal fluids. The release
behaviour of atenolol from Mt-atenolol complexes appears to be in sustained manner over a period of 24 hours and reaches upto 40% and
27% in simulated gastric and intestinal fluids respectively. As compared to pure atenolol, extended gastric retention time was observed for
Mt-atenolol complexes indicative of the increased extent of absorption and bioavailability of the drug. Various kinetic models were used to
elucidate the drug release mechanism, the best fitting was found for Higuchi and Korsmeyer-Peppas model. The synthesized Mt-atenolol
complexes have the potential for developing in to a sustained release formulation for oral drug delivery. Thus, proposing a promising
formulation for oral sustained drug delivery of atenolol.
Key words: Atenolol, Montmorillonite, Adsorption isotherm, Sustained delivery
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