Formulation, In-vitro and In-vivo X-ray evaluation of sustained release matrix tablets of Diltiazem HCL using hydrophilic hydrophobic polymer blend

Abstract

The SR matrix tablets were formulated by directly compressible hydrophilic hydrophobic polymeric blend of HPMC K100LV and Eudragit L100-55. Here Diltiazem hydrochloride was used as model drug. Tablets were prepared by direct compression method. The pre and post compression parameters were evaluated. Drug polymer interaction was checked by comparing the FTIR spectra of the physical mixture of drug with the excipients used with pure drug. This established the stability of the drug in the formulation which was further confirmed by Differential Scanning Calorimetry thermograms. Formulation was optimized on the basis of acceptable tablet properties and in vitro drug release. The results of dissolution studies indicated that formulation F11 the most successful of the study, exhibited drug release pattern very close to marketed product release profile. The mechanism of drug release from F11 was diffusion coupled with erosion (anomalous). Scanning electron microscopy was used to visualize the effect of dissolution medium on matrix tablet surface. In vivo X-ray studies were conducted by X-ray analysis which shows sustaining activity by adhering to various sites in the gastrointestinal tract. The long term stability results show no significant change in the dissolution profile. In conclusion, SR matrix tablet formulation is successfully formulated which can lead to improve efficacy and better patient compliance