Development and Evaluation of Repaglinide Solid Dispersion Tablets using Natural Superdisintegrants

The present study was undertaken to enhance the dissolution characteristics of Repaglinide, a poorly water-soluble antidiabetic drug, by employing the solid dispersion technique combined with natural superdisintegrants. The λmax of Repaglinide in phosphate buffer pH 6.8 was found to be 243 nm. Fourier Transform Infrared (FTIR) spectroscopy was carried out for the pure drug and optimized formulations, confirming the absence of any significant drug–excipient interactions. Solid dispersions were prepared using PEG 4000 as a hydrophilic carrier and further formulated into tablets incorporating natural superdisintegrants such as Ocimum mucilage and Gellan gum. Pre-compression evaluation of the solid dispersion blends indicated good to fair flow properties, with angle of repose below 26.20°, Carr’s index ranging from 11.08 to 18.40, and Hausner’s ratio less than 1.22. Post-compression evaluation revealed that all tablet formulations complied with pharmacopeial limits for weight variation, hardness, friability, thickness, and drug content uniformity. In vitro dissolution studies conducted in phosphate buffer pH 6.8 demonstrated a significant enhancement in drug release from the solid dispersion tablets when compared among formulations. Among all batches, formulation F6 exhibited rapid disintegration and the highest drug release of 99.16% within 45 minutes. The study concludes that the combined approach of solid dispersion and natural superdisintegrants effectively improves the dissolution performance of Repaglinide tablets. Natural superdisintegrants such as Ocimum mucilage and Gellan gum may serve as promising, economical, and biocompatible alternatives to synthetic disintegrants in solid oral dosage forms. Keywords: Repaglinide, Solid dispersion tablets, Natural superdisintegrants, In vitro dissolution, Dissolution enhancement.