DESIGN AND DEVELOPMENT OF ROXITHROMYCIN FAST DISSOLVING TABLETS

Background: Roxithromycin is a semi-synthetic macrolide antibiotic with very low aqueous solubility, making dissolution an important formulation challenge. Fast dissolving tablets (FDTs) can provide rapid disintegration in the oral cavity without water and may improve convenience for patients who have difficulty swallowing conventional tablets. Objective: The study aimed to develop and evaluate Roxithromycin fast dissolving tablets using a solid-dispersion approach with PEG 4000 and different superdisintegrants, including sodium starch glycolate, croscarmellose sodium and Gum Karaya. Methods: Preformulation studies included organoleptic examination, solubility testing, loss on drying, melting-point determination, UV spectrophotometry and FTIR analysis. Roxithromycin–PEG 4000 physical mixtures and solid dispersions were prepared at drug: polymer ratios of 1: 1, 1: 2 and 1: 3. Tablets equivalent to 150 mg Roxithromycin were prepared by direct compression and evaluated for powder-flow properties, thickness, hardness, friability, weight variation, drug content, disintegration and in-vitro dissolution. Results: Roxithromycin was soluble in methanol and ethanol and sparingly soluble in water, phosphate buffer pH 6.8, 0.1 N HCl, 0.1 N NaOH and chloroform. Loss on drying was 0.175 ± 0.005% and melting point was 118–120°C. The reported 1: 1 drug: PEG 4000 solid dispersion was selected for subsequent tablet development. Powder blends showed bulk density of 0.354–0.368 g/mL, tapped density of 0.458–0.472 g/mL, Carr’s index of 20.306–23.377% and Hausner’s ratio of 1.255–1.305. Tablet hardness was 3.2–3.4 kg/cm², friability 0.685–0.821%, thickness 2.8–2.9 mm and drug content 98.45–99.74%. Formulation F5 showed the shortest reported disintegration time (62 ± 4 s). The source document reports a release-kinetic analysis for batch F7, with R² values of 0.992, 0.946, 0.999 and 1.000 for zero-order, first-order, Higuchi and Korsmeyer–Peppas models, respectively. Conclusion: The study demonstrates the feasibility of combining PEG 4000 solid dispersion with rapid-disintegrating excipients to develop a Roxithromycin FDT. The formulation showed acceptable physical quality and rapid disintegration. However, the source document contains a batch-label discrepancy between the optimized F5 formulation and the subsequent F7 release-kinetic section; this should be verified against the original laboratory records before publication.