Background: Buchanania lanzan gum, better known as chironji gum, has been traditionally used as a binder in food preparations. Water-soluble polysaccharides have good emulsifying properties, but the polysaccharide structure elucidation of water soluble chironji gum has not been carried out, and also, its use in emulsion has not been explored. Objectives: The aim of this study is to perform structural characterization of water-soluble polysaccharide isolated from chironji gum (CGPS) and explore its nanoemulsifying properties. Materials and Methods: The water-soluble polysaccharide CGPS was isolated and fractionated by Sepharose 6B column. Structural characterization was investigated by high-performance liquid chromatography (HPLC), nuclear magnetic resonance (NMR), and gas chromatography–mass spectrometry (GC–MS). CGPS-stabilized nanoemulsion was formulated using Miglyol 812, Cremophor RH40, and diclofenac sodium and was evaluated. Results: The polysaccharide fraction had a yield of 33.85% ± 0.88% w/w. HPLC analysis revealed that CGPS consisted of galactose, rhamnose, arabinose, and glucose. CGPS had an average molecular weight of 201 kDa. Analytical studies, including NMR and GC–MS, showed that CGPS had repeating units of → 4)-α-d-Galp (1 → 2)-α-l-Rhap-(1 → with terminal β-d-Glcp (1 → and α-l-Araf (1 → residues. The nanoemulsions prepared with CGPS showed a droplet size ranging from 31.41 ± 0.26 to − 65.30 ± 0.21 nm, and negative zeta potential values were obtained for all the nanoemulsions. In vitro drug release studies of the CGPS nanoemulsion formulation revealed that diclofenac sodium release was delayed in simulated colonic fluid. Conclusion: This study indicates immense potential of CGPS for colon-targeted drug delivery system.