The present disclosure relates to a hydrogel composition and a process of preparation thereof. Particularly, the present disclosure relates to an endoscopically injectable, self-assembled polyglycerol stearate (PGS) based hydrogel composition and the process of preparation thereof. The hydrogel composition comprises a plant-based food additive, a fluid medium, a dye and an active agent. The hydrogel composition of the present disclosure is self-assembled hydrogel and can have applications in endoscopic mediated neoplastic lesions removal from the digestive tract.