목적: Currently, the intratympanic drug injection has mainly used as a drug delivery method for the treatment of the inner ear. However, there is a limitation in that the drug permeability through the round window membrane is low and that the drug is rapidly removed by the Eustachian tube. In this study, we aimed to develop an efficient injectable hydrogel formulation using hexanoyl glycol chitosan (HGC), a new class of thermo-sensitive polymer with a sol-gel transition temperature lower than the human body temperature. 방법:We synthesized and used Hexanoyl Glycol Chitosan containing dexamethasone to confirm drug delivery from the guinea pig to the inner ear, and to check the side effects in various ways. 결과:HGC remained in the middle ear cavity of guinea pigs for more than 3 weeks and did not show any side effects in the middle ear and inner ear. In the vivo drug release behavior, the concentration of dexamethasone in the perilymph was significantly increased at 90 minutes after HGC-DEX injection and HGC-DEX showed sustained release for up to 3 days 결론:Due to its low cytotoxicity and long residence time, HGC hydrogel is expected to be useful as a drug delivery formulation for the treatment of inner ear diseases.