PURPOSE: A nanoparticle containing a hydrophobic drug in a hyaluronic acid-bile acid complex is provided to ensure excellent anticancer effect and to be used as a novel drug delivery system for treating cancer. CONSTITUTION: A low molecular hyaluronic acid-bile acid complex is an amphiphilic complex in which hydrophobic bile acid is conjugated to low molecular hyaluronic acid and forms a self-aggregation in the water. The hydrophobic bile acid is 5-beta-cholanic acid, cholic acid, chenodeoxycholic acid, glycocholic acid, taurocholic acid, deoxycholic acid, lithocholic acid, or 7-oxo-lithocholic acid. The complex is prepared by covalent bond of amino ethyl 5-beta cholanoamide to the low molecular hyaluronic acid.본 발명은 5 내지 20 KDa의 저분자량 히알루론산에 소수성 담즙산이 결합되어 수중에서 자기 집합체(self-aggregation)를 형성하는 히알루론산-담즙산 복합체, 상기 복합체 내부에 소수성 약물이 봉입된 나노입자, 그 나노입자를 포함하는 주사제, 및 그 나노입자의 제조방법을 제공한다.
