The present invention relates to a drug delivery system for treating peritonitis, capable of inducing sustained release of a water-soluble drug as well as stably protecting a peritonitis (perforation) site by uniformly mixing an ion complexed water-soluble drug with a mucoadhesive biocompatible polymer, and a method for preparing the same. According to the present invention, the ion complex of a charged water-soluble drug and an ionic compound induces water-insoluble precipitation, and the drug precipitated trough an ion exchange is again slowly dissolved in water in a body liquid containing various ions, so that the drug is not released at the initial stage (within 24 hours) of the application to the locally affected area, but exhibits a sustained release behavior (for one week or longer), thereby enabling effective drug delivery to the locally affected area. In addition, a biocompatible polymer drug carrier according to the present invention has mucoadhesiveness, and thus, when applied to the perforation site, the biocompatible polymer drug carrier stably exists on an induction site without an inconvenient and difficult suturing procedure to protect injury (suppressing the outflow of intestinal materials into the peritoneal cavity/ inducing injury treatment/ suppressing tissue adhesion), and provide an environment in which the ion complexed water-soluble drug can stay in the perforation site, thereby inducing the death of bacteria previously existing in the peritoneal cavity as well as suppressing the invasion of the intestinal bacteria into the peritoneal cavity and thus inducing an easy treatment from a clinician and giving the alleviation of sufferings to a patient through fast treatment.본 발명은 이온 컴플렉스된 수용성 약물을 점막 점착성 생체적합성 고분자에 균일하게 혼합하여, 복막염 (천공) 부위를 안정하게 보호함은 물론 수용성 약물의 서방형 방출을 유도할 수 있는 복막염 치료용 약물 전달 시스템 및 이의 제조방법에 관한 것이다.본 발명에 따르면, 전하를 띠는 수용성 약물과 이온성 화합물의 이온 컴플렉스를 통해 비수용성 침전 (water-insoluble precipitation)을 유도하고, 다양한 이온이 존재하는 체액에서 이온교환을 통해 침전된 약물이 다시 서서히 수
