maxmaxmaxA water soluble gel polymer matrix comprising hyaluronic acid and an antitumor agent is described herein. The antitumor agent is crosslinked with the hyaluronic acid by at least one of covalent and/or non covalent bonding resulting in improved water solubility of the antitumor agent. Pharmacokinetic studies illustrated that the antitumor agent exhibits enhanced C (maximum drug plasma concentration) and T (time required to reach C) values.