Radiolabeling of nimesulide with I125 and its biological evaluation in EAC bearing mice

Abstract EN

Labeling of Nimesulide with iodine-125 and its biological evaluation is described.

125I-Nim was prepared by electrophilic substitution of nimesulide with 125I using chloramine-T as an oxidizing agent.

The labeling yield percentage obtained was 95.1% using 200μg Nimesulide, 300 μg chloramine-T and Na125I carrier-free at pH 7 within 1 min as a reaction time.

The labeled drug was stable up to 48 h post labeling.

Biodistribution study of 125I-Nim in tumor bearing mice showed that it is localized in tissues with a high proliferation rate with preferential accumulation in cancerous tissues.

125I-Nim was incorporated rapidly in the tumor site and declined slowly while declined rapidly from other tissues.

In-vitro cell growth inhibition assay stated that the therapeutic activity of 125I-Nim was significantly increased with the increase of radioactivity by decreasing cell surviving fraction when examined on EAC cells.

The percentage survival in tumor bearing mice was the best when starting treatment with 125I-Nim at the third day after inoculation.

It also revealed that locoregional administration of 125I-Nim resulted in higher percentage survival than the intravenous route.

This study may introduce a new radiotherapeutic agent which could be used in tumor imaging and therapy.