Niosomal formulation of mefenamic acid for enhanced cancer targeting; preparation, characterization and biodistribution study using radiolabeling technique.

BACKGROUND: This work aimed to prepare niosomal formulations of an anticancer agent [mefenamic acid (MEF)] to enhance its cancer targeting. 131I was utilized as a radiolabeling isotope to study the radio-kinetics of MEF niosomes. METHODS: niosomal formulations were prepared by the ether injection method and assessed for entrapment efficiency (EE%), zeta potential (ZP), polydispersity index (PDI) and particle size (PS). MEF was labeled with 131I by direct electrophilic substitution reaction through optimization of radiolabeling-related parameters. In the radio-kinetic study, the optimal 131I-MEF niosomal formula was administered intravenously (I.V.) to solid tumor-bearing mice and compared to I.V. 131I-MEF solution as a control. RESULTS: the average PS and ZP values of the optimal formulation were 247.23 ± 2.32 nm and - 28.3 ± 1.21, respectively. The highest 131I-MEF labeling yield was 98.7 ± 0.8%. The biodistribution study revealed that the highest tumor uptake of 131I-MEF niosomal formula and 131I-MEF solution at 60 min post-injection were 2.73 and 1.94% ID/g, respectively. CONCLUSION: MEF-loaded niosomes could be a hopeful candidate in cancer treatment due to their potent tumor uptake. Such high targeting was attributed to passive targeting of the nanosized niosomes and confirmed by radiokinetic evaluation.

Radioiodinated acemetacin loaded niosomes as a dual anticancer therapy.

A niosomal formula of acemetacin was developed to improve its tumor targeting and radio-kinetic evaluation was performed using 131I. Niosomes were prepared by ether injection method and characterized for particle size (PS), polydispersity index (PDI), zeta potential (ZP), entrapment efficiency (EE%) and in vitro drug release. Factors affecting radiolabeling with 131I were studied and optimized. Radio-kinetic evaluation was done for 131I-ACM optimum niosomal formula by intravenous (I.V) administration to solid tumor bearing mice and compared to I.V 131I-ACM solution as a control. The average droplet size, zeta potential and in vitro release after 24 h for the optimum formula were 315.23 ± 5.37 nm, -9.16 ± 2.91 and 76 %, respectively. The greatest labeling yield of 131I-ACM was 93.1 ± 1.1 %. Radio-kinetic evaluation showed a maximum tumor uptake of 5.431 %ID/g for 131I-ACM niosomal formula and 2.601 %ID/g for 131I-ACM solution at 60 min post I.V. injection. As a conclusion, niosomal formula increased tumor uptake of ACM by passive targeting of the nanosized niosomes. In addition, chemotherapeutic effect of ACM and radiotherapeutic effect of 131I were successfully combined in one treatment regimen using 131I-ACM niosomes which could be used as a hopeful dual anticancer therapy.