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Reversible redox system-based drug design, synthesis, and evaluation for targeting nitrogen mustard across brain


Target drug delivery of nitrogen mustard anticancer agents for a brain tumor is still a challenge due to their high hydrophilicity, poor physicochemical properties, and toxicity to normal tissues. The present study is, therefore, an attempt to investigate the possibility of improving the targeting potential and sustained release of nitrogen mustard alkylating agent to brain by employing reversible redox chemical delivery system approach. Various redox derivatives CDS-L-M (4ac) based on dihydropyridine ↔ quaternary pyridinium ion redox system were synthesized and characterized by IR, (1H and 13C)-NMR, and CHN elemental studies. The potential of these CDS derivatives (4ac) to penetrate the blood–brain barrier was computed through an online software program and the values analyzed lay between the ranges those are required for good brain penetration. The results of storage stability study, in vitro chemical oxidation (silver nitrate) and pharmacokinetic studies in human blood, rat blood and brain homogenate for all CDS-L-M (4ac) demonstrated that all derivatives could be oxidized into corresponding quaternary salts at an adequate rate, which suggested that brain targeting could be possible with more stable CDS-L-M (4c). The in vivo study on rats showed that administration of the CDS-L-M (4c) resulted in the sustained level of the corresponding salt (3c) in the brain, while blood levels of the oxidized metabolite rapidly fell. The in vitro NBP alkylating activity of quaternary salt (3c) of CDS-L-M (4c) was comparable to the known drug chlorambucil among all the synthesized derivatives.

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Authors are thankful to the College Managing Committee, SCOP, Nangal for providing necessary facilities to carry out research work. The authors wish to express their gratitude to Dr. Manoj Kumar, Professor of Pharmaceutical Chemistry, UIPS, Panjab University, Chandigarh to carry out an ADME study at his lab. Authors are also thankful to SAIF, Panjab University, Chandigarh for cooperation in getting the spectral data.

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Correspondence to Rajesh K. Singh.

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Singh, R.K., Kumar, S., Prasad, D.N. et al. Reversible redox system-based drug design, synthesis, and evaluation for targeting nitrogen mustard across brain. Med Chem Res 23, 2405–2416 (2014).

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  • Alkylating agent
  • Blood–brain barrier
  • Chemical delivery system
  • ADME
  • NBP assay
  • In vitro/in vivo studies