doi:10.1038/nindia.2013.149 Published online 15 November 2013
Researchers have developed a drug carrier based on a complex sugar molecule that can increase the solubility of the blood-pressure-lowering drug telmisartan . They found that telmisartan inhibits the growth of prostate cancer cells.
Blood-pressure-lowering drugs work by blocking cell-membrane receptors known as angiotensin receptors. Previous studies have shown that such receptors are involved in tumour growth, suggesting that angiotensin receptor blockers may be potential anticancer agents. However, the poor solubility of such drugs in intestinal fluid has prevented their therapeutic potential as anticancer agents from being exploited.
To increase the solubility and explore the anticancer effects of telmisartan, the researchers synthesized a drug-delivery complex by loading beta-cyclodextrin, a complex sugar molecule, with telmisartan. The ability of this complex to release telmisartan in simulated intestinal fluid and phosphate buffer saline was studied and compared with that of free telmisartan.
In simulated intestinal fluid, telmisartan bound to the complex showed increased solubility. The complex released significantly higher amounts of the drug than the free drug. Thus, after being released from the complex, telmisartan dissolves in intestinal media, allowing it to be absorbed into the systemic circulation.
The study found that the telmisartan-containing complex inhibited the proliferation of prostate cancer cells at lower concentrations than the free drug. "The use of the drug-carrying complex may improve the bioavailability of telmisartan, suggesting the possibility of using this drug-loaded complex as tablets and capsules for commercial purposes," says Jitender Madan, a senior author of the study.