Team in Egypt uses nanotechnology for transdermal sildenafil citrate
Avoids side effects and delivers drug quicker into the bloodstream
Researchers at Alexandria University in Egypt believe they may have found a solution to problems with the oral delivery of erectile dysfunction drugs using nanotechnology.
Sildenafil citrate (commonly known as Viagra) is currently the oral drug of choice for erectile dysfunction, despite its numerous side effects, relatively long onset and short duration of action.
Yosna Elnaggar, Magda El-Massik and Ossama Abdallah have carried out tests on different formulations of sildenafil citrate using transdermal nanocarriers, which get the drug into the bloodstream much more quickly than having to swallow a tablet and avoid side effects.
The new method developed by the team, reported in the International Journal of Nanotechnology, could last longer than the oral dosage, of which 70% is wasted when it is metabolised by the liver without having any effect.
Elnaggar says previous attempts to create a Viagra transdermal patch have been hampered by the low oil and water solubility of the drug. However, it is possible to encapsulate the drug in nanoemulsion-based systems, which can readily cross membranes.
The researchers investigated two types of nanocarriers made using fat-like lipid molecules: the first formed an emulsion with the drug using a surfactant compound to allow the lipid molecules and drug to mix, much as soap will emulsify oil and water; the other is a self-emulsifying nanocarrier with its own inbuilt surfactant.
They found that both formulations would have benefits for oral drug delivery, whereas only the nano-emulsion, rather than the self-emulsifying formulation, shows promise for a new Viagra patch.