Lakhasly

In contrast to methyl esters, ethyl esters are more commonly used as prodrug moieties.This is in contrast to the more polar antiviral zanamivir which is administered via the nasal rout.The ethyl ester prodrug oseltamivir; an anti-influenza (anti-viral) agent has an oral bioavailability of nearly 80%, which represents a significant improvement in bioavailability of the parent compound which is nearly 5% [10].As mentioned before, ester prodrugs are generally exploited in order to offer increased lipophlicity to the parent drug; hence an increased intestinal absorption can be achieved.In clinical practice this improvement in bioavailability enables oral administration of oseltamivir.

In contrast to methyl esters, ethyl esters are more commonly used as prodrug moieties. This is mainly due to the low levels of ethanol librated upon cleavage of ester bond and consequently toxicity concerns are not quite significant.
As mentioned before, ester prodrugs are generally exploited in order to offer increased lipophlicity to the parent drug; hence an increased intestinal absorption can be achieved. Ethyl esters are employed to obtain prodrugs with these characteristics. The ethyl ester prodrug oseltamivir; an anti-influenza (anti-viral) agent has an oral bioavailability of nearly 80%, which represents a significant improvement in bioavailability of the parent compound which is nearly 5% [10]. In clinical practice this improvement in bioavailability enables oral administration of oseltamivir. This is in contrast to the more polar antiviral zanamivir which is administered via the nasal rout.
Additional example is ximelagatran, an ethyl ester prodrug of melagatran which acts as thrombin inhibitor (Figure 5). Studies have showed that an 80 fold increase in permeability in caco 2 cells was achieved with this prodrug compared with the active drug melgatran. In addition, the studies revealed that the bioavailability of ximelagatran is 20% in man which represents 2.7 to 5.5 increase in bioavailability over its parent drug, melagatran [7].