لخّصلي

Eighteen amino acid esters of acyclovir were synthesized as potential prodrugs intended for oral administration and the hydrolytic activation of these prodrugs was shown to be catalyzed by biphenyl hydrolase; an enzyme exists in epithelial cells [25].This is corresponding to 54% of absolute acyclovir [27], after its libration by an extensive enzymatic hydrolysis in the bloodValacyclovir hydrochloride is the L-valyl amino acid ester of the anti viral agent acyclovir [26].

Eighteen amino acid esters of acyclovir were synthesized as potential prodrugs intended for oral administration and the hydrolytic activation of these prodrugs was shown to be catalyzed by biphenyl hydrolase; an enzyme exists in epithelial cells [25]. Valacyclovir hydrochloride is the L-valyl amino acid ester of the anti viral agent acyclovir [26]. The L-valine promoiety severs two purposes: (i) enhanced chemical stability at physiological pH of the prodrug, which is a vital to allow for long term storage and (ii) L-valine promoiety provides an acceptable hydrophilic lipophilicty balance that is essential to achieve a desirable blood levels of acyclovir after oral administration, this is actually attained by valacyclovir [18]. An enhancement of 3-10 fold in oral bioavailability is achieved utilizing this promoiety compared to that of the parent drug, acyclovir. This is corresponding to 54% of absolute acyclovir [27], after its libration by an extensive enzymatic hydrolysis in the blood