The effect of fatty acids on the rectal absorption of acyclovir in rats

The enhancing effect of fatty acids on the rectal absorption of acyclovir has been evaluated in rats. Acyclovir proved to be absorbed to the extent of 3 to 9% after oral administration. After rectal administration in the absence of absorption-promoter, the bioavailability of acyclovir was 37%. Its rectal administration with 4% sodium caprate resulted in enhanced bioavailability (81 +/- 3%).