An industrial procedure for the intestinal permeability enhancement of acyclovir: in-vitro and histological evidence

Acyclovir, an antiviral drug, has low bioavailability due to its low permeability. Consequently, high drug doses and frequent administration are required. This study investigates the use of span 60, at different concentrations, as a granulating agent to enhance drug permeability using an industrial procedure on a pilot scale. The micromeritics, drug content, drug crystallinity, drug partition coefficient, and drug release of the produced formulations were examined. The findings revealed an enhanced drug partition coefficient, suggesting drug entrapment in the polar portion of span 60. The drug release profiles exhibited rapid and complete drug release. The improvement of the drug permeability was evaluated using a modified non-everted sac technique. Notably, drug permeability through the rabbit intestine significantly improved, as evidenced by various calculated permeation parameters, providing insights into the drug absorption mechanism. The widening of the paracellular pathway was observed through histological examination of the rabbit intestinal segment, which aligns with the drug absorption mechanism. The utilization of a paracellular pathway enhancer as a granulating agent holds promise as a strategy to enhance the oral bioavailability of class III drugs. Overall, this study presents a novel drug delivery approach to enhance drug permeation and bioavailability, with potential implications for other medications.