Incorporation of efavirenz inclusion complex In Dissolvable Microneedle for enhanced effectiveness of intravaginal drug delivery: A proof of concept study

Abstract

Efavirenz (EFV) is one of the first line treatments of HIV infection. EFV is one of non-nucleoside reverse transcriptase inhibitors (NNRTIs) that can inhibit the responsible of reverse transcriptase enzyme for HIV replication. In oral administration, EFV exhibits low bioavailability (30–56 %) problem owing to its poor solubility (0.9 μg/mL). In this research, the poor solubility was overcome by formulating EFV as a complex inclusion (IC)with β-cyclodextrin (β-CD). Furthermore, considering the benefits of vaginal delivery, IC was further incorporated into dissolving microneedle systems (DMN) using polyvinyl alcohol (PVA) and polyvinyl pyrrolidone (PVP) as biocompatible and biodegradable polymes. The results showed that EFV successfully formed IC by the change of the molecular shape with β-CD polymer, confirmed by FTIR and XRD. Importantly, the results showed that the formulation did not cause lysis and irritation on erythrocytes and blood vessels, showing the safety of this approach. Following its incorporation into DMN, IC-DMN could permeate the skin ex vivo as 78.70 ± 14.22 μg/cm3, which was about 3-times higher compared to DMN containing pure EFV and patch control. The in vivo pharmacokinetic study showed that the maximum plasma concentration of IC-DMN was 13.74 ± 2.48 μg/cm3, EFV-oral 6.27 ± 1,13 μg/cm3, vaginal gel 14.83 ± 3.65 μg/cm3. AUC values for each treatment was 147.33 ± 26.62 h μg/mL, 22.33 ± 4.03 h μg/mL, 63.33 ± 11.44 h μg/mL, respectively, indicating that the purpose of this study which was to increase the bioavailability of EFV was succefully achieved. Therefore, this combibation approach could be new alternative to HIV treatment using EFV in woman.