Preparation, Oral SNEDDS Formulation, and In Vivo Evaluation of the HIV-1 Latency-Reversing Agent EK-16A

Background/Objectives: AIDS is a serious threat to human health and remains incurable; however, EK-16A, an ingenol derivative, shows promise as a functional cure. In this study, we aimed to extract EK-16A from Euphorbia kansui, used in traditional Chinese medicine, to develop an oral self-nanoemulsifying drug delivery system (SNEDDS) for EK-16A and evaluate it in vivo. Methods: EK-16A was purified by SFC combined with conventional extraction. The optimal SNEDDS formulation was selected by emulsification and stability testing. Pharmacokinetics, metabolomics, and proteomics were used for in vivo evaluation. Results: 1. The extraction yield of EK-16A was four times higher than that of the conventional process; the extraction scale was increased by 25 times, and the purity of EK-16A reached 98.0%. 2. EK-16A is a BCS Class IV compound with low solubility and permeability. The compound's content degraded to 49.8% after 3 months at 25 °C/60% RH. The EK-16A SNEDDS formulation A#1 showed no degradation after 3 months at 40 °C/75% RH. The absolute bioavailability after oral administration of formulation A#1 in rats was 0.445%. 3. The proteomics results showed that EK-16A significantly downregulated the PI3K-AKT signaling pathway in SHIV-infected rhesus macaques. Specifically, all 11 identified differential proteins were significantly downregulated. Conclusions: 1. The extraction process for EK-16A features high yield, purity and large scale. 2. The SNEDDS formulation enhances the stability of EK-16A and successfully delivers this low-solubility and permeability compound into the systemic circulation. 3. Proteomics analysis revealed that EK-16A significantly downregulates the PI3K-AKT signaling pathway in SHIV-infected rhesus macaques. However, further experiments, such as measuring plasma viremia and cell-associated SHIV RNA, are needed to confirm this mechanism.