Psoriatic arthritis is an autoimmune disease of the joints that can lead to persistent inflammation, irreversible joint damage and disability. The current treatments are of limited efficacy and inconvenient. Apremilast (APR) immediate release tablets Otezla® have 20-33% bioavailability compared to the APR absolute bioavailability of 73%. As a result, self-nanoemulsifying drug delivery systems (SNEDDS) of APR were formulated to enhance APR's solubility, dissolution, and oral bioavailability. The drug assay was carried out using a developed and validated HPLC method. Various thermodynamic tests were carried out on APR-SNEDDS. Stable SNEDDS were characterized then subjected to in vitro drug release studies via dialysis membrane. The optimum formulation was F9, which showed the maximum in vitro drug release (94.9%) over 24 h, and this was further investigated in in vivo studies. F9 was composed of 15% oil, 60% Smix, and 25% water and had the lowest droplet size (17.505 ± 0.247 nm), low PDI (0.147 ± 0.014), low ZP (-13.35 mV), highest %T (99.15 ± 0.131) and optimum increases in the relative bioavailability (703.66%) compared to APR suspension (100%) over 24 h. These findings showed that APR-SNEDDS is a possible alternative delivery system for APR. Further studies are warranted to evaluate the major factors that influence the encapsulation efficiency and stability of APR-containing SNEDDS.
Keywords: SNEDDS; apremilast; dissolution; oral bioavailability; pharmacokinetics studies; psoriatic arthritis; solubility.