In this study, we investigated the formulation of stable solid dispersions to enhance the bioavailability of olaparib (OLA), a therapeutic agent for ovarian cancer and breast cancer characterized as a BCS class IV drug with low solubility and low permeability. Various polymers were screened based on solubility tests, and OLA-loaded solid dispersions were prepared using spray drying. The physicochemical properties of these dispersions were investigated via scanning electron microscopy (SEM), differential scanning calorimetry (DSC), powder X-ray diffraction (PXRD), and Fourier Transform Infrared Spectroscopy (FT-IR). Subsequent dissolution tests, along with assessments of morphological and crystallinity changes in aqueous solutions, led to the selection of a hypromellose (HPMC)-based OLA solid dispersion as the optimal formulation. HPMC was effective at maintaining the supersaturation of OLA in aqueous solutions and exhibited a stable amorphous state without recrystallization. In an in vivo study, this HPMC-based OLA solid dispersion significantly enhanced bioavailability, increasing AUC_0–24 by 4.19-fold and C_max by more than 10.68-fold compared to OLA drug powder (crystalline OLA). Our results highlight the effectiveness of HPMC-based solid dispersions in enhancing the oral bioavailability of OLA and suggest that they could be an effective tool for the development of oral drug formulations.

Background: Onychomycosis responds poorly to topical therapy, and efinaconazole (EFN) has low aqueous solubility. Methods: This study aimed to develop a 10% w/w EFN self-nanoemulsifying system (SNEDDS) with improved solubility, permeation, antifungal activity, and stability. Excipients were screened by EFN saturation solubility. An MCT oil/Solutol HS 15/Labrafil M2125 CS SNEDDS (5/75/20, w/w) was optimized via a pseudo-ternary diagram. Characterization included droplet size, PDI, and zeta potential, morphology, and drug–excipient compatibility. Solubility was measured across pH. Permeation of EFN SNEDDS vs. EFN suspension was tested by Franz diffusion cells. Antifungal activity against Trichophyton rubrum and Trichophyton mentagrophytes was assessed by paper-disc diffusion, and hyphal damage on human nails was examined by SEM. Stability was studied for six months under room, accelerated, and stress conditions. Results: The optimized SNEDDS formed sub-50 nm droplets with low polydispersity and favourable zeta potential. Solubility was maintained across pH, and cumulative permeation increased 13.6-fold versus suspension. Paper-disc assays showed larger inhibition zones at lower EFN doses. SEM on human nails revealed marked hyphal destruction. TEM confirmed spherical nanoemulsion droplets. FT-IR showed no new peaks, supporting compatibility. Particle size, PDI, zeta potential, and drug content remained stable over six months under all storage conditions. Conclusions: A 10% w/w EFN SNEDDS enhanced solubility, transungual permeation, and antifungal efficacy while maintaining robust stability, supporting its potential as an ethanol-free therapy for onychomycosis.