The solid dispersion technique is the most effective and widely used approach for increasing the solubility and release of drugs that have low water solubility. Mirtazapine (MRT) is an atypical antidepressant used to treat severe depression. MRT has a low oral bioavailability (about 50%) due to its low water solubility (BCS class II). The study’s goal was to determine optimum conditions for incorporating MRT into various polymer types utilizing the solid dispersion (SD) technique, with the goal of selecting the most suitable formula with the optimal aqueous solubility, loading efficiency, and dissolution rate. The D-optimal design was used to pick the optimal response. The optimum formula was subjected to physicochemical evaluation by Fourier transform infrared spectroscopy (FT-IR), differential scanning calorimetry (DSC), X-ray powder diffraction (XRPD), and scanning electron microscopy (SEM). In vivo bioavailability study was conducted on white rabbits’ plasma samples. MRT-SDs were prepared by the solvent evaporation method using Eudragit (RL-100, RS-100, E-100, L-100–55), PVP K-30, and PEG 4000 with different drug/polymer percentages (33.33%, 49.99%, and 66.66%). Results showed that the optimum formula obtained using PVP K-30 at a drug percentage of 33.33% gave a loading efficiency of 100.93%, an aqueous solubility of 0.145 mg/ml, and a dissolution rate of 98.12% after 30 min. These findings demonstrated promising enhancement of MRT properties and increasing its oral bioavailability by 1.34-fold more than plain drug. Graphical Abstract

Targeted drug delivery is achieving great success in cancer therapy due to its potential to deliver drugs directly to the action site. Terbinafine hydrochloride (TER) is a broad-spectrum anti-fungal drug that has been found to have some potential anti-tumor effects in the treatment of colon cancer. We aimed here to design and develop pH-sensitive Eudragit (Eud)-coated mesoporous silica nanostructures (MSNs) to control drug release in response to changes in pH. The diffusion-supported loading (DiSupLo) technique was applied for loading TER into the MSNs. The formulation was optimized by a D-optimal design, which permits the concurrent assessment of the influence of drug/MSN%, coat concentration, and MSN type on the drug entrapment efficiency (EE) and its release performance. The optimal formula displayed a high EE of 96.49%, minimizing the release in pH 1.2 to 16.15% and maximizing the release in pH 7.4 to 78.09%. The cytotoxicity of the optimal formula on the colon cancer cells HT-29 was higher than it was with TER alone by 2.8-fold. Apoptosis in cancer cells exposed to the optimum formula was boosted as compared to what it was with the plain TER by 1.2-fold and it was more efficient in arresting cells during the G0/G1 and S stages of the cell cycle. Accordingly, the repurposing of TER utilizing Eud/MSNs is a promising technique for targeted colon cancer therapy.

Background: Skin cancer has become a global health issue because of increasing exposure to environmental contaminants and UV radiation. Terbinafine hydrochloride (TRB), a broad-spectrum antifungal medication, has demonstrated notable anti-tumor properties in previous studies; however, its repurposing for skin cancer therapy remains underexplored. Objective: This study reports for the first time, the development of a new delivery system: a nanoemulsion (NE)–foam hybrid system, i.e., “nanoemulfoam” (NEF), designed to enhance the topical TRB delivery to the skin. The study applied this new hybrid system on TRB for managing skin cancer. Method: The TRB-loaded NEF was produced by loading TRB into a liquid NE. then this was incorporated into a liquid foam base and actuated into foam using a non-propellant mechanism. The NE was developed utilizing peppermint oil as the oil phase and Tween-20/ethanol as the surfactant/co-surfactant combination (Smix). The formulation underwent optimization using the D-optimal design that enabled the simultaneous evaluation of the impact of oil concentration and Tween 20 concentration in the Smix on the particle size (PS), zeta potential (ZP), and dissolution efficiency percent (DE%). Results: The optimal NE formula displayed a small PS of 186.60 ± 2.84 nm, ZP of −13.90 ± 0.99 mV, and DE% of 68.50 ± 1.78% (mean ± SD, n = 3). After incorporation into the foam system, the produced TRB-loaded NEF demonstrated a 7.43-fold increase in the drug transdermal flux in comparison with plain drug foam (p < 0.05). The TRB-loaded NEF showed no signs of inflammation or irritation when applied to abdominal rabbit skin, indicating its safety. The optimum formula exhibited a statistically significant 10-fold increase in cytotoxicity against A-431 skin cancer cells compared to TRB alone, along with a 1.54-fold increase in apoptosis (p < 0.05). Molecular docking studies targeting CDK2, a key regulator of cell proliferation and a known TRB target, revealed that TRB displayed highly favorable binding scores compared to the reference drug. Conclusions: The TRB-loaded NEF represents a promising nanotechnology-based approach for the topical treatment of skin cancer, supporting further investigation toward clinical translation.

Background/Objectives: For hyperlipidemic patients with statin resistance, a fixed-dose combination of a non-statin drug such as ezetimibe (EZT) and bempedoic acid (BA) provides a significant benefit. Although both drugs exhibit poor aqueous solubility, the oral bioavailability of EZT is more critically limited by dissolution, whereas BA maintains adequate absorption due to its high intestinal permeability. With regard to the reference product, Nexlizet^® (180/10 mg), our study focused on developing a novel tablet with superior in vitro performance without incorporating sodium lauryl sulfate (SLS), as it may potentially alter BA absorption. Methods: The solid dispersion technique (co-precipitation) was applied using the Kollidon^® VA64 polymer, and the solid state was characterized through differential scanning colorimetry (DSC), X-ray powder diffraction (XRPD), and Fourier transform infrared spectroscopy (FTIR). The prepared solid dispersions (SDs) were formulated into film-coated tablets (FCTs) and were characterized physically and for drug performance, and an animal model study was also conducted. Results: The solid-state analysis of the optimized SD formula (S30) revealed reduced drug crystallinity with no drug–carrier chemical interaction. The optimized formula (F30), a film-coated tablet, successfully achieved comparative in vitro dissolution versus Nexlizet^® and passed the accelerated stability study. Furthermore, in vivo evaluation revealed that F30 significantly reduced serum total cholesterol (TC), triglycerides (TG), and low-density lipoprotein (LDL), with an increase in high-density lipoprotein (HDL), in an animal model. Conclusions: These findings confirm that the SD technique is an effective one-step approach to co-formulating both APIs, simplifying manufacturing processes and optimizing the batch size.