Improved Voriconazole Topical Delivery by Nanoparticles (Minireview)

Ultrasonic Preparation of Nano-CaCO3 Templates and Hollow Mesoporous SiO2 Nanoparticles for Voriconazole Loading

CaCO3 nanoparticles (nano-CaCO3) as nano-templates were prepared using CaCl2 and Na2CO3 solutions under controlled sonication (19.5 kHz). Using the same ultrasonic device, subsequently, hollow mesoporous silica nanoparticles (HMSNs) were obtained by the hard template of nano-CaCO3. HMSNs were selected as carriers for the antifungal drug voriconazole (VOR) loading to overcome poor water solubility. Three-dimensional CaCO3 nanosheets HMSNs were obtained under gentle sonication. Three-dimensional CaCO3 nanosheets of 24.5 nm (hydrodynamic diameter) were obtained under 17.6 W for 3 min. HMSNs were synthesized by double-template method with nano-CaCO3 as the hard template. Transmission electron microscopy measurements showed that the prepared HMSNs possess hollow structures with particle size between 110 and 120 nm. Nitrogen physisorption at -196 °C revealed that the HMSNs had high surface area (401.57 m2/g), high pore volume (0.11 cm3/g), and uniform pore size (2.22 nm) that facilitated the effective encapsulation of VOR in the HMSNs. The loading capacity of VOR (wt%) on the HMSNs was 7.96%, and the total VOR release amount of VOR-HMSNs material was 71.40% at 480 min. The kinetic model confirmed that the release mechanism of HMSNs nanoparticles followed Fickian diffusion at pH = 7.4 and 37 °C. Moreover, the cumulative VOR release at 42 °C (86.05%) was higher than that at 37 °C (71.40%). The cumulative release amount of VOR from the VOR-HMSNs material was 92.37% at pH = 5.8 at the same temperature. Both nano-CaCO3 templates and HMSNs were prepared by sonication at 19.5 kHz. The as-prepared HMSNs can effectively encapsulate VOR and released drug by Fickian diffusion.

Study on the regulation mechanism of effective glass transition temperature on the crystallization of crystalline solid dispersion

The focus of this investigation was to determine the mechanism of effective glass transition temperature (TgE) on the crystallization behavior and microstructure of drugs in crystalline solid dispersion (CSD). CSDs were prepared by rotary evaporation using ketoconazole (KET) as a model drug and the triblock copolymer poloxamer 188 as a carrier. The pharmaceutical properties of CSDs, such as crystallite size, crystallization kinetics, and dissolution behavior, were investigated to provide a foundation for studying the crystallization behavior and the microstructure of drugs in CSDs. According to classical nucleation theory, the relationship of treatment temperature-drug crystallite size-TgE of CSD was investigated. Voriconazole, a compound that is structurally similar to KET but with different physicochemical properties, was used to verify the conclusions. The dissolution behavior of KET was significantly enhanced compared to the raw drug due to smaller crystallite size. Crystallization kinetic studies revealed a two-step crystallization mechanism for KET-P188-CSD, in which P188 crystallized first and KET crystallized later. When the treatment temperature was near TgE, the drug crystallite size was smaller and more numerous, which suggests nucleation and slow growth. With the increase of temperature, the drug changed from nucleation to growth, and the number of crystallites decreased and the size of the drug increased. This result suggests it is possible to prepare CSDs with higher drug loading and smaller crystallite size by adjusting the treatment temperature and TgE, so as to maximize the drug dissolution rate. The VOR-P188-CSD maintained a relationship between treatment temperature, drug crystallite size, and TgE. The findings of our study demonstrate that TgE and the treatment temperature can be used to regulate the drug crystallite size and improve the drug solubility and dissolution rate.

Nanodiamond applications in skin preparations

The biocompatibility and nontoxicity of nanodiamonds (NDs) in combination with their excellent physical performance have rendered them attractive candidates for biomedical applications. NDs have great potential in drug nanoformulations because of their small size compared with other carbon nanomaterials. They are nontoxic with excellent adsorption properties and can be formulated into skin care products. Even though NDs have shown encouraging potential in skin preparations, only a few studies have reviewed their application in topical drug delivery systems. Therefore, here we focus on the application of NDs in skin care preparations, skin cancer medication, and wound healing. We also highlight the development of topical drug delivery by NDs and their cytotoxicity.

Solid lipid nanoparticles for antifungal drugs delivery for topical applications

Systemic and local infections caused by fungi, in particular those concerning the skin and nails, are increasing. Various drugs are used for mycoses treatment such as amphotericin B, nystatin and ketoconazole, fluconazole, itraconazole and fluconazole, among others. Unfortunately, many of these antifungal agents can cause side effects such as allergic and severe skin reaction. With the aim to reduce these side effects and maximize the antifungal drug activity, various drug-delivery systems have been formulated and been investigated in the last few years. In this context, solid lipid nanoparticles are attracting great attention. The aim of this review is to highlight the role of solid lipid nanoparticles as carriers of antifungal drugs for topical applications.