Current Drug Delivery - Online First

Tetrandrine (TET) has multiple pharmacological activities, but its water solubility is poor, which is the main reason for its low bioavailability.

The purpose of this study was to prepare TET nanocrystals (TET-NCs) using a grinding method to enhance the dissolution rate and ultimately improve the bioavailability of TET.

TET-NCs were synthesized via media milling, employing Poloxam 407 (P407) as surface stabilizers and mannitol as a cryoprotectant during freeze-drying. The crystal structure, particle diameter, and zeta potential were characterized using differential scanning calorimetry (DSC), Fourier-transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), and X-ray diffraction (XRD). The in vitro release behavior and pharmacokinetics of TET-NCs were assessed. The cytotoxicity of TET and TET-NCS on RAW264.7 cells was determined by the CCK-8 method.

The particle size of TET-NCs was 360.0±7.03 nm, PDI was 0.26±0.03, and zeta potential was 6.64±0.22 mV. The cumulative dissolution within 60 minutes was 96.40±2.31%. The pharmacokinetic study showed that AUC0-72 h and Cmax of TET-NCs were significantly enhanced by 3.07 and 2.57 times, respectively, compared with TET (p<0.01). TET-NCs significantly increased the cell inhibition on RAW264.7 cells compared to the TET (P<0.01).

The preparation of TET-NCs enhanced dissolution rate and bioavailability significantly, and it also improved the inhibition effect of RAW264.7 cells.

Fungal keratitis (mycotic keratitis) is an eye infection in which the cornea is infected by fungi and such fungal keratitis management can be effectively possible by ocular administration of antifungal drugs.

The main objectives of the present research were to develop and evaluate fluconazole-loaded transfersomal hydrogels for ocular delivery in the effective management of fungal keratitis.

A 2³ factorial design-based approach was used for statistical optimization, where (A) the ratio of lipid to edge activators, (B) the amount of hyaluronic acid (% HA), and (C) the ratio of edge activators (sodium deoxycholate to Span 80) were taken as three factors. The average vesicle diameter (Z, nm) of transfersomes was taken as a response. Further, fluconazole-loaded transfersomes (FTO) were incorporated into 1% Carbopol 940-based hydrogel (OF1) and 2% HMPC K4M-based hydrogel (OF2) containing D-panthenol (5% w/w).

The optimal variable setting for the optimized formulations of FTO was (A) = 9.15, (B) = 0.30%, and (C) = 3.00. FTO exhibited 66.39 nm Z, 0.247 polydispersity index, – 33.10 mV zeta potential, and 65.38 ± 1.77% DEE, and desirable elasticity. TEM image of FTO demonstrated a unilamellar vesicular structure. The ex vivo ocular permeation of fluconazole from transfersomal hydrogels was sustained over 24 h. All the transfersomal hydrogels showed good bioadhesion and excellent antifungal activity with respect to the zone of inhibition against Candida albicans than Aspergillus fumigates, in vitro. HET-CAM study results demonstrated that both the hydrogels were non-irritant and safe for ocular. Short-term physical stability study suggested the stability of the developed formulation.

The current research demonstrated a new way to enhance the ocular penetration of fluconazole via transfersomal hydrogel formulations for ocular delivery in the effective management of fungal keratitis.

The last strategy in targeted drug delivery systems is to deliver the anticancer drug to the tumor tissue to increase its therapeutic effect and minimize its undesirable side effects. In line with this goal in this research, the redox/pH-responsive disulfide magnetic nanocarriers based on PF127-NH2/L-cysteine-CM-β-CD-FA were synthesized and evaluated in a doxorubicin delivery system.

We effectively surrounded Fe3O4 nanoparticles with SiO2 using the sol-gel method, and then confidently coated them with oleic acid on Fe3O4@SiO2 nanoparticles.. In another reaction, a PF127-NH2/L-cysteine-CM-β-CD-FA was synthesized. The process involved modifying pluronic F127 (PF 127) with maleic anhydride and aminating it to form PF127-NH2. The obtained PF127-NH2 was attached to L-cysteine, followed by condensing with carboxymethyl-β-cyclodextrin and then functionalized by folic acid. Finally, PF127-NH2/L-cysteine-CM-β-CD-FA was coated on the surface of magnetic nanoparticles, and the resulting PF127-NH2/L-cysteine-CM-β-CD-FA was disulfidated to form the final nanocarrier network, which was abbreviated as LCMNPs-SS. The doxorubicin was used as a model drug and loaded into the LCMNPs-SS nanocarrier.

The LCMNPs-SS nanocarrier exhibited excellent properties for controlled release, with a well-defined release rate, a controllable level by an external magnet, and adjusting by DL-dithiothreitol concentration. The LCMNPs-SS nanocarrier could also break apart when exposed to an oxidant or a change in pH. This meant that the drug release could be fine-tuned in response to temperature, pH, or more than one stimulus.

These drug-carrying systems are valuable in reducing the dose of doxorubicin. High internalization of the synthesized LCMNPs-SS caused sped cellular uptake.