Compatibility and stability of paclitaxel combined with doxorubicin hydrochloride in infusion solutions

Engineered Hybrid Vesicles and Cellular Internalization in Mammary Cancer Cells

Extracellular vesicles play an important role in intercellular communication, with the potential to serve as biomaterials for nanocarriers. Combining such extracellular vesicles and liposomes results in advanced drug delivery carriers. In this study, we attempted to fabricate hybrid vesicles using a membrane fusion method and incorporated an anticancer drug. As a result, we successfully prepared nanosized uniform hybrid vesicles and evaluated their physicochemical characteristics and intracellular uptake mechanisms via endocytosis in various cell lines. Compared to liposomes, the hybrid vesicles showed better physical properties and a relatively higher reduction in cell viability, which was presumably dependent on the specific cell type. These findings suggest that fusion-based hybrid vesicles offer a novel strategy for delivering therapeutic agents and provide insights into the types of extracellular vesicles that are useful in fabricating hybrid vesicles to develop an advanced drug delivery system.

Preparation, characterization and in vitro cytotoxicity of paclitaxel-loaded sterically stabilized solid lipid nanoparticles

In an effort to develop an alternative formulation of paclitaxel suitable for parenteral administration, paclitaxel-loaded sterically stabilized solid lipid nanoparticles (SLNs) were prepared, characterized and examined for in vitro cytotoxicity. The SLNs, comprising trimyristin (TM) as a solid lipid core and egg phosphatidylcholine and pegylated phospholipid as stabilizers, were prepared using a hot homogenization method. Regardless of paclitaxel loading, the particle sizes and zeta potentials of the prepared SLNs were around 200nm and -38mV, respectively, suggesting that they would be suitable as a parenteral formulation. Cryo-scanning electron microscopy showed that the SLNs were homogeneous and spherical in shape, while differential scanning calorimetry measurement of the melting peak revealed that the TM exists as a solid in our formulation. Paclitaxel was loaded to the solid cores at a w/w ratio of 6%. Gel column chromatography showed that paclitaxel co-eluted with the phospholipids, indicating that paclitaxel was incorporated in the SLNs. An in vitro drug release study showed that paclitaxel was released from the SLNs in a slow but time-dependent manner. Furthermore, treatment of the OVCAR-3 human ovarian cancer cell line and the MCF-7 breast cancer cell line with paclitaxel-loaded SLNs yielded cytotoxicities comparable to those of a commercially available Cremophor EL-based paclitaxel formulation. These results collectively suggest that our optimized SLN formulation may have a potential as alternative delivery system for parenteral administration of paclitaxel.

Effect of Freezing, Long-Term Storage, and Microwave Thawing on the Stability of Ketorolac Tromethamine

BACKGROUND:

Ketorolac tromethamine is a nonsteroidal agent with potent analgesic and moderate antiinflammatory activity. Advance preparation of intravenous solution could be useful to improve quality assurance, time management, and cost-savings of drug delivery.

Objective:

To investigate the effect of freezing, long-term storage, and microwave thawing on the stability of ketorolac tromethamine in dextrose 5% infusion.

METHODS:

Five polyolefin bags of solution containing ketorolac tromethamine 20 mg per 100 mL of dextrose 5% were frozen for 3 months at −20 °C, thawed in a microwave oven with a validated cycle, and stored at 4 °C. The concentration of ketorolac was measured by HPLC. Visual inspection and pH measurement were also carried out.

RESULTS:

No color change or precipitation was observed. Ketorolac was stable for at least 60 days under refrigeration after freeze–thaw. Throughout this period, the lower confidence limit of the estimated regression line of the concentration–time profile remained >90% of the initial concentration, and the pH value decreased slightly without affecting chromatographic parameters.

CONCLUSIONS:

Within these limits, ketorolac tromethamine in dextrose 5% infusion may be prepared and frozen in advance by a centralized intravenous admixture service, then thawed before use in clinical units.

Effect of the Freezing Conditions and Microwave Thawing Power on the Stability of Cefuroxime in Dextrose 5% Infusion Polyolefin Bags at 4 °C

BACKGROUND

Intravenous cefuroxime sodium solution could be prepared in advance by a centralized hospital pharmacy service to improve safety and time management.

OBJECTIVE

To investigate the effect of freezing and microwave thawing on the solution stability of cefuroxime.

METHODS

Cefuroxime 1.5 g in 100 mL of dextrose 5% in polyolefin bags was frozen individually (group A) or in one package (group B) for 98 days at −20 °C. The solutions were then thawed using microwaves at 270 (light cycle) or 800 watts (hard cycle) and stored at 4 °C. The cefuroxime concentration was measured by HPLC. Visual inspection was performed and pH was measured at that time. Stability of the solution was defined as a concentration remaining superior to 90% of the initial concentration by regression analysis.

RESULTS

No color change or precipitation in the solutions was observed. In group A, stability was at least 23 and 21 days after light and hard cycle thawing, respectively. In group B, stability was at least 21 and 18 days, respectively, with the pH increasing without affecting chromatographic parameters.

CONCLUSIONS

The optimal conditions for advance preparation of a solution containing cefuroxime 1.5% in dextrose 5% may be freezing of individual containers followed by a light cycle of microwave thawing.

Targeted antiproliferative drug delivery to vascular smooth muscle cells with a magnetic resonance imaging nanoparticle contrast agent: implications for rational therapy of restenosis

BACKGROUND

Restenosis is a serious complication of coronary angioplasty that involves the proliferation and migration of vascular smooth muscle cells (VSMCs) from the media to the intima, synthesis of extracellular matrix, and remodeling. We have previously demonstrated that tissue factor-targeted nanoparticles can penetrate and bind stretch-activated vascular smooth muscles in the media after balloon injury. In the present study, the concept of VSMC-targeted nanoparticles as a drug-delivery platform for the prevention of restenosis after angioplasty is studied.

METHODS AND RESULTS

Tissue factor-targeted nanoparticles containing doxorubicin or paclitaxel at 0, 0.2, or 2.0 mole% of the outer lipid layer were targeted for 30 minutes to VSMCs and significantly inhibited their proliferation in culture over the next 3 days. Targeting of the nanoparticles to VSMC surface epitopes significantly increased nanoparticle antiproliferative effectiveness, particularly for paclitaxel. In vitro dissolution studies revealed that nanoparticle drug release persisted over one week. Targeted antiproliferative results were dependent on the hydrophobic nature of the drug and noncovalent interactions with other surfactant components. Molecular imaging of nanoparticles adherent to the VSMC was demonstrated with high-resolution T1-weighted MRI at 4.7T. MRI 19F spectroscopy of the nanoparticle core provided a quantifiable approach for noninvasive dosimetry of targeted drug payloads.

CONCLUSIONS

These data suggest that targeted paramagnetic nanoparticles may provide a novel, MRI-visualizable, and quantifiable drug delivery system for the prevention of restenosis after angioplasty.