Determination of paclitaxel in human and rat blood samples after administration of low dose paclitaxel by HPLC-UV detection

pH-Responsive Water-Soluble Chitosan Amphiphilic Core–Shell Nanoparticles: Radiation-Assisted Green Synthesis and Drug-Controlled Release Studies

This work aims to apply water radiolysis-mediated green synthesis of amphiphilic core–shell water-soluble chitosan nanoparticles (WCS NPs) via free radical graft copolymerization in an aqueous solution using irradiation. Robust grafting poly(ethylene glycol) monomethacrylate (PEGMA) comb-like brushes were established onto WCS NPs modified with hydrophobic deoxycholic acid (DC) using two aqueous solution systems, i.e., pure water and water/ethanol. The degree of grafting (DG) of the robust grafted poly(PEGMA) segments was varied from 0 to ~250% by varying radiation-absorbed doses from 0 to 30 kGy. Using reactive WCS NPs as a water-soluble polymeric template, a high amount of DC conjugation and a high degree of poly(PEGMA) grafted segments brought about high moieties of hydrophobic DC and a high DG of the poly(PEGMA) hydrophilic functions; meanwhile, the water solubility and NP dispersion were also markedly improved. The DC-WCS-PG building block was excellently self-assembled into the core–shell nanoarchitecture. The DC-WCS-PG NPs efficiently encapsulated water-insoluble anticancer and antifungal drugs, i.e., paclitaxel (PTX) and berberine (BBR) (~360 mg/g). The DC-WCS-PG NPs met the role of controlled release with a pH-responsive function due to WCS compartments, and they showed a steady state for maintaining drugs for up to >10 days. The DC-WCS-PG NPs prolonged the inhibition capacity of BBR against the growth of S. ampelinum for 30 days. In vitro cytotoxicity results of the PTX-loaded DC-WCS-PG NPs with human breast cancer cells and human skin fibroblast cells proved the role of the DC-WCS-PG NPs as a promising nanoplatform for controlling drug release and reducing the side effects of the drugs on normal cells.

Degradation and inactivation efficacy of ozone water for antineoplastic drugs in hospital settings

PURPOSE

Occupational exposure to antineoplastic drugs in hospital settings is recognized to be hazardous, and as such environmental decontamination including degradation and inactivation of such drugs is recommended. To data, although various agents such as oxidants have been reported to be useful for decontamination, simpler, safer, and more convenient methods are required. In this study, the degradation and inactivation efficacy of ozone water, which has newly been introduced for decontamination of antineoplastic drugs in spills, was investigated for formulations of gemcitabine, irinotecan, and paclitaxel.

METHODS

Antineoplastic formulations (medicinal ingredient: ∼1.5 μmol) were mixed with 50 mL of ozone water (>4 mg/L). The reactions were monitored by high-performance liquid chromatography, and the degradation mixtures were analyzed by ¹H nuclear magnetic resonance spectroscopy in order to obtain the structural information of the degradation products. The formulations of gemcitabine and irinotecan and those degradation mixtures were evaluated for their mutagenicity using the Ames test and cytotoxicity against human cancer cells.

RESULTS

gemcitabine and irinotecan were found to be readily degraded by the ozone treatment, and their active sites were suggested to be degraded. In contrast, paclitaxel was hard to be decomposed, possibly owing to the consumption of ozone by the polyoxyethylene castor oil added as a pharmaceutical additive of the formulation. No significant mutagenic changes of Salmonella typhimurium strains used for the Ames test were observed for the samples within the concentration ranges examined. The ozone treatment showed obvious increases in cell viability for gemcitabine formulation, and mild increases for irinotecan formulation.

CONCLUSIONS

Ozone water was shown to be effective as a decomposition agent for the antineoplastic drug formulations examined, although the efficacy depends on the chemical structures of the drugs and the pharmaceutical additives. It was also suggested that ozone treatment has a tendency to decrease the toxicity of the antineoplastic drug formulations. As such, further studies are required in order to clarify the effects and application limitations of ozone water.

A simple spectrophotometric evaluation method for the hydrophobic anticancer drug paclitaxel

In this work, we demonstrate a simple spectrophotometry approach to more accurately quantify and measure paclitaxel (PTX) concentrations. PTX cannot be precisely quantified when mixed with an aqueous solvent, and carries the risk of undergoing crystal precipitation. It is likely that PTX undergoes numerous interactions with aqueous solvents and enters a supersaturated state due to its low solubility. Therefore, a quantitative method is required to measure PTX for quality control before clinical use. Although several high-performance liquid chromatography (HPLC) methods have been reported to date, not all medical facilities have a clinical laboratory with such HPLC devices and analysis techniques. Spectroscopy is a simple and convenient method; however, calibration standards are prepared with an organic solvent, such as methanol and acetonitrile, which, when mixed with PTX, can cause solvent effects that lead to inaccurate results. We generated a calibration curve of PTX at various concentrations (40%, 50%, 60%, 70%, 80%, 90% and 100%) of methanol and evaluated the relative error from HPLC results. The optimum methanol concentration for quantification of PTX was 65.8%, which corresponded to the minimum relative error. The detection limit and quantification limit were 0.030 μg/mL and 0.092 μg/mL, respectively. It was possible to predict the PTX concentration even when polyoxyethylene castor oil and anhydrous ethanol were added, as in the commercially available PTX formulation, by diluting 32-fold with saline after mixing. Our findings show that PTX can be more accurately quantified using a calibration curve when prepared in a methanol/water mixture without the need for special devices or techniques.

Determination of the Transplacental Transfer of Paclitaxel and Antipyrine by High Performance Liquid Chromatography Coupled with Photodiode Array Detector

Ex vivo placental perfusion experiments are important in understanding the quantity and mechanisms of xenobiotic transport to the fetus during pregnancy. Our study demonstrates that paclitaxel and antipyrine concentrations in placental perfusion medium containing physiological concentrations of human serum albumin during pregnancy (30 mg/mL) can be quantified by RP-HPLC and UV detection. A liquid-liquid extraction method was developed for the quantification of paclitaxel and celecoxib (internal standard) from perfusion medium. Antipyrine, which is a necessary marker in placental perfusions for determining the validity of experiments and calculating the clearance index of xenobiotics, was also analyzed by HPLC and UV detection. Antipyrine concentrations were determined by HPLC after precipitating the perfusion medium in acetonitrile and separating the precipitated proteins by centrifugation. Concentrations were fitted to linear regressions with R² values approaching 1. Lower limits of detection for paclitaxel and antipyrine were 100 ng/mL and 200 ng/mL, respectively. Both methods demonstrated high intra-day and inter-day precision and trueness. Additionally, the use of these methods was demonstrated in a placental perfusion experiment using Taxol^® (paclitaxel dissolved in Cremophor-EL). The fetal transfer rate of Taxol was 6.6% after 1 hour.

Characteristics, Properties and Analytical Methods of Paclitaxel: A Review

Paclitaxel is a diterpenoid pseudoalkaloid, isolated from Taxus brevifolia, and is largely used as an antitumoral drug. The formulation of paclitaxel known as Taxol® employs a mixture of Cremophor EL and dehydrated ethanol, due the low drug water solubility. However, Taxol® causes some unwanted side effects due to the presence of Cremophor EL and ethanol in the formulation. Based on this, there is a need for the development of drug delivery systems to enhance the solubility, permeability and stability of paclitaxel and to promote a controlled and targeted delivery for better therapeutic effect and reduced side effects. In addition, the drug has been qualitatively and quantitatively analyzed in different delivery systems. In this context, several approaches were reported focusing on the optimization of analytical methods and development of new ones, considering the need of a fast, simple, with enough sensibility and selectivity assay, which can be a problem in some analysis. This review presents a summary of methods used in quantification of paclitaxel in different matrices, such as plasma, urine, plant extract, cells and delivery systems.

Inhibitory effect of sustained perivascular delivery of paclitaxel on neointimal hyperplasia in the jugular vein after open cutdown central venous catheter placement in rats

PURPOSE

Inhibitory effect of paclitaxel on neointimal hyperplasia after open cutdown has not been elucidated.

METHODS

For the control group (n = 16), silicone 2.7-Fr catheters were placed via the right external jugular vein with the cutdown method. For the treatment group (n = 16), a mixture of 0.65 mg of paclitaxel and 1 mL of fibrin glue was infiltrated around the exposed vein after cutdown. After scheduled intervals (1, 2, 4, and 8 weeks), the vein segment was harvested and morphometric analysis was performed on cross-sections.

RESULTS

Proliferation of smooth muscle cell (SMC) was strongly suppressed in the treatment group, and the ratio of neointima to vein wall was significantly reduced in the treatment group (8 weeks; 0.63 ± 0.08 vs. 0.2 ± 0.08, P < 0.05). Luminal patency was significantly more preserved in the treatment group, and the luminal area was significantly wider in the paclitaxel-treated group compared to the control group (8 weeks; 1.91 ± 0.43 mm² vs. 5.1 ± 0.43 mm², P < 0.05). Mean SMC counts measured at 1 and 2 weeks after cutdown were significantly lower in the treatment group (2 weeks; 115 ± 22 vs. 62 ± 22). Paclitaxel was undetectable in systemic circulation (<10 ng/mL).

CONCLUSION

Sustained perivascular delivery of paclitaxel with fibrin glue was effective in inhibiting neointimal hyperplasia in rat jugular vein after open cutdown.

Quantification of taxanes in biological matrices: a review of bioanalytical assays and recommendations for development of new assays

Since the isolation of paclitaxel and its approval for the treatment of breast cancer, various taxanes and taxane formulations have been developed. To date, almost 100 bioanalytical assays have been published with the method development and optimization often extensively discussed by the authors. This Review presents an overview of assays published between January 1970 and September 2013 that described method development and validation of assays used to quantify taxanes in biological matrices such as plasma, urine, feces and tissue samples. For liquid chromatography assays, sample pretreatment, chromatographic separation and assay performance are compared. Since this Review discusses the limitations of previously developed liquid chromatography assays and gives recommendations for future assay development, it can be used as a reference for future development of liquid chromatography assays for the quantification of taxanes in various biological matrices to support preclinical and clinical studies.

Effectiveness of liposomal paclitaxel against MCF-7 breast cancer cells

Paclitaxel is an effective chemotherapeutic agent that is widely used for the treatment of several cancers, including breast, ovarian, and non-small-cell lung cancer. Due to its high lipophilicity, paclitaxel is difficult to administer and requires solubilization with Cremophor EL (polyethoxylated castor oil) and ethanol, which often lead to adverse side effects, including life-threatening anaphylaxis. Incorporation of paclitaxel in dimyristoylphosphatidylcholine:dimyristoylphosphatidylglycerol (DPPC:DMPG) liposomes can facilitate its delivery to cancer cells and eliminate the adverse reactions associated with the Cremophor EL vehicle. Accordingly, the effectiveness of liposomal paclitaxel on MCF-7 breast cancer cells was examined. The results from this study showed that (i) the lipid components of the liposomal formulation were nontoxic, (ii) the cytotoxic effects of liposomal paclitaxel were improved when compared with those seen with conventional paclitaxel, and (iii) the intracellular paclitaxel levels were higher in MCF-7 cells treated with the liposomal paclitaxel formulation. The results of these studies showed that delivery of paclitaxel as a liposomal formulation could be a promising strategy for enhancing its chemotherapeutic effects.

Targeting stents with local delivery of paclitaxel-loaded magnetic nanoparticles using uniform fields

The use of stents for vascular disease has resulted in a paradigm shift with significant improvement in therapeutic outcomes. Polymer-coated drug-eluting stents (DES) have also significantly reduced the incidence of reobstruction post stenting, a disorder termed in-stent restenosis. However, the current DESs lack the capacity for adjustment of the drug dose and release kinetics to the disease status of the treated vessel. We hypothesized that these limitations can be addressed by a strategy combining magnetic targeting via a uniform field-induced magnetization effect and a biocompatible magnetic nanoparticle (MNP) formulation designed for efficient entrapment and delivery of paclitaxel (PTX). Magnetic treatment of cultured arterial smooth muscle cells with PTX-loaded MNPs caused significant cell growth inhibition, which was not observed under nonmagnetic conditions. In agreement with the results of mathematical modeling, significantly higher localization rates of locally delivered MNPs to stented arteries were achieved with uniform-field-controlled targeting compared to nonmagnetic controls in the rat carotid stenting model. The arterial tissue levels of stent-targeted MNPs remained 4- to 10-fold higher in magnetically treated animals vs. control over 5 days post delivery. The enhanced retention of MNPs at target sites due to the uniform field-induced magnetization effect resulted in a significant inhibition of in-stent restenosis with a relatively low dose of MNP-encapsulated PTX (7.5 microg PTX/stent). Thus, this study demonstrates the feasibility of site-specific drug delivery to implanted magnetizable stents by uniform field-controlled targeting of MNPs with efficacy for in-stent restenosis.

Apple polyphenol phloretin potentiates the anticancer actions of paclitaxel through induction of apoptosis in human hep G2 cells

Phloretin (Ph), which can be obtained from apples, apple juice, and cider, is a known inhibitor of the type II glucose transporter (GLUT2). In this study, real-time PCR analysis of laser-capture microdissected (LCM) human hepatoma cells showed elevated expression (>5-fold) of GLUT2 mRNA in comparison with nonmalignant hepatocytes. In vitro and in vivo studies were performed to assess Ph antitumor activity when combined with paclitaxel (PTX) for treatment of human liver cancer cells. Inhibition of GLUT2 by Ph potentiated the anticancer effects of PTX, resensitizing human liver cancer cells to drugs. These results demonstrate that 50-150 microM Ph significantly potentiates DNA laddering induced in Hep G2 cells by 10 nM PTX. Activity assays showed that caspases 3, 8, and 9 are involved in this apoptosis. The antitumor therapeutic efficacy of Ph (10 mg/kg body weight) was determined in cells of the SCID mouse model that were treated in parallel with PTX (1 mg/kg body weight). The Hep G2-xenografted tumor volume was reduced more than fivefold in the Ph + PTX-treated mice compared to the PTX-treated group. These results suggest that Ph may be useful for cancer chemotherapy and chemoprevention.

Sensitization of ABCB1 overexpressing cells to chemotherapeutic agents by FG020326 via binding to ABCB1 and inhibiting its function

The effectiveness of chemotherapeutic treatment is usually limited by the overexpression of adenosine triphosphate binding cassette (ABC) transporters, which mediate multidrug resistance (MDR) by acting as efflux pumps to remove chemotherapeutic agents from MDR cancer cells. Thus, the inhibition of ABC transporters may represent a promising strategy to reverse MDR. This study was to characterize the actions of FG020326, a newly synthesized triaryl-substituted imidazole derivative, to reverse MDR in vitro and in vivo. FG020326 significantly potentiated the cytotoxicity of paclitaxel, doxorubicin, and vincristine in the ABCB1 (P-glycoprotein, P-gp) overexpressing cells KBv200 and MCF-7/adr, but not in the ABCB1 negative parental cell lines KB and MCF-7. However, FG020326 did not alter the cytotoxicity of the aforementioned drugs in ABCC1 (MRP1), ABCC4 (MRP4), ABCG2 (BCRP) and LRP overexpressing cell lines, KB-CV60, NIH3T3/MRP4-2, S1-M1-80 and SW1573/2R120, respectively. FG020326, following p.o. administration, was present in concentrations sufficient for reversal of MDR in mice. The co-administration of FG020326 with paclitaxel or vincristine significantly enhanced the antitumor activity of these drugs without significantly increasing toxicity in the mice bearing the KBv200 cell xenografts. In addition, FG020326, at concentrations that reversed MDR, did not significantly affect the activity of CYP3A4 or alter the pharmacokinetic profile of paclitaxel after co-administration with paclitaxel. FG020326 produced a significant concentration-dependent displacement of [3H]azidopine and inhibition of efflux of drug from cells. Furthermore, FG020326 was co-localized with ABCB1 in cell membranes. Hence, FG020326 is characterized as a third generation MDR modulator that holds great promise for the treatment of cancer patients with ABCB1-mediated MDR.