Abstract 1687: Vandetanib as a potential new treatment for ER negative breast cancers

A Novel Green Micellar HPLC-UV Method for the Estimation of Vandetanib in Pure Form, Human Urine, Human Plasma and Human Liver Microsomes Matrices with Application to Metabolic Stability Evaluation

Vandetanib (Caprelsa^®; VNB) is a prescription medicine that is used for the treatment of medullary thyroid cancer that has disrupted other body parts or that cannot be removed by surgery. It is considered a tyrosine kinase inhibitor (TKI). Fast, sensitive and validated HPLC-UV was established for VNB quantification in pure human biological fluids (urine and plasma) and human liver microsomes (HLMs). This analytical methodology was applied also to the metabolic stability assessment of VNB. This method was performed using a phenyl column (250 mm × 4.6 mm id, 5 µm particle size). A sodium dodecyl sulphate solution (0.05 M, pH 3.0 using 0.02 M orthophosphoric acid) containing 0.3% triethylamine and 10% n-butanol was used as a mobile phase and was pumped isocratically at a flow rate of 0.7 mL/min and at a 260 nm detection wavelength. The total elution time was 6 min with an injection volume of 20 μL. The linearity of the established methodology ranged from 30 to 500 ng/mL in pure form and 50 to 500 ng/mL (r² ≥ 0.9994) in human biological fluids and HLMs. No significant interference from the matrix components was observed. The proposed methodology revealed the benefits of being green, reliable and economic.

Simple and efficient spectroscopic-based univariate sequential methods for simultaneous quantitative analysis of vandetanib, dasatinib, and sorafenib in pharmaceutical preparations and biological fluids

Six sequential spectrophotometric-based univariate methods were developed and validated for the simultaneous estimation of three novel anticancer drugs vandetanib (VAN), dasatinib (DAS), and sorafenib (SOR) in a mixture, without the requirement for separation. These methods are novel, simple, precise, and accurate. Different steps including zero crossing, ratio-based, and/or derivative spectra were utilized to develop these analytical methods, namely, ratio difference spectrophotometric method, constant center method, successive derivative ratio method, isoabsorptive method, mean centering of the ratio spectra method, and derivative ratio spectrum-zero crossing method. The calibration curve linearity was ranged from 2 to 9, 2-9, and 3-9 μgmL^-1 for VAN, DAS, and SOR, respectively. These established methods were applied for the quantification of the three selected drugs in different biological fluids (spiked human plasma and urine) and pharmaceutical preparations. The aforementioned methods were established for the concurrent estimation of ternary and binary mixtures to enhance the signal-to-noise ratio. The results did not statistically differ from the other reported methods, indicating no significant difference in accuracy and precision at p = 0.05.

Development of novel response surface methodology-assisted micellar enhanced synchronous spectrofluorimetric method for determination of vandetanib in tablets, human plasma and urine

A highly sensitive and accurate novel response surface methodology (RSM)-assisted micellar enhanced synchronous spectrofluorimetric method was developed and validated for determination of vandetanib (VDB) in tablets, human plasma and urine. The method relied on enhancement of the fluorescence behavior of VDB in polyoxyethylene hydrogenated castor oil 40 (HCO 40) micellar medium and measuring the fluorescence using synchronous scan approach (Δλ = 50 nm). Key factors affecting VDB fluorescence were optimized by RSM using Box-Behnken design. These factors were the type and volume of surfactant and pH of the buffer medium. Under the optimum conditions, the fluorescence-concentration plot was linear over the range 40-600 ng mL^-1; the limits of detection and quantification were 5.22 and 15.82 ng mL^-1, respectively. The suggested method was successfully applied to the analysis of laboratory-prepared tablets, spiked human plasma and urine samples. The results were statistically compared with those acquired by a pre-validated liquid chromatography-tandem mass spectrometric reference method and the results obtained from both methods were found to be in good agreement.

Repositioning "old" drugs for new causes: identifying new inhibitors of prostate cancer cell migration and invasion

The majority of prostate cancer (PCa) deaths occur due to the metastatic spread of tumor cells to distant organs. Currently, there is a lack of effective therapies once tumor cells have spread outside the prostate. It is therefore imperative to rapidly develop therapeutics to inhibit the metastatic spread of tumor cells. Gain of cell motility and invasive properties is the first step of metastasis and by inhibiting motility one can potentially inhibit metastasis. Using the drug repositioning strategy, we developed a cell-based multi-parameter primary screening assay to identify drugs that inhibit the migratory and invasive properties of metastatic PC-3 PCa cells. Following the completion of the primary screening assay, 33 drugs were identified from an FDA approved drug library that either inhibited migration or were cytotoxic to the PC-3 cells. Based on the data obtained from the subsequent validation studies, mitoxantrone hydrochloride, simvastatin, fluvastatin and vandetanib were identified as strong candidates that can inhibit both the migration and invasion of PC-3 cells without significantly affecting cell viability. By employing the drug repositioning strategy instead of a de novo drug discovery and development strategy, the identified drug candidates have the potential to be rapidly translated into the clinic for the management of men with aggressive forms of PCa.