Enhanced tumor uptake, biodistribution and pharmacokinetics of etoposide loaded nanoparticles in Dalton's lymphoma tumor bearing mice

BACKGROUND

Nanotechnology plays a remarkable role in the field of the treatment of Lymphomas associated with tumor.

OBJECTIVE

The purpose of this study is to determine and to compare the tumor uptake, biodistribution and pharmacokinetics of radiolabeled etoposide and etoposide loaded nanoparticles in Dalton's Lymphoma tumor bearing mice and healthy mice.

MATERIALS AND METHODS

Etoposide loaded nanoparticles were prepared by nanoprecipitation technique using the poly (lactic-co-glycolic) acid (PLGA) in the presence of Pluronic F 68 (F 68) as a stabilizer and characterized by particle size analyzer, zeta potential and transmission electron microscope. Etoposide and etoposide loaded nanoparticles were labeled with Technetium-99m (Tc-99m) by the direct method and various quality control tests were carried out. The labeling parameters like labeling efficiency, stability, etc., were optimized to get high labeling efficiency as well as stability of the labeled formulations. Tc-99m labeled formulations were administered intravenously in Balb C mice and their biodistribution and pharmacokinetics were determined.

RESULTS

Mean size of the etoposide loaded PLGA nanoparticles was found to be 105.1 nm. The concentration of both free etoposide and nanoparticles increased with time and showed higher tumor concentrations of both free etoposide and nanoparticles increased with time and showed higher retention, indicating their applicability in effective and prolonged tumor therapy. Nuclear scintigraphic images confirm the presence of labeled complexes at the site of tumor for 24 h at higher concentration than in the normal muscles.

CONCLUSION

This study indicated higher tumor affinity and targeting properties of etoposide loaded nanoparticles than free etoposide.

Sanitation and Personal Hygiene

Sanitation is an important index of socio-economic development. Low sanitation levels lead to a host of diseases, making sanitation a key public health issue and concomitant of a clean water supply. Based on field work in two urban slums of Hyderabad, Andhra Pradesh, this article points out that sanitation implies much more than defecation issues and that it converges on several important aspects of life, such as shame and dignity and personal hygiene. Women themselves defined what is appropriate sanitation. Cleaning tasks are primarily performed by women who receive little support from men. We argue for the need to give women a central role in decision-making, designing, planning and implementation of sanitation programmes. Women’s definitions of the minimum standards of hygienic practices are clearly brought out by the study.

Spectroscopic analysis and DFT calculations of a food additive carmoisine

FT-IR and Raman techniques were employed for the vibrational characterization of the food additive Carmoisine (E122). The equilibrium geometry, various bonding features, and harmonic vibrational wavenumbers have been investigated with the help of density functional theory (DFT) calculations. A good correlation was found between the computed and experimental wavenumbers. Azo stretching wavenumbers have been lowered due to conjugation and pi-electron delocalization. Predicted electronic absorption spectra from TD-DFT calculation have been analysed comparing with the UV-vis spectrum. The first hyperpolarizability of the molecule is calculated. Intramolecular charge transfer (ICT) responsible for the optical nonlinearity of the dye molecule has been discussed theoretically and experimentally. Stability of the molecule arising from hyperconjugative interactions, charge delocalization and C-H ...O, improper, blue shifted hydrogen bonds have been analysed using natural bond orbital (NBO) analysis.

Quantum chemical computations and Fourier transform infrared spectral studies of a nonlinear food dye E110

Fourier transform infrared (FTIR) spectrum of a well-known food dye sunset yellow FCF (E110) has been recorded and analysed. Assignments of the vibrational spectrum has been facilitated by density functional theory (DFT) calculations. The results of the optimized molecular structure obtained on the basis of B3LYP with 6-31G(d) along with the 'LANL2DZ' basis sets give clear evidence for the intramolecular charge transfer (ICT) and strong hydrogen bonding enhancing the optical nonlinearity of the molecule. The first hyperpolarizability of the acidic monoazo dye 'E110' is computed. Azo stretching frequencies have been lowered due to conjugation and pi-electron delocalization. Hydroxyl vibrations with intramolecular H-bonding are analyzed, supported by the computed results. The natural bond orbitals (NBO) analysis confirms this strong hydrogen bond between the hydrogen of the hydroxyl group and nitrogen of the azo group of the molecule. Assignments of benzene and naphthalene ring vibrations are found to agree well with the theoretical wave numbers.

Development and Validation of an Ion-Pairing RP-HPLC Method for the Estimation of Gatifloxacin in Bulk and Formulations

A new, simple, and sensitive ion-pair reverse-phase liquid chromatographic method is developed and validated for the estimation of 1-cyclopropyl-6-fluoro-8-methoxy-7-(3-methylpiperazin-1-yl)-4-oxo-1,4-dihydro-quinoline-3-carboxylic acid (gatifloxacin) in bulk and formulations using a UV detector under isocratic conditions. The selected mobile phase consists of the aqueous phase (a 25 mM citrate buffer comprising of 10mM cationic and anionic pairing agents, pH adjusted to 3.5) and acetonitrile (52:48%, v/v). The selected wavelength is 292 nm. Retention time of gatifloxacin is 5.2 min. The linearity range is found to be 50 to 1000 ng/mL (the regression equation is area = 105.5 x concentration in ng/mL--695.8), and the regression coefficient is 0.9996. Validation results demonstrate accuracy, precision, and reproducibility (relative standard deviation < 3%) of the method. The detection and quantitation limits are found to be 6.50 and 17.38 ng/mL, respectively. The method is successfully used for the estimation of gatifloxacin in a variety of dosage forms, and the results are in good agreement with the label claims.

New, sensitive and validated spectrofluorimetric method for the estimation of etoposide in bulk and pharmaceutical formulations

A new, simple and sensitive spectrofluorimetric method was developed for the routine estimation of etoposide, an anticancer drug, in bulk and in pharmaceutical formulations. The medium selected for the estimation of etoposide was methanol : phosphate buffer (pH 7.4) in a ratio of 70 : 30 v/v. Excitation and emission wavelengths used were 240 and 324 nm respectively. The method was validated according to ICH and U.S.P guidelines. Linearity range was 200-1000 ng/ml with detection and quantitation limits of 23 ng/ml and 72 ng/ml respectively. Regression equation obtained was Fluorescence Intensity = 6.704 (Concentration in ng/ml) + 115.4. The drug was found to be stable and there was no interference from the excipients present in different formulations of etoposide.