Development and validation of a HPLC method for the determination of benzo(a)pyrene in human breast milk.

A simple analytical procedure was developed for the quantitation of benzo(a)pyrene in human breast milk using solid phase extraction (SPE) combined with high performance liquid chromatography. Before the chromatographic process, SPE, including C18 functional groups in silicagel cartridges, was conducted for sample preparation. A C18 column (100×4.6 mm id, 3 µm particle size) was used with acetonitrile:water (80:20) as the mobile phase at a flow rate 1mL/min at 30°C. Fluorimetric detection was performed for excitation and emission at 290 and 406 nm, respectively. It was observed that the calibration curve was linear over the range of 0.5-80 ng/mL. The limit of detection and limit of quantitation were found to be 0.5 and 1.07 ng/mL, respectively. Intraday and interday relative standard deviation values were less than 5.15%. Moreover, the newly developed method provides a fast, simple, cost effective, and sensitive assay to detect an important carcinogen substance, benzo(a)pyrene, in human breast milk.

Current HPLC Methods for Assay of Nano Drug Delivery Systems.

In nano drug formulations the mechanism of release is a critical process to recognize controlled and targeted drug delivery systems. In order to gain high bioavailability and specificity from the drug to reach its therapeutic goal, the active substance must be loaded into the nanoparticles efficiently. Therefore, the amount in biological fluids or tissues and the remaining amount in nano carriers are very important parameters to understand the potential of the nano drug delivery systems. For this aim, suitable and validated quantitation methods are required to determine released drug concentrations from nano pharmaceutical formulations. HPLC (High Performance Liquid Chromatography) is one of the most common techniques used for determination of released drug content out of nano drug formulations, in different physical conditions, over different periods of time. Since there are many types of HPLC methods depending on detector and column types, it is a challenge for the researchers to choose a suitable method that is simple, fast and validated HPLC techniques for their nano drug delivery systems. This review's goal is to compare HPLC methods that are currently used in different nano drug delivery systems in order to provide detailed and useful information for researchers.

Spectrofluorimetric determination of tobramycin in human serum and pharmaceutical preparations by derivatization with fluorescamine.

A simple, sensitive and selective spectrofluorimetric method has been developed for the determination of tobramycin (TOB) in human serum and pharmaceutical preparations. The method is based on the reaction between the primary amino group of TOB and fluorescamine in borate buffer, pH 8.5, to give a highly fluorescent derivative which is measured at 469 nm after excitation at 388 nm. The fluorescence intensity was directly proportional to the concentration over the range 300-1500 ng/mL, with a limit of detection of 65 ng/mL and limit of quantitation of 215 ng/mL. All variables were investigated to optimize the reaction conditions. The method was validated according to International Conference on Harmonization guidelines in terms of specificity, linearity, limit of detection, limit of quantification, accuracy, precision and robustness. Good recoveries were obtained ranging from 97.4 to 100.64%, indicating that no interference was observed from concomitants usually present in pharmaceutical dosage forms. The method was successfully, applied for the analysis of the drug substance in its pharmaceutical preparations and spiked serum samples.

A new HPLC method with fluorescence detection for the determination of memantine in human plasma.

A sensitive and selective HPLC method with fluorometric detection was developed for the determination of memantine in human plasma and applied to a pharmacokinetic study. Memantine was precolumn derivatized with 9-fluorenylmethyl chloroformate, and the fluorescent derivative was separated on an RP C18 column using a mobile phase composed of acetonitrile-10 mM orthophosphoric acid containing 1 mL/L triethylamine with gradient elution. The method was based on the measurement of the derivative using fluorescence detection at 310 nm with excitation at 260 nm. The calibration curve was linear over the range 1.0-50.0 ng/mL. LOD and LOQ were found to be 0.3 and 1.0 ng/mL, respectively. Intraday and interday RSD values were less than 3.39%.

A review of the liquid chromatographic methods for the determination of biogenic amines in foods.

Biogenic amines (BAs) are biologically active molecules which have aliphatic (putrescine, cadaverine, spermine, spermidine), aromatic (tyramine, phenylethylamine) or heterocyclic (histamine, tryptamine) structures. They can be detected in raw and processed foods which are formed and degraded through several pathways during the metabolic processes of animals, plants and microorganisms. The identification and quantitation procedures of BAs in food samples are very important, because BAs are considered as the indicators of food quality and freshness. The determination of BAs are commonly achieved by separation techniques such as high-performance liquid chromatography (HPLC), gas chromatography (GC) and capillary electrophoresis (CE). In this article, analysis of BAs in foods were reviewed from 2007 to present.