Farzad Kobarfard

Biodistribution of amikacin solid lipid nanoparticles after pulmonary delivery.

The main purpose of the present work was studying the biodistribution of amikacin solid lipid nanoparticles (SLNs) after pulmonary delivery to increase its concentration in the lungs for treatment of cystic fibrosis lung infections and also providing a new method for clinical application of amikacin. To achieve this aim, 99mTc labelled amikacin was loaded in cholesterol SLNs and after in vitro optimization, the desired SLNs and free drug were administered through pulmonary and i.v. routes to male rats and qualitative and biodistribution studies were done. Results showed that pulmonary delivery of SLNs of amikacin by microsprayer caused higher drug concentration in lungs than kidneys while i.v. administration of free drug caused reverse conditions. It seems that pulmonary delivery of SLNs may improve patients compliance due to reduction of drug side effects in kidneys and elongation of drug dosing intervals due to the sustained drug release from SLNs.

Involvement of mitochondrial/lysosomal toxic cross-talk in ecstasy induced liver toxicity under hyperthermic condition.

The initial objectives of this study were to evaluate the extent of 3, 4-methylenedioxymethamphetamine (MDMA) induced loss of cell viability (cytotoxicity), induction of reactive oxygen species formation and damage to sub-cellular organelles (e.g. mitochondria/lysosomes) in freshly isolated rat hepatocytes under normothermic conditions (37 degrees C) and to compare the results with the effects obtained under hyperthermic conditions (41 degrees C). MDMA induced cytotoxicity, reactive oxygen species formation, mitochondrial membrane potential decline and lysosomal membrane leakiness in isolated rat hepatocytes at 37 degrees C. A rise in incubation temperature from 37 degrees C to 41 degrees C had an additive/synergic effect on the oxidative stress markers. We observed variations in mitochondrial membrane potential and lysosomal membrane stability that are significantly (P<0.05) higher than those under normothermic conditions. Antioxidants, reactive oxygen species scavengers, lysosomal inactivators, mitochondrial permeability transition (MPT) pore sealing agents, NADPH P450 reductase inhibitor, and inhibitors of reduced CYP2E1 and CYP2D6 prevented all MDMA induced hepatocyte oxidative stress cytotoxicity markers. It is therefore suggested that metabolic reductive activation of MDMA by reduced cytochrome P450s and glutathione could lead to generation of some biological reactive intermediates which could activate reactive oxygen species generation and cause mitochondrial and lysosomal oxidative stress membrane damages. We finally concluded that hyperthermia could potentiate MDMA induced liver toxicity probably through a mitochondrial/lysosomal toxic cross-talk in freshly isolated rat hepatocytes.

Quantification of endogenous steroids in human urine by gas chromatography mass spectrometry using a surrogate analyte approach.

Providing real blank sample is a problem in determination of endogenous steroids in complex matrices. A new quantification strategy is proposed in the present study, which is based on using isotope-labeled steroids instead of natural steroids for constructing calibration line. This approach is called surrogate analyte and it is shown that its accuracy is better than some of the previously described methods at low concentrations and comparable to standard addition method at medium and high concentration levels. The method was fully validated to satisfy the ICH criteria and it was applied for determination of endogenous steroids in several urine samples.

Determination of impurities in illicit methamphetamine samples seized in Iran

In this study fifty samples of crystalline methamphetamine obtained from antinarcotics police of Iran seized during the year 2010 were analyzed. In order to determine the chemical characteristics of these samples, anion test, Gas Chromatography-Mass Spectrometry (GC-MS) and Liquid Chromatography-Mass Spectrometry (LC-MS) were carried out on the samples. All of the samples containing methamphetamine tested positive for chloride anion. The range of methamphetamine hydrochloride content in these samples was 33-95%. One sample out of 50 contained no methamphetamine. The fact that 1,2-dimethyl-3-phenylaziridine was the most frequently found impurity in the analyzed samples, indicates that most of the methamphetamine samples seized in Iran have been synthesized from pseudoephedrine as starting material.

A new approach on methamphetamine-induced hepatotoxicity: involvement of mitochondrial dysfunction

Abstract 1.u2002Methamphetamine (METH) is a highly addictive stimulant that is among the most widely abused illicit drugs. Clinical evidence has shown that the liver is a target of METH toxicity. The exact cellular and molecular mechanisms involved in METH-induced hepatotoxicity have not yet been completely understood. 2.u2002In this study, the cellular pathways involved in METH liver toxicity were investigated in freshly isolated rat hepatocytes. METH cytotoxicity was associated with reactive oxygen species (ROS) formation, lipid peroxidation and rapid glutathione (GSH) depletion which is a third marker of cellular oxidative stress. Our results showed that the hepatocyte mitochondrial membrane potential (ΔΨm) was rapidly decreased by METH, which was prevented by antioxidants and ROS scavenger, suggesting that mitochondrial membrane damage was a consequence of ROS formation. Incubation of hepatocytes with METH also caused release of cytochrome c from mitochondria into the cytosol before cell lysis ensued. 3.u2002Our findings showed that cytotoxic action of METH is mediated by oxidative stress and subsequent changes in mitochondrial membrane conformation and cytochrome c release into the cytosol which causes mitochondrial collapse of ΔΨm.

Isoniazid, rifampicin and pyrazinamide plasma concentrations 2 and 6 h post dose in patients with pulmonary tuberculosis.

BACKGROUNDnLow concentrations of anti-tuberculosis drugs are related to drug resistance and treatment failure.nnnOBJECTIVEnTo determine the prevalence of low plasma concentrations of anti-tuberculosis drugs.nnnMETHODSnThe study was performed among 60 pulmonary tuberculosis (TB) in-patients at a tertiary care university-affiliated hospital in Tehran, Iran. Drug samples were drawn 2 and 6 h post dose for isoniazid (INH), rifampicin (RMP) and pyrazinamide (PZA); related concentrations were determined using high-performance liquid chromatography. Plasma drug concentrations, duration of treatment, age, sex, liver enzyme levels, administered doses and smoking status were evaluated and recorded.nnnRESULTSnAmong 60 patients recruited to the study, the mean (±SD) age was 54.2 (±20.9) years; 39 were female. The median peak plasma concentrations (C(max)) of INH, RMP and PZA were respectively 2.5, 4.0 and 43.6 μg/ml; 81% of the patients had drug plasma concentrations lower than the target ranges for at least one administered drug. Respectively 49.1%, 92.5% and 8.7% of the patients had low concentrations of INH, RMP and PZA.nnnCONCLUSIONnThe results indicate that RMP concentrations are below the reference range in most patients, while PZA is within the target range of the standard doses.

Optimization of freeze-drying condition of amikacin solid lipid nanoparticles using D-optimal experimental design

Amikacin as an aminoglycoside antibiotic was chosen to be loaded in a cholesterol carrier with nanoparticle size and sustained release profile to increase the dose interval of amikacin and reduce side-effects. To support the stability of solid lipid nanoparticles (SLNs), freeze-drying was suggested. Factors affecting the freeze-drying process in the present study included the type and concentration of cryoprotectants. Pre-freezing temperature effects were also studied on particle size of SLNs of amikacin. In some preliminary experiments, important factors which influenced the particle size of SLNs after lyophilization were selected and a D-optimal design was applied to optimize the freeze-drying conditions in the production of SLNs with minimum particle size growth after freeze-drying. Zeta potential, DSC thermograms, release profiles and morphology of the optimized particles were studied before and after freeze-drying. Results showed sucrose changed the particle size of SLNs of amikacin from 149u2009±u20094u2009nm to 23.9u2009±u200916.7u2009nm; in that situation, the absolute value of zeta potential changed from 1u2009±u20090.7 mV to 13u2009±u20094 mV. The release profiles showed a sustained release behavior of the loaded drug that did not change significantly before and after freeze-drying, but a burst effect was seen after it in the first 2u2009h. DSC analysis showed chemical interaction between amikacin and cholesterol.

A validated dispersive liquid-liquid microextraction method for extraction of ochratoxin A from raisin samples.

A method based on dispersive liquid-liquid microextraction (DLLME) was developed for the quantitative extraction of Ochratoxin A (OTA) from raisin samples. The influence of various parameters on the recovery of OTA such as type and volume of DLLME extractant, centrifuging and sonication time, also volume of deionized water was investigated. Recovery values under the optimum conditions were between 68.6 and 85.2xa0%, the inner and intra-day precision expressed as relative standard deviation (RSD%, nu2009=u20093), were less than 15xa0% at spiking levels of 2.5–30xa0μgxa0kg−1. Linearity was studied from 0.5 to 30xa0μgxa0L−1, and the limits of detection (LOD) and quantification (LOQ) were 0.7 and 2.0xa0μgxa0kg−1, respectively. Real samples were analyzed by DLLME method and compared with confirmative immunoaffinity Column Chromatography (IAC) clean-up. Low cost, simplicity of operation, speed and minimum consumption of organic solvent were the main advantages of proposed method. The mean contamination of samples was 0.88xa0μgxa0kg−1 that was lower than European Legal Limit.

Occurrence of melamine contamination in powder and liquid milk in market of Iran

Melamine contamination is known as a significant health risk and seriously considered by scientists worldwide. Cyanuric acid is one of the melamine by-products that contribute to its renal toxicity via the formation of melamine cyanurate crystals in the kidney. Therefore, co-determination of melamine and cyanuric acid in both powder and liquid milk samples has grown significantly throughout the world. High-performance LC with ultraviolet detection has been used as a simple and rapid method for the determination of melamine and cyanuric acid in powder and liquid milk samples and the results confirmed by using LC-MS/MS. In this study, nine powder milk and five liquid milk samples from different brands available in Iranian markets were chosen randomly and analysed. SPE column was used to clean up the samples. The results showed that except one brand of milk powder and liquid milk, all other samples were contaminated with melamine in the range of 1.50–30.32u2009μg/g for milk powder and 0.11–1.48u2009μg/mL for liquid milk. No cyanuric acid was detected in milk powder or liquid milk samples, which reduces the risk of melamine toxicity for consumers.

Unusual ingenoids from Euphorbia erythradenia Bioss. with pro-apoptotic effects

Dichloromethane-acetone extract of Euphorbia erythradenia Bioss., a spurge endemic to the Iran, afforded four novel tetrahydroingenol diterpenes, one new myrsinane type diterpene, and two known triterpenes. Tetrahydroingenoids are novel compounds not only for the double bond reduction but also for their unique hydroxylation pattern at C-11 and C-13. The structures of these compounds were elucidated by spectroscopic methods, and especially 2D NMR measurements. The biological effects of the compounds were done by the MTT and Annexin V-FITC & PI staining assays on different cancer cell lines. The results obtained on EJ-138, CAOV-4, and OVCAR-3 cell lines suggested that tetrahydroingenanes inhibit cell proliferation through apoptosis in cancer cell lines. In conclusion, the new pattern of hydrogenation and hydroxylation of these compounds compared to other ingenoids, along with their apoptosis inducing properties on cancer cells, makes them of great interest for more investigation.