فهرست مطالب effat souri

In this study entacapone, levodopa, and carbidopa, were determined with high precision in the presence of each other. UV-VIS spectroscopy was used as an easy and low-cost technique for the analysis and the derivative spectrophotometric method was applied for elimination of absorption interferences. For this purpose, the derivative spectra of each compound were studied separately, and zero crossing points were determined for each of them. The zero-crossing points in which the absorption was observed only for one compound were found and evaluated for quantitative analysis. Calibration curves were drawn from the second and third derivative signals for each compound and the linear range was determined. The method was linear in the range of 1-5 µg/mL for levodopa, 0.25-1.7 µg/mL for carbidopa, and 2-14 µg/mL for entacapone. The accuracy and precision of the proposed method were evaluated by within-day and between-day tests (CV < 1.56% and error < 1.7%) and finally, these drugs were determined in pharmaceutical dosage forms by the developed method.

Pistacia vera fruit is a popular nut belonging to Anacardiaceae family. Traditionally, the hulls have been used as herbal remedies for treatment of oral and skin wounds,peptic ulcers and hemorrhoids. In this study, anacardic acid (13:0) was elucidated by EI-MS, FTIR, 1D-NMR and 2D-NMR data analysisfrom active fraction. Cytotoxic activity was assessed against normal NIH/3T3 cells, and several cancerous human cells, including human breast cancer (MCF-7), hepatocarcinoma (HepG-2) and gastric cancer (MKN-45) using MTT assay. The wound healing activity of this compound was evaluated using in vitro scratch-wound healing assay on NIH/3T3 cells. Anacardic acid (13:0) was toxic at the concentrations tested against all cell lines (6.25-100 µg/mL). Theselectivity index showed no selective cytotoxicity (SI< 2); however, anacardic acid (13:0) revealed significant wound healing effects through the migration of NIH/3T3 cells at the concentrations of 1.25-5 µg/mL. These results suggested that anacardic acid (13:0) from P. verahull has cytotoxic activity on human cancer cell lines and can also be useful as a bioactive molecule in wounds treatment. However, more in vitro and in vivo studies need to be done to confirm the efficacy and cytotoxicity of anacardicacid (13:0).

The present study produces a new, accurate, and simple spectrofluorimetric technique for the determination of pregabalin after derivatization with 9-fluorenylmethyl chloroformate in mild basic medium. Pregabalin, containing a primary amine group, reacts with 9-fluorenylmethyl chloroformate, a fluorophore reagent, in borate buffer and produces a fluorescent derivative. The maximum fluorescence intensity of the derivative and reagent was obtained at 315 nm after excitation at 280 nm. The fluorescence intensity of the reagent increases after derivatization with pregabalin, and the difference in the fluorescence intensity is proportional to the concentration of pregabalin. Experimental parameters which affect the derivatization reaction were studied. The best derivatization reaction between pregabalin and 9-fluorenylmethyl chloroformate was obtained after 30 sec. when 40 µg mL-1 of the reagent was used in a borate buffer of pH 9.0. Under optimized conditions, the linearity range (6-150 µg mL-1) of the method with a correlation coefficient of r2 0.9998, accuracy (Error<1.7%), and precision (CV<2.0%) was acceptable. The validated method was utilized for quantifying pregabalin in dosage form without interferences and showed good agreement with a reference method. 

Mometasone furoate is a synthetic glucocorticoid with anti-inflammatory and anti-allergic effects, used for the treatment of allergic rhinitis, asthma, and dermatoses. In this study, a spectrophotometric method, as a selective and sensitive method, was developed for the determination of mometasone furoate after derivatization. For this purpose, mometasone was first reacted with sodium cyanide to prepare the drug derivatives. After that, the effects of different variables such as reaction solvent, concentration of the reagents, pH, and reaction time were studied. The final results showed that the determination method was linear in the range of 2-18 μg/ml. It seems that after 24 hours, the reaction was complete. The reaction product was characterized by NMR and FT-IR spectroscopy, and the accuracy and precision of the developed method were also studied. At last, the method was checked on Mometasone Ointment (0.1%), and the results were compared with the results of the HPLC method as a standard method.

In this research, a reversed phase high performance liquid chromatographic method was developed for the simultaneous determination of two tyrosine kinase inhibitors, nilotinib and sorafenib. Separation was performed on an Agilent C18 column (4.6×250 mm, 5µm) with mobile phase composition of potassium dihydrogen phosphate buffer (25 mM, pH 4.2) and acetonitrile (35:65 v/v) at 1.2 mL/min with UV detection at 265 nm. Specificity, linearity, precision, accuracy, and robustness of the proposed method were all assessed. Nilotinib and sorafenib had estimated retention times of 5.1 and 5.9 minutes, respectively. Linear concentration ranges for nilotinib and sorafenib, were determined as 0.05-1 µg/mL and 10-45 µg/mL with comparable coefficient correlations (0.999). For nilotinib and sorafenib, the limits of detection (LOD) were determined as 0.030 and 0.020 µg/mL, while the limits of quantification (LOQ) were 0.101 and 0.069 µg/mL respectively.

Three rapid spectrophotometric methods were developed for the determination of sunitinib based on the formation of ion-pair complex in acidic medium with bromocresol purple, bromothymol blue, and bromophenol blue. The formed ion-pair complexes, extractable with chloroform, were measured at 422 nm for bromocresol purple, 425 nm for bromothymol blue and 427 nm for bromophenol blue. All these methods were optimized for the pH of buffer and the volume of the reagent. The methods were linear over the range of 1-200 µg/mL for bromocresol purple, 1-150 µg/mL for bromothymol blue, and 2-200 µg/mL for bromophenol blue with a very low limit of quantification and acceptable accuracy and precision. Using the proposed methods for determination of sunitinib in pharmaceutical dosage forms showed reliable results comparable to previously published method.

A simple, sensitive, and non-extractive spectrophotometric method was developed for the determination of copper (II) using a newly synthesized chromogenic reagent, 6-(phenanthrene-3-yl)-1,2,4,-triazine-3-thione(PhDTT), in Tween 80 neutral surfactant. To synthesize the reagent (PhDDT), amyl nitrite was added to 3-acethylphenanthrene and refluxed for 26 hours to produce 2-oxo-2-(phenanthren-3-yl) acetaldehyde oxime (I). The reaction of compound (I) with thiosemicarbazide yielded the reagent (PhDDT). Copper (II) forms a red colored complex with 6-(phenanthrene-3-yl)-1,2,4,-triazine-3-tion which shows maximum absorbance at 460 nm in the pH range 9.0-11.0. Beer’s law was obeyed over the concentration range of 1.4-10 µg/mL Cu2+ with r2 = 0.999.  The limit of detection was 0.48 μg/mL of copper (II). The within-day and between-day precision values were in the range of 0.38-3.3%. The method was tested by analyzing the amalgam samples. The results were in good agreement with the atomic absorption.

We evaluated the anti-malarial activity of Heracleum persicum individually and in combination with chloroquine.
This study was conducted at the School of Public Health, Tehran University of Medical Sciences, Tehran, Iran in 2015-2016. The Peter̛ s method was used for determining fifty percent effective dose (ED50) of the H. persicum extract and chloroquine individually against chloroquine sensitive P. berghei in small white mice. Six experimental groups for H. persicum and 6 groups for chloroquine and two control group (positive and negative) were considered for determination of ED50. Interaction between H. persicum and chloroquine also was evaluated based on fixed ratios method. Ratios of 0/100, 20/80, 40/60, 60/40, 80/20, 100/0 of ED50 of chloroquine and H. persicum respectively were tested against the parasite. Then inhibitory effects of two drugs were calculated and plotted in the relevant graphs.
Overall, 1500 mg/kg, and 1000 mg/kg concentrations of H. persicum against P. berghei resulted in ED50 and ED74 respectively. ED50 of chloroquine against the parasite was obtained as 1.4 mg/kg of mouse body weight. Moreover, combination of H. persicum and chloroquine showed a weak potentiation in ratios of 40/60 (chloroquine . persicum) with 64% inhibition, but not in other ratios.
Although H. persicum individually showed a reasonable antimalarial efficacy against chloroquine sensitive P. berghei, in combination with chloroquine it showed additive or antagonism result except in ratios of 40%CQ%HP.

Buprenorphine is a partial mu agonist and kappa antagonist which is used for the treatment of pain and opioid addiction. A mixture of buprenorphine hydrochloride and naloxone hydrochloride has been approved for the treatment of opioid dependence.
In this study a third order derivative spectrophotometric method based on zero-crossing technique has been used for the simultaneous determination of buprenorphine hydrochloride and naloxone hydrochloride in tablets. The measurements were carried out at wavelengths of 257.8 (zero-crossing point of naloxone hydrochloride) and 252.2 nm (zero-crossing point of buprenorphice hydrochloride) for buprenorphine hydrochloride and naloxone hydrochloride, respectively in the third order derivative spectra obtained in methanol and 0.1 M NaOH (50:50) as solvent. The method was found to be linear in the range of 20-80 µg/mL for buprenorphine hydrochloride and 5-20 µg/mL for naloxone hydrochloride. The within-day and between-day coefficient of variation and error values were less than 2.5% and 1.8%, respectively. The proposed method was successfully used for simultaneous determination of these drugs in pharmaceutical dosage form without any interference from excipients or need to prior separation before analysis.

Combination dosage forms of naproxen sodium and pseudoephedrine hydrochloride are used for symptomatic treatment of cold and sinus disorders. In this study, fourth-order derivative spectrophotometric method was used for simultaneous determination of naproxen sodium and pseudoephedrine hydrochloride. The method was linear over the range of 2-28 μg/ml for pseudoephedrine hydrochloride and 4 200 μg/ml for naproxen sodium. The within-day and between-day coefficient of variation values were less than 5.8% and 2.5% for pseudoephedrine hydrochloride and naproxen sodium, respectively. The application of the proposed method for simultaneous determination of naproxen and pseudoephedrine in dosage forms was demonstrated without any special pretreatment.

Fluvoxamine maleate is a selective serotonin reuptake inhibitor, which is used for the treatment of different types of depressive disorders. In the present study, a stability indicating HPLC method was developed and validated for the determination of fluvoxamine maleate. The chromatographic separation was carried out using a Nova-Pak CN column and a mixture of K2HPO4 50 mM (pH 7.0) and acetonitrile (60: 40, v/v) as the mobile phase. Target compounds were detected using a UV detector set at 235 nm. The developed method was linear over the concentration range of 1-80 μg/ml with acceptable precision (CV values < 2.0%) and accuracy (error values < 1.6%). The degradation studies showed that fluvoxamine maleate is relatively unstable under acidic, basic and oxidative conditions and also when exposed to UV radiation. On the other hand, the bulk powder of fluvoxamine maleate was relatively stable when exposed to visible light or heat. The proposed method was successfully applied for the determination of active ingredient of fluvoxamine dosage form without any interference from tablet excipients.

A mixture of acetaminophen, diphenhydramine hydrochloride and pseudoephedrine hydrochloride is used for the symptomatic treatment of common cold. In this study, a derivative spectrophotometric method based on zero-crossing technique was proposed for simultaneous determination of acetaminophen, diphenhydramine hydrochloride and pseudoephedrine hydrochloride. Determination of these drugs was performed using the 1D value of acetaminophen at 281.5 nm, 2D value of diphenhydramine hydrochloride at 226.0 nm and 4D value of pseudoephedrine hydrochloride at 218.0 nm. The analysis method was linear over the range of 5-50, 0.25-4, and 0.5-5 μg/mL for acetaminophen, diphenhydramine hydrochloride and pseudoephedrine hydrochloride, respectively. The within-day and between-day CV and error values for all three compounds were within an acceptable range (CV.

In this study a sensitive, simple and accurate spectrophotometric method was suggested for determination of tamsulosin in bulk powder and pharmaceutical dosage form based on the formation of an ion-pair complex between the drug and bromocresol green in a buffer solution at pH 3.5. The formed yellow color complex was extracted with chloroform and measured at 415 nm. The optimum reaction conditions such as pH, reagent amount, extracting solvent and the stoichiometry of the ion-pair complex were investigated. Under the optimized conditions, the Beer''s law was obeyed in the concentration range of 1-160 mg/mL with acceptable correlation coefficient (r2 > 0.9997) and precision (CV < 3%) and accuracy (error < 2%). The proposed method was successfully used for the determination of tamsulosin in pharmaceutical capsule with no-significant interferences of excipients.

Drug resistance in malaria parasites is extending in the world particularly in chemical synthesized drugs such as 4- aminoquinolines and aminoalcoholes. Employing herbal extracts is encouraged by WHO in the malarious areas. In this study, the effectiveness of ethanolic extract of Artemisia aucheri individually and in combination with chloro­quine, has been considered against chloroquine - sensitive strain of Plasmodium berghei. At the first stage, ED50 of A. aucheri and chloroquine on P. berghei was calculated using in vivo test. Then based on the ED50s combination of A. aucheri and chloroquine with ratios of 0/100,10/90,20/80,30/70,40/60,50 /50,60/40,70/30,80/20,90/10 and100/0 were tested against the parasite. For evaluat­ing the adverse effect of A. aucheri on the mice, for two weeks 1000mg/kg of the extract was daily employed and the mice were followed up for fifty days ED50s for chloroquine and A. aucheri were 1.6mg/kg and 1000mg/kg respectively. The outcome of two drugs combination on the mice showed antagonistic effects on the chloroquine – sensitive strain of parasite. Two weeks daily administration of A. aucheri had no toxic effect on the mice. A. aucheri individually can be effective in reducing the parasite while in combination with chloroquine loses its property.

A stability indicating High-Performance Liquid Chromatography (HPLC) method was validated and used to study the degradation of cetirizine dihydrochloride in acidic and oxidative conditions. The separation was carried out on a Symmetry C18 column and a mixture of 50 mM KH2PO4 and acetonitrile (60:40 v/v, pH = 3.5) was used as the mobile phase. The method was linear over the range of 1-20 μg/mL of cetirizine dihydrochloride (r2 > 0.999) and the withinday and between-day precision values were less than 1.5%. The results showed that cetirizine dihydrochloride was unstable in 2 M HCl and 0.5% H2O2. The kinetics of the acidic degradation showed a pseudo-first-order reaction in the temperature range of 70-90°C. In addition, the kinetics of hydrogen peroxide mediated degradation was pseudo-first-order in the temperature range of 50-80°C.

Malaria is one of the worldwide parasitic diseases which threaten the life of hundreds of millions of people at the malarious areas each year. The emergence of chloroquine-resistant strains of Plasmodium falciparum in most of the malarious areas has encountered the relevant countries with some difficulties about treating the acute cases of the disease particulary if the monotherapy regimen has been used. Because of many advantages for the combination therapy, the effectiveness of chloroquine (CQ) and Otostegia persica (OP), a medicinal plant in combination form, was tested against the chloroquine-sensitive and chloroquine-resistant strains of Plasmodium berghei in sourian mouse using in-vivo adapted fixed ratios method in this study. At the first step, ED50s (50% effective dose) of chloroquine and O. persica against both CQ-sensitive and CQ-resistant strains of P. berghei were calculated using in-vivo test in the mice. Ratios of 0, 10, 30, 50, 70, 90 and100% from each ED50 were prepared and contrarily combined together to make the following fixed ratios of 0/100, 10/90, 30/70, 50/50, 70/30, 90/10, and 100/0 of CQ/OP and the parasites were exposed to the combined ratios. Determination of ED50s showed 1.1 mg/Kg and 2.4 mg/Kg of mouse body weight for chloroquine in CQ-sensitive and CQ-resistant strains respectively and 450 mg/Kg for O. persica in both strains. The results also showed that the combinations of “50% CQ + 50% OP”, “30% CQ + 70% O.P” and “70% CQ + 30% OP” were more effective than other combinations against CQ-sensitive strain. The fixed ratio combinations of chloroquine and O. persica showed an additive in CQ-resistant strain. Toxicity consideration showed no toxic effect of the combinations on the mice. Otostegia persica potentiated the effectiveness of chloroquine against the chloroquine-sensitive strain of P. berghei but not on chloroquine-resistant P. berghei. Moreover, the greatly modified fixed ratios method in this study can be considered as useful methods for in-vivo combination tests in murine malaria parasites.

The opportunistic pathogen Pseudomonas aeruginosa secrets a capsule-like polysaccharide called alginate which is important for evasion of host defenses, especially in patients with suppressed immunity. Method of alginate determination has an important role in the study of microbial alginate. In this study, a novel method for alginate determination by highperformance liquid chromatography (HPLC) was introduced. Standard alginate was used for construction of standard curve and standard mucoid and non-mucoid strains of Pseudomonas aeruginosa were used as positive and negative samples respectively. The method of Toyoda was modified for determination of microbial alginate. HPLC determination was performed using a Resolve C18 column (3.9 × 150 mm, Waters, Milford, MA) and acetonitrile-water-butyl acetate (55: 42: 3) as the mobile phase at a flow rate of 0.6 ml/min and detection at 565 nm. The obtained data indicated that minimal detectable concentration of alginate by this method is 20 μg/ml. The method was linear over the range of 1-1000 μg/ml of alginate. The retention time was about 10 min. The proposed method was used for determination of alginate in standard mucoid and non-mucoid strains of Pseudomonas aeruginosa. The results of this study showed that the proposed method is a simple and valid method for bacterial alginate assay.

A simple and sensitive extractive spectrophotometric method is described for determination of tropicamide. The method is based on the reaction of tropicamide and bromocresol green. The ion-paired colored complex was extracted with chloroform at pH 3. The extracted complex showed maximum absorbance at 423 nm. The complex was stable up to 2 days and obeyed Beer's law over the concentration ranges of 1.32-100.81 μg/ml. No significant interference was observed from the excipients, coloring and flavoring agents commonly used in the tropicamide pharmaceutical preparations. The proposed method was applied successfully for determination of tropicamide in commercial eye drop dosage forms.

Licorice is obtained from Glycyrrhiza glabra (G. glabra) in Iran. Glycyrrhizin is the main constituent of G. glabra and has several pharmacological effects. It is hydrolyzed to glycyrrhetic acid (GA) in the intestine after oral administration. In this study, a novel HPLC method was used to determine the concentration of GA in rat plasma after oral administration of licorice aqueous extract. The method was linear (r2 >0.999) in the range of 0.1-5.0 μg/ml for GA. Maximum plasma concentration of GA was achieved 8 h after oral administration of licorice aqueous extract. The developed method was suitable for determination of GA in rat plasma.

Mefloquine (MFQ), as a racemic mixture is used for the prophylaxis and treatment of malaria. Stereoselective pharmacodynamic and pharmacokinetic differences have been observed for MFQ. In the present study, the human blood was spiked with racemic MFQ. The concentration of MFQ enantiomers in various blood fractions including packed erythrocyte layer, platelet rich plasma and platelet poor plasma was determined. The results showed that the ratio of (+)-MFQ was about 1.5 time higher than (-)-MFQ in packed erythrocyte layer. Results obtained from the separated erythrocytes spiked with racemic MFQ showed no significant difference between the enantiomer concentrations. It can be concluded that the stereoselective accumulation of MFQ enantiomers in erythrocytes might be in relation to protein binding or the presence of other blood cells.

Mefloquine, as a racemic mixture, is used for the treatment and prophylaxis of malaria. Stereoselective pharmacodynamic and pharmacokinetic differences has been observed for mefloquine. In this study a modified stereoselective HPLC method is presented for determination of mefloquine (MFQ) enantiomers in whole blood. The assay involved liquid-liquid extraction of MFQ from biological fluids with methyl tert-butyl ether in the presence of sodium hydroxide and derivatization of the residue by ()-1-(9-fluorenyl) ethyl chloroformate (FLEC) as chiral derivatizing reagent. Separation of the resulting diastereomers was performed on a Novapack C18 reversed-phase cartridge column using acetonitrile, water, glacial acetic acid (730:270:0.7, v/v/v) as the mobile phase with a flow-rate of 1 mL/min. Using 500 L of whole blood, the limit of determination was 50 ng/mL with fluorescence detection with excitation at 263 nm and emission at 475 nm for both enantiomers. This method is comparatively simple and practical for the determination of small amounts of mefloquine enantiomers.

A rapid and sensitive HPLC method was developed for determination of losartan in plasma. Losartan was extracted from plasma by a two-step extraction procedure using chloroform as extracting solvent in acidic medium. HPLC analysis was performed on a cyano reversed-phase column using phosphate buffer (pH 4.3), acetonitrile (750:250, v/v) as mobile phase with a flow rate of 0.9 mL/min. Sodium diclofenac was selected as internal standard. Excellent linearity between the peak area ratios and losartan concentrations over the range of 2-200 ng/mL of plasma was observed. The limit of determination with UV detection at 225 nm, with a CV < 5% was 2 ng/mL in 500 L of plasma sample. The assay was rapid, safe and reliable for use in pharmacokinetic studies of losartan in human being.

The in vitro activity of rac-mefloquine hydrochloride and its pure enantiomers was tested against a chloroquine-resistant (PF.IBS2) strain of Plasmodium falciparum. The parasite isolated from Iranian patients was cultured in vitro by the candle jar method described by Tranger and Jensen and was exposed to the racemic mefloquine or its enantiomers over the concentration range of 10-9 to 10-4 M. Neither rac-mefloquine nor the enantiomers showed antiparasitic activity at 10-9 M. The ()-mefloquine was more potent than the (-)-mefloquine and the racemate by IC50 equal to 1.17 µM in comparison to 4.09 µM.

Background-The mucoid strains of Pseudomonas aeruginosa produce a hyperviscous capsule, which has several roles in pathogenesis. In this study, the in vitro microscopic effects of sub-inhibitory concentrations of gentamicin on capsule production by mucoid Pseudomonas aeruginosa were investigated.Methods-The production of a capsule by the mucoid Pseudomonas aeruginosa cells cultured on agar media in the presence of sub-inhibitory concentrations of gentamicin was observed by light and electron microscopy. Results- Capsule production was reduced by 0.5 and 0.25 minimum inhibitory concentrations. The results showed a reduction in capsular size in the presence of sub-inhibitory concentrations of gentamicin. The size of the capsule in the presence of 0.5 MIC gentamicin was less than its size in 0.25 MIC gentamicin.Conclusion-The results confirm that the production of alginate was reduced and consequently, P. aeruginosa infections might be prevented by sub-inhibitory concentrations of gentamicin.

Abstract: Derivative spectrophotometry offers a useful approach for the analysis of drugs in multi-component mixtures. In this study a third-derivative spectrophotometry method was used for simultaneous determination of anthocyanoside and beta-carotene using the zero-crossing technique. The measurements were carried out at wavelengths of 625 and 540 nm for anthocyanoside and beta-carotene respectively. The method was found to be linear (r2>0.999) in the range of 125-750 µg/mL for anthocyanoside in the presence of 25 µg/mL beta-carotene at 625 nm. The same linear correlation was also obtained (r2>0.997) in the range of 6.25-37.50 µg/mL for beta-carotene in the presence of 500 µg/mL of anthocyanoside at 540 nm. The limit of determination was 125 and 6.25 µg/mL for anthocyanoside and beta-carotene respectively. The method was successfully applied for simultaneous determination of anthocyanoside and beta-carotene in pharmaceutical preparations without any interferences from excipients.