The purpose of this investigation was directed to propose sensitive, accurate and reproducible methods of analysis that can be applied to determine distigmine bromide (DTB), cyclopentolate hydrochloride (CPHC), diaveridine hydrochloride (DVHC) and tetrahydrozoline hydrochloride (THHC) drugs in pure form and pharmaceutical preparations via charge-transfer complex formation with 7, 7, 8, 8-tetracyanoquinodimethane (TCNQ) and tetracyanoethylene (TCNE) reagents. Spectrophotometric method involve the addition a known excess of TCNQ or TCNE reagents to DTB, CPHC, DVHC and THHC drugs in acetonitrile, followed by the measurement of the absorbance of the CT complexes at the selected wavelength. The reaction stoichiometry is found to be 1: 1 [drug]: [TCNQ or TCNE]. The absorbance is found to increase linearly with concentration of the drugs under investigation which is corroborated by the correlation coefficients of 0. 9954-0. 9981. The system obeys Beer’ s law for 6-400, 20-500, 1-180 and 60-560 μ g mL-1 and 80-600, 10-300, 1-60 and 80-640 μ g mL-1 for DTB, CPHC, DVHC and THHC drugs using TCNQ and TCNE reagents, respectively. The apparent molar absorptivity, sandell sensitivity, the limits of detection and quantification are also reported for the spectrophotometric method. Intra-and inter-day precision and accuracy of the method were evaluated as per ICH guidelines. The method was successfully applied to the assay of DTB, CPHC, DVHC and THHC drugs in formulations and the results were compared with those of a reference method by applying Student’ s t and F-tests. No interference was observed from common pharmaceutical excipients.

Background: Regarding the high prevalence of UTI (Urinary Tract Infection) and increasing tendency for using phenazopyridine, and also with respect to the problems originating in importing this product, the present study was achieved with the aim of synthesis and physicochemical control of phenazopyridine HCI. Materials and methods: Different techniques had been used for phenazopyridine synthesis, however, a technique with higher yield and purity was employed. Results: Final product was achieved with 91% yield and 99% purity, meanwhile, its physicochemical properties were in accordance with USP.Conclusion: Results have revealed that phenazopyridine synthesis with satisfactory purity is practical, here in Iran.

In this study, different derivative spectrophotometric methods are proposed for the simultaneous determination of chlorpheniramine maleate (CP), phenylephrine HCl (PE) and phenylpropanolamine HCl (PP) in their ternary mixtures and in pharmaceutical dosage forms. Spectra of single component and ternary mixtures of various concentrations and combinations from zero- to fourth-derivation were obtained. Also the spectra of the excipients including lactose, starch, and microcrystalline cellulose were obtained to study the possible interference from matrices. Zero-crossing derivative spectrophotometry based on recording the second-derivative curve for PE at 286.5 nm and fourth-derivative curve for PP at 220 nm were used for determining each component. Third component, CP, was determined by measuring absolute amplitudes at 265.8, 262.2, 269.5, and 273.8 nm in its second derivative spectra. Results showed that the matrices have no interferences. The calibration curves were linear in the range of 1-8 µg/ml for PE; 5-30 mg/ml for PP; and 2-8 mg/ml for CP. The limits of detection were 0.2 mg/ml for PE, 0.1 µg/ml for PP, and 0.3 µg/ml for CP. The mean percentage recoveries obtained for different synthetic mixtures by using this method were 95.3% with coefficient of variation of 4.3% for PE, 101.5% with coefficient of variation of 1.4% for PP, and 99.4% with coefficient of variation of 1.5% for CP. This method has been applied successfully for the determination of PE and PP in its combination with CP in Antihistamine Decongestant tablets with a high percentage of recovery, good accuracy and precision.

High soluability of nitrate ions in water cause the dysfunction of many existing treatment methods in the removal of this very dangerous ion from aqueous media. On the other hand, due to the need for in situ treatment methods, in particular for groundwater, the replacement of old inefficient methods with new compounds is required. In this study, for the first time, the efficiency of activated dendrimer-graphene oxide for nitrate removal from an aquatic solution was investigated. Experiments were performed in a batch reactor and the main factors of pH, reaction time, and concentration of PAMAM-GO were investigated. The highest removal efficiency was obtained as 90% at 0. 025mg/L activated dendrimer-graphene oxide, pH of 7. 5 and 15 min reaction time. The results showed that nitrate removal by activated dendrimergraphene oxide is correlated with nanocomposite concentration, contact time, pH and initial concentration of nitrate. It seems that ion exchange between nitrate and chloride is the main mechanism of nitrate removal by activated dendrimer-graphene oxide according to functionalization of activated dendrimer-graphene oxide using hydrochloric acid. This method can be used as a suitable method for in situ removal of nitrate from water and wastewater due to the desirable ability of the nanocomposite and its optimal compatibility with the environment.

In this research, the performance of diethylene glycol (DEG) as corrosion inhibitor on the corrosion of carbon steel A105 sample in 5 M hydrochloric acid and Persian Gulf seawater has been studied using potentiodynamic polarization electrochemical tests and weight loss measurements. The results showed that 50 and 150 ppm of DEG has maximum inhibition efficiency in 5 M hydrochloric acid and seawater, respectively. Also, it was demonstrated that DEG act as a mixed inhibitor in acidic media and as an anodic inhibitor in seawater. Investigation of temperature effect on the DEG performance revealed that the corrosion rate increases as the temperature increased but in 25oC DEG has the highest inhibition efficiency in seawater. Furthermore, it was elucidated that adsorption process of DEG on the steel surface in both media was best fitted with Langmuir isotherm and adsorption process was perform spontaneously.

In this paper, the photocatalytic degradation of Lidocaine HCl, an anesthetic was investigated in aqueous solution using CuO/ZnO as a photocatalyst. The degradation was studied under different conditions including the amount of the photocatalyst, irradiation time, initial concentration of drug, pH of the system, initial concentration, addition of oxidant on the reaction rate and anion presence.The results showed that the photocatalytic degradation of Lidocaine HCl was strongly influenced by these parameters. The best conditions for the photocatalytic degradation of Lidocaine HCl were obtained. The optimum amount of the photocatalyst used is 0.48 g/L. The photodegradation efficiency of Lidocaine HCl increases with the increase of the illumination time. It was found that the photodegradation efficiency decreased with increasing the initial concentration of Lidocaine HCl. The photodegradation efficiency of Lidocaine HCl was accelerated by adding a small amount of H2O2. The possible roles of the additives on the reactions and the possible mechanisms of effect were also discussed.

Introduction: The purpose of this study was to investigate and compare the effect of iron oxide nanoparticles on the adsorption of sulfur dioxide by modified zeolite with hydrochloric acid. In this investigation was used modified zeolite with HCl with and without iron oxide nanoparticles (Iron Oxide Nanoparticles@Clinoptilolite/HCl) as adsorbent. Materials and methods: Structural characteristics, chemical composition and specific surface area of adsorbent were determined using the FTIR, FESEM, EDX, Mapping, XRD, XRF and BET techniques. Glass cylinder filled with zeolite seeds and SO2 cylinder balanced with N2 gas was used for experiments. It was evaluated factors affecting SO2 uptake process including temperature and contact time, also thermodynamics and kinetics of adsorption. Sulfur dioxide adsorption of real sample was taken with both adsorbents. Results: Adsorption efficiency of SO2 in the synthetic and actual sample were %82. 8± 5. 5 and %67. 2± 7. 21 respectively, by modified zeolite with HCl and iron oxide nanoparticles in the optimum conditions of temperature of 25 ° C and duration 28. 5 min. As well as, removal percentage average was obtained in the synthetic and actual sample %46. 1± 4. 34 and %35. 8± 5. 85 respectively, by modified zeolite with HCl without nanoparticles in optimum condition of temperature of 25 ° C and contact time of 20. 5 min. The results showed that SO2 adsorption is an exothermic and spontaneous process and adsorption kinetics of sulfur dioxide by both adsorbent is more consistent Pseudo-second order kinetics model. Conclusion: The use of iron oxide nanoparticles on the zeolite can increase SO2 removal efficiency from the gas phase.