In this study, four different spectrophotometric methods were applied for determination of cimetidine and erythromycin ethylsuccinate drugs in pure form and in their pharmaceutical preparations. The suggested methods are simple, sensitive, accurate, not time consuming and inexpensive. The results showed the following: The first method: Based on the formation of ion pair complex of each drug with bromothymol blue (BTB) as a chromogenic reagent. The formed complexes were extracted with chloroform and their absorbance values were measured at 427.5 nm for cimetidine and 416.5nm for erythromycin ethylsuccinate; against their reagents blanks. Two different methods, univariate method and multivariate method, were used to obtain the optimum conditions for the spectrophotometric determination of the cited drugs via ion pair formation. The Multivariate method involves the simplex optimization in addition to design of experiment (DOE)for the case of cimetidine. The study shows that the optimum conditions for the instantaneous formation of the ion-pair complexes, in aqueous medium, were: solution pH is 5.5 and 4.0 for cimetidine and erythromycin ethylsuccinate respectively, when 0.5 ml of phthalate buffer is used followed by the addition of 1 ml of 0.038% (for cimetidine) and 0.020% (for erythromycin ethylsuccinate)of BTB reagent. Moreover, the influence of different factors affecting the chloroformic extraction of the formed complexes was studied in each case. It was found that 6 min (for the case cimetidine complex) and 3 min (for the case erythromycin ethylsuccinate) shaking with one portion of 5 mL of chloroform was enough for quantitative extraction of the mentioned complexes.
in this work the polymides were prepared as rthemally stable polymers by diffrent ways
Background: This review aimed at explaining different methods of canine retraction along the archwire. Methods: Searching for different methods of canine retraction using fixed orthodontic appliances was carried out using different databases, including PubMed Central, Science Direct, Wiley Online Library, the Cochrane Library, Textbooks, Google Scholar, Research Gate, and hand searching from 1930 till February 2022. Results: After excluding the duplicate articles, papers describing the methods of canine retraction along the archwires were included. The most commonly used methods are NiTi closed coil spring and elastic chain. Conclusions: Various methods of canine retraction along the archwires were explained in detail regarding their adv
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Background: This review aims to discuss various canine retraction techniques using frictionless mechanics. Methods: Between 1930 and February 2022, searches were conducted about various canine retraction techniques using fixed orthodontic appliances in various databases, including PubMed Central, Science Direct, Wiley Online Library, the Cochrane Library, Textbooks, Google Scholar, Research Gate, and manual searching. Results: After removing the duplicate articles, publications that described how to use archwires to perform canine retraction with the archwires were included. Conclusions: The pros and cons of various canine retraction techniques using archwires were thoroughly discussed. T-loop is the preferred spring of all because of it
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ABSTRACT
Naproxen(NPX) imprinted liquid electrodes of polymers are built using polymerization precipitation. The molecularly imprinted (MIP) and non imprinted (NIP) polymers were synthesized using NPX as a template. In the polymerization precipitation involved, styrene(STY) was used as monomer, N,N-methylenediacrylamide (N,N-MDAM) as a cross-linker and benzoyl peroxide (BPO) as an initiator. The molecularly imprinted membranes and the non-imprinted membranes were prepared using acetophenone(AOPH) and di octylphathalate(DOP)as plasticizers in PVC matrix. The slopes and detection limits of the liquid electrodes ranged from)-18.1,-17.72 (mV/decade and )4.0 x 10-
... Show MoreThe drug promethazine hydrochloride (PRZH) forms with rhodium (II) a colored chelate (?max = 472 nm) complex at (pH = 2.1) which is extractable with benzyl alcohol as organic solvent. Under the appropriate experimental conditions a calibration plot was set up from which some analytical parameter were derived and deduced by regression. Standard addition procedure was also adopted. It has been estimated that the concentration of the drug PRZH to be 24.89 mg per unit and 24.19 mg per unit for both calibrations. Under optimal conditions, the developed method has been achieved the following characteristics: LDR (30 – 150 µg ml-1 ) PRZH , RSD % ( 0.6 – 2.47 ) , sandell sensitivity( 0.0844 µg. cm -2 ) , LOD ( 1.66 µgml-1 ) , recovery
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In this work, a method for the simultaneous spectrophotometric determination of zinc which was precipitated into deionized water that is in a commercial distribution systems PVC pipe, is proposed using UV-VIS Spectrophotometer. The method based on the reaction between the analytes Zn2+ and 2-carboxy-2-hyroxy-5-sulfoformazylbenze (Zincon) at an absorption maximum of 620nm at pH 9-10. This ligand is selective reagent. Since the complex is colored (blue), its stoichiometry can be established using visible spectrometry to measure the absorbance of solutions of known composition. The stoichiometry of the complex was determined by Job’s method and molar ratio method and found to be 1:2 (M: L). A series of synthetic solution containing different
... Show MoreBased on the diazotization-coupling reaction, a new, simple, and sensitive spectrophotometric method for determining of a trace amount of (BPF) is presented in this paper. Diazotized metoclopramide reagent react with bisphenol F produces an orange azo-compound with a maximum absorbance at 461 nm in alkaline solution. The experimental parameters were optimized such as type of alkaline medium, concentration of NaOH, diazotized metoclopramide amount, order additions, reaction time, temperature, and effect of organic solvents to achieve the optimal performance for the proposed method. The absorbance increased linearly with increasing bisphenol F concentration in the range of 0.5-10 μg mL-1 under ideal conditions, with a correlati
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The reserve estimation process is continuous during the life of the field due to risk and inaccuracy that are considered an endemic problem thereby must be studied. Furthermore, the truth and properly defined hydrocarbon content can be identified just only at the field depletion. As a result, reserve estimation challenge is a function of time and available data. Reserve estimation can be divided into five types: analogy, volumetric, decline curve analysis, material balance and reservoir simulation, each of them differs from another to the kind of data required. The choice of the suitable and appropriate method relies on reservoir maturity, heterogeneity in the reservoir and data acquisition required. In this research, three types of rese
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This research foxed on the effect of fire flame of different burning temperatures (300, 400 and 500)oC on the compressive strength of reactive powder concrete (RPC).The steady state duration of the burning test was (60)min. Local consuming material were used to mixed a RPC of compressive strength around (100) MPa. The tested specimens were reinforced by (3.0) cm hooked end steel fiber of (1100) MPa yield strength. Three steel fiber volume fraction were adopted in this study (0, 1.0and 1.5)% and two cooling process were included, gradual and sudden. It was concluding that increasing burning temperature decreases the residual compressive strength for RPC specimens of(0%) steel fiber volume fraction by (12.16, 19.46&24.49) and (18.20, 27.77 &3
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Cefixime is an antibiotic useful for treating a variety ofmicroorganism infections. In the present work, tworapid, specific, inexpensive and nontoxic methods wereproposed for cefixime determination. Area under curvespectrophotometric and HPLC methods were depictedfor the micro quantification of Cefixime in highly pureand local market formulation. The area under curve(first technique) used in calculation of the cefiximepeak using a UV-visible spectrophotometer.The HPLC (2nd technique) was depended on thepurification of Cefixime by a C18 separating column250mm (length of column) × 4.6 mm (diameter)andusing methanol 50% (organic modifier) and deionizedwater 50% as a mobile phase. The isocratic flow withrate of 1 mL/min was applied, the temper
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