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Article
Spectrophotometric Determination of Ibuprofen and Nystatin Via Ion Pair Complex Formation Using Chromotrope 2R

Authors: Intisar A. Shihab --- Theia'a N. Al-Sabha
Journal: JOURNAL OF EDUCATION AND SCIENCE مجلة التربية والعلم ISSN: 1812125X Year: 2019 Volume: 28 Issue: 2 Pages: 289-299
Publisher: Mosul University جامعة الموصل

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Abstract

This research paper tackles a developed method for Ibuprofen and Nystatin drugs determination both in their pure form and pharmaceutical formulations. The proposed method is based on the formation of binary complexes (ion association complexes) between the above drugs and Chromotrope 2R (C2R) in acidic medium forming a reddish orange colours .The complexes show maximum absorption at 562 nm and 566 nm for Ibuprofen and Nystatin respectively. The method was adhering to the Beer's law over concentration range 10-90 and 2-40 µg/ml with molar absorptivity values 1.36×103 and 7.59×103 l. mol-1. cm-1and average recovery 99.77% and 100.60 % for the above mentioned drugs respectively. No observed interferences appeared from the excipients commonly existed in pharmaceuticals. Successfully, application for both Ibuprofen and Nystatin was conducted in their pharmaceutical formulations.


Article
Substituent Effect on the Association Phenomenon of an Aqueous Solution of Benzylidene Substituted Aniline at Different Temperatures
دراسة تأثير المعوضات على ظاهرة التجمع الأيوني للمحاليل المائية للبنزيلدين أنيلين المعوض عند درجات حرارية مختلفة

Authors: Mohammed A. Al-Iraqi محمد احمد العراقي --- Yaser O. Al-Allaf ياسر عمر العلاف --- Kawther H. Al-Naimi كوثر حسين النعيمي
Journal: Rafidain journal of science مجلة علوم الرافدين ISSN: 16089391 Year: 2013 Volume: 24 Issue: 3E Pages: 51-65
Publisher: Mosul University جامعة الموصل

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Abstract

Conductivity parameters of an aqueous solution of benzylidene substituted anilines (I-IV) have been determined at five different temperatures in the range of 283.15-318.15 ºK, through accurate conductance measurements. The obtained data were analyzed in accordance to Lee-Wheaton equation taking into account the activity of the electrolyte in the solution. The conductance measurement results were used to determine the association constants (KA) of ion-pairs, the mean distance between ions in solution, in addition to the molar conductance at infinite dilution (Λo¬) for the free ion in the solution. The dependence of (KA) values on the temperature has been examined by plotting Log KA against the reciprocal values of temperature (1/T), which showed linear relationship, where (KA) values decrease with increasing temperature. Moreover, the enthalpy (ΔH), Gibbs free energy (ΔG) and the entropy (ΔS) have been derived from this linear relationship.

تم تقدير دوال التوصيلية للمحاليل المائية للبنزيلدين أنيلين المعوض(I-IV) عند خمس درجات حرارية في المدى (383.15-318.15 ºK) من خلال قياسات التوصيلية الدقيقة. تم تحليل النتائج باستخدام معادلة لي-ويتون مع الأخذ بنظر الإعتبار فعالية الإلكتروليت في المحلول. أستخدمت قياسات التوصيلية في تقدير ثابت التجمع الأيوني (KA) للمزدوج الأيوني، ومعدل المسافة بين الأيونات في المحلول فضلا عن حساب التوصيلية المولارية عند التخفيف النهائي (Λo) للأيون الحر في المحلول. درس تأثير درجة الحرارة على قيم ثابت التجمع الأيوني من خلال رسم العلاقة بين Log KA ضد مقلوب درجة الحرارة (1/T) والتي أعطت علاقة خطية، إذ انخفضت قيمة (KA) بزيادة درجة الحرارة، فضلا عن ذلك حسبت قيم المحتوى الحراري (ΔH) والطاقة الحرة (ΔG) والعشوائية (ΔS) من العلاقة الخطية هذه.


Article
Studies 0n Ion Association of Some Α-Amino Acids with L-Ascorbic Acid In Aqueous Solution at Different Temperature

Author: Muhammed J. Kadhim
Journal: Iraqi Journal of Science المجلة العراقية للعلوم ISSN: 00672904/23121637 Year: 2019 Volume: 60 Issue: 1 Pages: 1-11
Publisher: Baghdad University جامعة بغداد

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Abstract

Molar conductivity of ascorbic acid (AA) with some α–amino acids (glycine(Gly), methionine (Met), cysteine (Cys) and tryptophan (Trp)) in aqueous solutionwas measured at range temperatures from 298 K to 313 K. Λo. The limiting molarconductivity, KA, the association constant was calculated using the Shedlovskymethod, and R, the association distance calculated by Stokes–Einstein equation. Thethermodynamic parameters (The heat of association ΔHo, the change in Gibbs freeenergy ΔGo, the change of entropy ΔSo), and (ΔES), the activation energy were alsocalculated. All of the results obtained were discussed. The data showed theincreasing in Λo, with the increasing of temperature. The positive values for (ΔSo)and (ΔES) showed a decrease in solvation of ion–pair and signifying the highermobility of the ions. The negative value of ΔHo, refers that the association processesare exothermic. The negative values of ΔGo, are for ion association in aqueoussolution and increase with the increase in temperature.

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