Spectroscopic Studies of the Electron Donor-Acceptor Interaction of Chloroquine Phosphate with Chloranilic Acid

Purpose: The electron donor-acceptor interaction between drugs which act as electron donors and some electron-deficient compounds (&#960 acceptors) has severally been utilized as an analytical tool for the quantitation and qualitative assessment of such drugs. The objective of this study, therefore, was to develop an assay procedure for dosage forms of chloroquine phosphate based on its reaction with chloranilic acid which resulted in the formation of a charge-transfer complex. Methods: The complex formation between chloroquine phosphate and chloranilc acid as evidenced by the instantaneous change in colour of a solution of chloranilic acid in dioxan from yellow to purple upon addition of a solution of chloroquine phosphate in chloroform was monitored spectrophotometrically to determine the wavelength of maximum absorption. The stoichiometry of the complex formed was evaluated using the Job\'s continuous variation method while the thermodynamics of the complex was evaluated spectrophotometrically with the aid of the Benesi-Hildebrand plot. Results: Spectrophotometric absorption studies showed evidence of the formation of strongly bonded and highly stable charge-transfer complex between chloroquine phosphate and chloranilic acid in a 3:2 stoichiometry in non-aqueous medium. The transitions involved were detected at wavelengths longer than those of the individual pure substances in the visible region of the spectrum. Conformity with Beer\'s law was evident over the concentration range 0.8 – 8.0 mg/100 ml of chloroquine phosphate; thus making it possible for an accurate quantitative determination of the drug. Conclusion: The studied complexation phenomenon formed a basis for the quantitative determination of both pure samples and individual dose units of chloroquine phosphate and is considered a simple, sensitive and precise analytical tool with high accuracy for routine analysis of chloroquine phosphate in developing countries where sophisticated analytical instruments may not be available. Keywords: Spectroscopic studies, Electron Donor-Acceptor Interaction, Chloroquine phosphate, Chloranilic acid.Tropical Journal of Pharmaceutical Research Vol. 8 (1) 2009: pp. 87-9

Spectrophotometric Determination and Thermodynamic Parameters of Charge Transfer Complexation Between Stavudine and Chloranilic Acid

Purpose: The official assay methods for most antiretroviral drugs are limited by cost and unavailability of good test equipment in several developing countries. Therefore, this study investigates the use of charge transfer complexation in the spectrophotometric assay of stavudine as an alternative method to conventional methods.Methods: Charge transfer complex formation between stavudine (n-donor) and chloranilic acid (Π-acceptor) in 1,4-dioxan using a spectrophotometer was employed. Thermodynamic parameters of the complex formed were determined. The proposed method was employed in the analysis of commercially available stavudine dosage form.Results: The wavelength of maximum absorption (λmax) of the complex was at 526 nm compared to 457 nm for p-acceptor alone. Beer’s law was obeyed in the range of 5 - 40 mg % while the stoichiometry of the complex was found to be 2:1. The complex formed was still stable 24 h later. Its formation was spontaneous with a ΔHo of -3.78×103 J/mol. The standard entropy change was from 12.18 ± 0.78 to 11.08 ± 1.23 cal/deg/mol over the temperature range of 30 - 60 oC while molar absorptivity decreased from 2.45×105 to 1.2×105 over the same temperature range. The assay result of the standard stavudine solution was of high accuracy with a recovery value of 99.85 ± 1.95 %.Conclusion: The proposed method is reliable and reproducible and should be suitable for the quality control of stavudine in bulk and dosage forms.Keywords: Assay, Charge transfer, Stavudine, Spectrophotometric analysis, Chloranilic acid, Thermodynamic

Hypoglycemic Activity of the Extract and Fractions of Anthocleista vogelii (Planch) Stem Bark

Purpose: To investigate the hypoglycemic effect of the methanol extract and fractions of Anthocleista vogelii stem bark.Methods: The methanol extract of A. vogelii stem bark (ME) was subjected to gradient chromatographic separation using four solvents - chloroform, ethyl acetate, acetone and water - to afford the respective fractions - CF, EF, AF and WF. ME was administered orally to normoglycemic rats at 200 and 400 mg/kg and fasting blood glucose (FBG) monitored for 6 h. Alloxan-induced diabetic rats were also treated orally with ME and the various fractions (each at 200 mg/kg and 400 mg/kg), with glibenclamide(0.2 mg/kg) and normal saline (2 ml/kg) serving as standard and control, respectively. ME and the fractions were also subjected to phytochemical analysis following standard procedures.Results: The extract possessed comparable hypoglycemic effect to glibenclamide in healthy rats. The extract and its fractions also exhibited significant (p < 0.05) antidiabetic effect. ME, CF, EF, AF and WF each at 400 mg/kg, produced maximum reduction (64.10, 38.53, 36.50, 60.77 and 12.79 %, respectively) in FBG of the animals after 6 h, compared to 53.77 % for glibenclamide. Presence of alkaloids, carbohydrates, reducing sugars, saponins, flavonoids, glycosides, steroids, terpenoids, tannins, proteins, fats and oils were observed in ME, EF and AF. Alkaloids,  flavonoids, steroids, terpenoids, fats and oil were also detected in CF while WF showed the presence of carbohydrates, glycosides, saponins and proteins.Conclusion: This study establishes the antidiabetic activity of the stem bark of A. vogelii. The acetone fraction is the most active antidiabetic fraction.Keywords: Anthocleista vogelii, Antidiabetic, Hyperglycemia, Hypoglycemia, Phytochemical analysi

PHYTOCHEMISTRY AND ANTIMICROBIAL ACTIVITY OF METHANOLIC STEM EXTRACT OF BOMBAX BUONOPOZENSE P.BEAUV (SILK COTTON TREE)

Background: The aim and objective of this study was to evaluate methanolic extract of Bombax buonopozense (stem) for antimicrobial and phytochemical screening. Methods: The methanolic stem extract of B. buonopozense with documented ethno-medicinal  applications were fractionated in different solvents (n-hexane, chloroform, ethyl acetate, n-butanol and water) and subjected to phytochemical screening and antimicrobial activity against some disease-causing microorganisms including gram positive and gram negative (Staphylococcus aureus, Salmonella spp and Escherichia coli). The antimicrobial tests were carried out in triplicates, the data obtained were subjected to one-way ANOVA using statistical package for social science (SPSS). Results: Phytochemical screening revealed the presence of Alkaloids, saponins, saponin glycosides, Tannins, hydrolysable Tannins, steroids and triterpenoids, flavonoids, phenols and volatile oils. Each fractions of the extract demonstrated antibacterial activity against all the organisms tested. MIC values of each fractions revealed strong inhibition against all the organisms tested. The methanolic stem extract of B. buonopozense in chloroform, water, ethyl acetate, n-hexane and n-butanol showed the following MIC values. S. aureus. 6.25, 25, 12.5, 6.25, and 12.5. E. coli  100, 100, 50, 6.25 and 12.5. Salmonella spp. 3.125, 12.5, 25, 3.125 and 12.5 respectively. Conclusion: This study shows that the extract posses’ antimicrobial properties which can be used as alternatives to conventional antibiotics.                           Peer Review History: Received: 25 August 2022; Revised: 8 October; Accepted: 8 November, Available online: 15 November 2022 Academic Editor: Dr. Jennifer Audu-Peter, University of Jos, Nigeria, [email protected] Received file:                             Reviewer's Comments: Average Peer review marks at initial stage: 5.0/10 Average Peer review marks at publication stage: 7.0/10 Reviewers: Dr. Sangeetha Arullappan, Universiti Tunku Abdul Rahman, Malaysia, [email protected] Prof. Ali Gamal Ahmed Al-kaf, Sana'a university, Yemen, [email protected] Similar Articles:   IN -VIVO ANTI-DIARRHOEAL ACTIVITY OF METHANOL EXTRACT OF BOMBAX BUONOPOZENSE CRITICAL REVIEW ON BOMBAX CEIBA, ALOE VERA AND XIMENIA AMERICAN

Spectroscopic Studies of the Electron Donor-Acceptor Interaction of Chloroquine Phosphate with Chloranilic Acid

Purpose: The electron donor-acceptor interaction between drugs which act as electron donors and some electron-deficient compounds (π acceptors) has severally been utilized as an analytical tool for the quantitation and qualitative assessment of such drugs. The objective of this study, therefore, was to develop an assay procedure for dosage forms of chloroquine phosphate based on its reaction with chloranilic acid which resulted in the formation of a charge-transfer complex. Methods: The complex formation between chloroquine phosphate and chloranilc acid as evidenced by the instantaneous change in colour of a solution of chloranilic acid in dioxan from yellow to purple upon addition of a solution of chloroquine phosphate in chloroform was monitored spectrophotometrically to determine the wavelength of maximum absorption. The stoichiometry of the complex formed was evaluated using the Job’s continuous variation method while the thermodynamics of the complex was evaluated spectrophotometrically with the aid of the Benesi-Hildebrand plot. Results: Spectrophotometric absorption studies showed evidence of the formation of strongly bonded and highly stable charge-transfer complex between chloroquine phosphate and chloranilic acid in a 3:2 stoichiometry in non-aqueous medium. The transitions involved were detected at wavelengths longer than those of the individual pure substances in the visible region of the spectrum. Conformity with Beer’s law was evident over the concentration range 0.8 – 8.0 mg/100 ml of chloroquine phosphate; thus making it possible for an accurate quantitative determination of the drug. Conclusion: The studied complexation phenomenon formed a basis for the quantitative determination of both pure samples and individual dose units of chloroquine phosphate and is considered a simple, sensitive and precise analytical tool with high accuracy for routine analysis of chloroquine phosphate in developing countries where sophisticated analytical instruments may not be available

Spectroscopic Studies of the Electron Donor-Acceptor Interaction of Chloroquine Phosphate with Chloranilic Acid

Purpose: The electron donor-acceptor interaction between drugs which act as electron donors and some electron-deficient compounds (π acceptors) has severally been utilized as an analytical tool for the quantitation and qualitative assessment of such drugs. The objective of this study, therefore, was to develop an assay procedure for dosage forms of chloroquine phosphate based on its reaction with chloranilic acid which resulted in the formation of a charge-transfer complex. Methods: The complex formation between chloroquine phosphate and chloranilc acid as evidenced by the instantaneous change in colour of a solution of chloranilic acid in dioxan from yellow to purple upon addition of a solution of chloroquine phosphate in chloroform was monitored spectrophotometrically to determine the wavelength of maximum absorption. The stoichiometry of the complex formed was evaluated using the Job’s continuous variation method while the thermodynamics of the complex was evaluated spectrophotometrically with the aid of the Benesi-Hildebrand plot. Results: Spectrophotometric absorption studies showed evidence of the formation of strongly bonded and highly stable charge-transfer complex between chloroquine phosphate and chloranilic acid in a 3:2 stoichiometry in non-aqueous medium. The transitions involved were detected at wavelengths longer than those of the individual pure substances in the visible region of the spectrum. Conformity with Beer’s law was evident over the concentration range 0.8 – 8.0 mg/100 ml of chloroquine phosphate; thus making it possible for an accurate quantitative determination of the drug. Conclusion: The studied complexation phenomenon formed a basis for the quantitative determination of both pure samples and individual dose units of chloroquine phosphate and is considered a simple, sensitive and precise analytical tool with high accuracy for routine analysis of chloroquine phosphate in developing countries where sophisticated analytical instruments may not be available