Determination of Ferrous Iron in Ferric Chloride Hexahydrate
Bai Xiaoguang,
Wang Zhengda,
Wu Xudong,
Duan Shufen,
Liu Aihua,
Cheng Xiao
Issue:
Volume 7, Issue 1, January 2021
Pages:
1-4
Received:
25 March 2019
Accepted:
24 June 2020
Published:
10 February 2021
Abstract: Objective: As a pharmaceutical raw material, ferric chloride hexahydrate has been included in the British Pharmacopoeia, the European Pharmacopoeia (2008) and the United States Pharmacopoeia (2015), and there are detailed discussions on quality standards and testing methods. Ferric chloride hexahydrate has not been included in the Chinese Pharmacopoeia. This study is the part of research to establish a spectrophotometric method for the determination of ferrous iron in ferric chloride hexahydrate. In this study, the two methods were discussed in detail, and the spectrophotometric method for detecting the content of ferrous iron in ferric chloride hexahydrate was proposed. Methods: The detection method on ferrous iron in ferric chloride hexahydrate among European pharmacopoeia, United States pharmacopoeia and Chemical Reagent Ferric Chloride Hexahydrate (HG/T3474-2014) of China's Chemical Industry were compared. The last two methods were not easy to operation. On the basis of the European pharmacopoeia, a method was proposed that after Fe3+ were screened with H3PO4, Fe2+ was measured by spectrophotometry, and the method was verified by experiments. Results and Conclusion: The spectrophotometry method is easy to operate and has good reproducibility. The content of ferrous iron can be calculated semi-quantitatively by masking ferric iron with H3PO4 and spectrophotometric determination of ferrous ion content. Therefore, the method established in this study can more clearly detect whether the ferrous content in ferric chloride hexahydrate is up to standard.
Abstract: Objective: As a pharmaceutical raw material, ferric chloride hexahydrate has been included in the British Pharmacopoeia, the European Pharmacopoeia (2008) and the United States Pharmacopoeia (2015), and there are detailed discussions on quality standards and testing methods. Ferric chloride hexahydrate has not been included in the Chinese Pharmacop...
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Stability of Reconstituted Amoxicillin and Potassium Clavulanate Oral Suspensions Marketed in the Democratic Republic of the Congo
Mankulu Kakumba Jocelyn,
Mavanga Mabaya Timothy,
Bayebila Menanzambi Tresor,
Tshienda Katende Milka,
Mbenza Puati Adelard,
Mbinze Kindenge Jeremi,
Kimbeni Malongo Tresor
Issue:
Volume 7, Issue 1, January 2021
Pages:
5-12
Received:
14 December 2020
Accepted:
22 December 2020
Published:
23 February 2021
Abstract: Amoxicillin and Clavulanate potassium oral suspensions are one of antibiotics combination mainly available as dry powders for reconstitution. Made of a β-lactam molecule with a β-lactamase inhibitor, this combination existence can be justified by the potency of Clavulanate potassium which protects Amoxicillin against bacteria producing β-lactamases. Once reconstituted, suspension in single dose bag need to be taken by patient on daily basis following the medical prescription and the one in bottle to be taken according to the medical prescription and the remaining part (in the same container) kept refrigerated in order to get the optimal benefit from the drug. This study investigated the stability of Amoxicillin and Clavulanate potassium suspension both in bags (sachets) for single dose per daily-usage and in bottles for multiple dose usage. The last were reconstituted using distilled water and stored in refrigerator and the previous were instantly reconstituted before measurement. The stability evaluation was conducted on three brands (Six samples totally, two per brand including bottle and sachet for each brand) and for duration of seven days using a validated HPLC method. The evaluation was based on the measurement of pH values, color observation of reconstituted suspensions stored under refrigerator during 7 days and the active compounds concentrations determination. After analysis, no change was observed in pH values and a small change of color for multiple dose presentations stored in refrigerator. And the concentrations of suspensions evaluated in day 1 and day 7 showed over 90% up to seventh day under same storage conditions for both of the Amoxicillin and Clavulanate potassium pharmaceutical presentations. As the study aimed to assess the stability of the suspension in single-dose from bag presentation and in multiple-dose from suspension in bottle, we observed that the reconstituted suspension in distilled water of Amoxicillin + Clavulanate potassium stored in refrigerator is stable for seven days of use, independently from their pharmaceutical presentations either for oral suspensions (powders) in bottles or those in bags for single use after reconstitution.
Abstract: Amoxicillin and Clavulanate potassium oral suspensions are one of antibiotics combination mainly available as dry powders for reconstitution. Made of a β-lactam molecule with a β-lactamase inhibitor, this combination existence can be justified by the potency of Clavulanate potassium which protects Amoxicillin against bacteria producing β-lactamases...
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Tandem Cycloaddition-Cycloreversion of 2-pyrone and 1,4-oxazinone with Acetylene - A DFT Insight
Padmanaban Kalpana,
Lakshminarayanan Akilandeswari,
Ponnambalam Venuvanalingam
Issue:
Volume 7, Issue 1, January 2021
Pages:
13-21
Received:
5 December 2020
Accepted:
18 January 2021
Published:
27 February 2021
Abstract: Reaction of either 2-pyrone or 1,4-oxazinone with acetylene follows the sequence of cycloaddition - cycloreversion through concerted mechanism. Transition states for both cycloaddition and cycloreversion pathways have been obtained in both the cases by modelling the reactions at B3LYP/6-31g (d) level. Cycloreversion is faster than cycloaddition in the case of 2-pyrone due to the enhancement of aromaticity resulting the product as benzene. In contrast, oxazinone has rapid cycloaddition. It is ascribed to the presence of nitrogen in this system. Removal of either CO2 or HCN is plausible in this mechanism to complete the reaction. Even though two pathways are feasible for cycloreversion, CO2 extrusion is more preferable than HCN elimination. In these two studied molecules, there is an enhancement of aromaticity up to transition states like any other pericyclic reaction and further it diminishes during cycloaddition. Further, aromaticity is specifically augmented in cycloreversion phase during CO2 elimination resulting to yield pyridine whereas competitive HCN elimination results in the formation of 2-pyrone which is less facile. In both the molecules the aromatic enhancement of the cycloreversion is substantiated through the study of magnetic susceptibility of the ring fragment along the reaction coordinate. Further the study also reveals the effect of halogen substituted at different carbons of 2-pyrone ring.
Abstract: Reaction of either 2-pyrone or 1,4-oxazinone with acetylene follows the sequence of cycloaddition - cycloreversion through concerted mechanism. Transition states for both cycloaddition and cycloreversion pathways have been obtained in both the cases by modelling the reactions at B3LYP/6-31g (d) level. Cycloreversion is faster than cycloaddition in ...
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