Relation between base hydrolysis and racemization at the asymmetric nitrogen center in cobalt(III) complexes of 4-(aminoethyl)-1,4,7,10-tetraazadecane. .pi.-Stabilization in the SN1CB intermediate

1969 ◽  
Vol 8 (8) ◽  
pp. 1595-1604 ◽  
Author(s):  
David A. Buckingham ◽  
P. A. Marzilli ◽  
Alan M. Sargeson
1966 ◽  
Vol 88 (20) ◽  
pp. 4630-4636 ◽  
Author(s):  
B. Halpern ◽  
A. M. Sargeson ◽  
K. R. Turnbull

Author(s):  
Vishal N Kushare ◽  
Sachin S Kushare

The present paper describes stability indicating high-performance thin-layer chromatography (HPTLC) assay method for Ozagrel in bulk drugs. The method employed TLC aluminium plates precoated with silica gel 60F-254 as the stationary phase. The solvent system consisted of toluene: methanol: triethylamine (6.5: 4.0: 0.1 v/v/v). The system was found to give compact spot for Ozagrel (Rf value of 0.40 ± 0.010). Densitometric analysis of Ozagrel was carried out in the absorbance mode at 280 nm. The linear regression analysis data for the calibration plots showed good linear relationship with r2 = 0.999 with respect to peak area in the concentration range 30 - 120 ng/spot. The developed HPTLC method was validated with respect to accuracy, precision, recovery and robustness. Also to determine related substance and assay determination of Ozagrel that can be used to evaluate the quality of regular production samples. The developed method can also be conveniently used for the assay determination of Ozagrel in pharmaceutical formulations. The limits of detection and quantitation were 4.069 and 12.332 ng/spot, respectively by height. Ozagrel was subjected to acid and alkali hydrolysis, oxidation, photochemical and thermal degradation. The drug undergoes degradation under acidic, basic, oxidation and heat conditions. This indicates that the drug is susceptible to acid, base hydrolysis, oxidation and heat. Statistical analysis proves that the method is repeatable, selective and accurate for the estimation of said drug. The proposed developed HPTLC method can be applied for identification and quantitative determination of Ozagrel in bulk drug and tablet formulation.


2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Dimal A. Shah ◽  
Ishita I. Gondalia ◽  
Vandana B. Patel ◽  
Ashok Mahajan ◽  
Usmangani Chhalotiya ◽  
...  

Abstract Background A sensitive, precise, and stability-indicating high-performance thin-layer chromatographic (HPTLC) method has been developed for the analysis of Remogliflozin etabonate in tablet formulation. HPTLC plates precoated with silica gel 60 F254 were used as the stationary phase; methanol: ethyl acetate: toluene: NH3 (2:4:4:0.1, v/v/v) was used as mobile phase, and densitometry was used for the quantitative estimation of the drug. The proposed method was validated with respect to linearity, accuracy, precision, and robustness and applied for the estimation of drug in tablet dosage form. Results The Rf value of Remogliflozin etabonate was observed to be 0.61. The densitometric estimation was performed in reflectance mode at 229 nm. The method was found to be linear in the range of 500–8000 ng/band for Remogliflozin etabonate. The possible degradation pathway was estimated by performing forced degradation studies. The degradant peaks were well resolved from the drug peak with acceptable resolution in their Rf value. Conclusion An accurate and precise high-performance thin-layer chromatographic method has been developed for the quantification of Remogliflozin etabonate in tablets. Forced degradation studies were performed, and drug was found to be highly susceptible to acid, base hydrolysis, and oxidative stress degradation and gets converted into active drug Remogliflozin. Both Remogliflozin etabonate and Remogliflozin bands were well resolved. The method was applied for the analysis of drug in tablet formulation, and it can be used for routine quality control analysis, as well as for the analysis of stability samples.


1969 ◽  
Vol 8 (11) ◽  
pp. 2504-2508 ◽  
Author(s):  
William Edward Jones ◽  
Robert B. Jordan ◽  
T. W. Swaddle

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