scholarly journals Comparative static and shaking culture of metabolite derived from methyl red degradation by Lysinibacillus fusiformis strain W1B6

2019 ◽  
Vol 6 (7) ◽  
pp. 190152 ◽  
Author(s):  
Ira Puspita Sari ◽  
Khanom Simarani
Keyword(s):  
Benzoic Acid ◽  
High Performance ◽  
Degradation Products ◽  
Culture Conditions ◽  
Methyl Red ◽  
Lysinibacillus Fusiformis ◽  
Significant Difference ◽  
Static Conditions ◽  
Azoreductase Activity ◽  
Amino Benzoic Acid

This paper reports on the comparative characteristics and properties of the metabolites derived from methyl red (MR) decolorization by Lysinibacillus fusiformis strain W1B6 under static and shaking conditions. A batch culture system was used to investigate the effect of aeration on azoreductase activity in the biodegradation process, transformation of colour removal and the metabolite products. Biodegradation analysis was monitored using Fourier transform infrared spectroscopy and high-performance liquid chromatography while metabolites were determined using gas chromatography–mass spectroscopy. Phytotoxicity and anti-microbial tests were also conducted to detect the toxicity of metabolites. The results showed that this strain grew more rapidly under shaking conditions while azoreductase activity increased more rapidly under static conditions. Despite that, no significant difference in the decolorization was observed under both static and shaking conditions with up to 96% and 93.6% decolorization achieved, respectively, within 4 h of incubation. MR was degraded into two fragmented compounds, i.e. 2-aminobenzoic acid and N,N -dimethyl-1.4-benzenediamine. The concentration of 2-amino benzoic acid was higher under static conditions resulting the biotransformation of 2-amino benzoic acid into methyl anthranilate more rapidly under static conditions. Other metabolites were also detected as intermediate biotransformation products and by-products. Less or no toxic effect was found in the metabolite degradation products under both culture conditions.

Validated Chromatographic and Spectrofluorimetric Methods for Analysis of Silodosin: A Comparative Study with Application of RP-HPLC in the Kinetic Investigation of Silodosin Degradation

2020 ◽  
Author(s):  
Shereen A Boltia ◽  
Mohammed Abdelkawy ◽  
Taghreed A Mohamed ◽  
Nahla N Mostafa
Keyword(s):  
Analytical Methods ◽  
High Performance ◽  
Degradation Products ◽  
Reversed Phase ◽  
Array Detector ◽  
Kinetic Investigation ◽  
First Derivative ◽  
Rp Hplc ◽  
Significant Difference

Abstract Background Stability indicating determination of pharmaceuticals is crucial, especially for drugs which have few published official analytical methods. Silodosin (SLD) is an FDA approved α1A-adrenoceptor blocker. Objective Efficient analytical methods were suggested, based on different instrumental techniques for quantification of SLD, besides conducting kinetic investigation of its degradation. Methods The first method is based on Reversed Phase High Performance Liquid Chromatography with Photodiode Array Detector (RP-HPLC-PDAD). Detection is done at wavelength 225 nm. The second method is focused on using High Performance Thin Layer Chromatography (HPTLC) and eluting the drug by solvent mixture followed by scanning at wavelength 270 nm. The third method depends on the First Derivative Synchronous Fluorescence Spectroscopy (1DSFS) for analysis of solutions of SLD and its acid and oxidative induced degradation products at Δλ = 90 nm, then determining the first derivative of the spectra and measuring peak amplitudes at 360 nm. Results Acceptable linearities were found in the concentration range of 0.50–90 μg/mL, 0.10–3.0 μg/band, and 0.05–0.50 µg/mL, for RP-HPLC-PDAD, HPTLC, and spectrofluorimetric methods, respectively. Conclusion Statistical analysis showed no significant difference between the suggested and the reported method. In monitoring the kinetics of SLD degradation, the order of reactions was determined and effects of degrading agent concentration and temperature on reaction rate were studied. Highlights Three analytical methods were developed for the determination of SLD based on RP-HPLC-PDAD, HPTLC, and 1DSFS in bulk and capsule dosage form. In addition, kinetic investigation of SLD degradation was performed using the developed RP-HPLC-PDAD method.

scholarly journals A Validated High-Performance Thin-Layer Chromatographic Method for the Simultaneous Determination of Zofenopril Calcium and Hydrochlorothiazide in the Presence of the Hydrochlorothiazide Impurities: Chlorothiazide and Salamide

2018 ◽  
Vol 101 (4) ◽  
pp. 1031-1041 ◽  
Author(s):  
Mamdouh R Rezk ◽  
Ahmed S Fayed ◽  
Hoda M Marzouk ◽  
Samah S Abbas
Keyword(s):  
Simultaneous Determination ◽  
High Performance ◽  
Degradation Products ◽  
Raw Materials ◽  
Drug Product ◽  
Hplc Method ◽  
Pharmaceutical Formulation ◽  
Significant Difference ◽  
Hptlc Method

Abstract The chromatographic analysis of either process-related impurities or degradation products is very important in the pharmaceutical industry. In this work, a simple, selective, and sensitive HPTLC method was developed and validated for the simultaneous determination of zofenopril calcium (ZOF) and hydrochlorothiazide (HCT) in the presence of the HCT impurities: A) chlorothiazide (CT) and B) salamide, in raw materials and in pharmaceutical formulation. The separation was carried out on HPTLC silica gel 60 F254 using ethyl acetate–glacial acetic acid–triethylamine (10 + 0.1 + 0.1, v/v/v) as a developing system. The separated bands were scanned densitometrically at 270 nm. Polynomial equations were used for the regression. Calibration curves were constructed for ZOF, HCT, CT, and salamide in the ranges of 0.5–10, 0.2–4, 0.05–1.4, and 0.05–1.0 μg/band, respectively. Different parameters affecting the suggested method, including developing systems of varying composition/ratios and different detection wavelengths, were studied to achieve the best resolution and precision with good sensitivity. System suitability parameters were also tested. The proposed method was validated as per the International Conference on Harmonization guidelines and was successfully applied for the quantification of the studied drugs in their pharmaceutical formulation, with no interference from excipients observed. The results obtained by the developed HPTLC method were compared statistically with those obtained by the reported HPLC method using Student’s t and F ratio tests, and no significant difference was obtained, indicating the ability of the proposed method to be used for routine analysis of drug product.

Immunoreactivity of Tissue Plasminogen Activator and of Its Inhibitor Complexes

1989 ◽  
Vol 61 (03) ◽  
pp. 409-414 ◽  
Author(s):  
M Rånby ◽  
G Nguyen ◽  
P Y Scarabin ◽  
M Samama
Keyword(s):  
Plasminogen Activator ◽  
Tissue Plasminogen Activator ◽  
Degradation Products ◽  
Gel Filtration ◽  
Free Form ◽  
Enzyme Linked Immunosorbent Assay ◽  
Plasma Samples ◽  
Significant Difference ◽  
Tissue Plasminogen ◽  
Pai 1

SummaryAn enzyme linked immunosorbent assay (ELISA) based on goat polyclonal antibodies against human tissue plasminogen activator (tPA) was evaluated. The relative immunoreactivity of tPA in free form and tPA in complex with inhibitors was estimated by ELISA and found to be 100, 74, 94, 92 and 8l% for free tPA and tPA in complex with PAI-1, PAI-2, α2-antiplasmin and C1-inhibitor, respectively. Addition of tPA to PAI-1 rich plasma resulted in rapid and total loss of tPA activity without detectable loss of ELISA response, indicating an immunoreactivity of tPA in tPA/PAI-1 complex of about l00%. Three different treatments of citrated plasma samples (acidification/reneutralization, addition of 5 mM EDTA or of 0.5 M lysine) prior to determination by ELISA all resulted in increased tPA levels. The fact that the increase was equally large in all three cases along with good analytical recovery of tPA added to plasffi, supported the notion that all tPA antigen present in plasma samples is measured by the ELISA. Analysis by ELISA of fractions obtained by gel filtration of plasma from a patient undergoing tPA treatment identified tPA/inhibitor complexes and free tPA but no low molecular weight degradation products of tPA. Determinations of tPA antigen were made at seven French clinical laboratories on coded and randomized plasma samples with known tPA antigen content. For undiluted samples there was no significant difference between the tPA levels found and those known to be present. The between-assay coefficient of variation was 7 to 10%. In conclusion, the ELISA appeared suited for determination of total tPA antigen in human plasma samples.

The Influence of Some Factors on Spirolactone Stability in Solution

2008 ◽  
Vol 59 (7) ◽  
Author(s):  
Daniela Lucia Muntean ◽  
Silvia Imre ◽  
Cosmina Voda
Keyword(s):  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
Uv Irradiation ◽  
High Performance ◽  
Degradation Products ◽  
Simultaneous Action ◽  
Ethanolic Solution ◽  
Degradation Processes ◽  
Stable Solutions ◽  
Preformulation Study

The influence of some factors on spironolactone stability in solution was studied, by applying high-performance liquid chromatography, as a part of a pharmaceutical preformulation study in order to obtain a spironolactone solution for alopecia treatment. Solutions of 1 mg/ml spironolactone in aqueous ethanolic solution 1 : 1 and in 20 mM cyclodextrines solutions (b-, hydroxi-b- and methyl-b-cyclodextrine) was used, maintained at 8 and 22 �C, protected from light and after UV irradiation at 254 nm. The main degradation products were 7a-thiospirolactone and canrenone. The most stable solutions were the alcoholic ones and with methyl-beta-cyclodextrine, but the simultaneous action of temperature and UV irradiation allowed degradation processes after one hour of exposure, more aggressive in the presence of methyl-beta-cyclodextrine. In conclusion, for alopecia treatment with spironolactone a 1 mg/mL ethanolic solution could be used and it is recommendable the protection of treated zone.

Recent Applications of High Performance Thin Layer Chromatography and Derivative Spectrophotometry in Pharmaceutical Analysis

2020 ◽  
Vol 16 (6) ◽  
pp. 671-689
Author(s):  
Marcin Gackowski ◽  
Marcin Koba ◽  
Katarzyna Mądra-Gackowska ◽  
Piotr Kośliński ◽  
Stefan Kruszewski
Keyword(s):  
Thin Layer ◽  
Thin Layer Chromatography ◽  
Pharmaceutical Analysis ◽  
High Performance ◽  
Degradation Products ◽  
Derivative Spectrophotometry ◽  
Accuracy And Precision ◽  
Post Marketing ◽  
Layer Chromatography

At present, no one can imagine drug development, marketing and post-marketing without rigorous quality control at each stage. Only modern, selective, accurate and precise analytical methods for determination of active compounds, their degradation products and stability studies are able to assure the appropriate amount and purity of drugs administered every day to millions of patients all over the world. For routine control of drugs simple, economic, rapid and reliable methods are desirable. The major focus of current scrutiny is placed on high-performance thin layer chromatography and derivative spectrophotometry methods, which fulfill routine drug estimation’s expectations [1-4]. The present paper reveals state-of-the-art and possible applications of those methods in pharmaceutical analysis between 2010 and 2018. The review shows advantages of high-performance thin layer chromatography and derivative spectrophotometry, including accuracy and precision comparable to more expensive and time-consuming methods as well as additional fields of possible applications, which contribute to resolving many analytical problems in everyday laboratory practice.

ICH/FDA Guidelines-Compliant Validated Stability-Indicating HPLC-UV Method for the Determination of Axitinib in Bulk and Dosage Forms

2020 ◽  
Vol 16 (8) ◽  
pp. 1106-1112
Author(s):  
Ibrahim A. Darwish ◽  
Nasr Y. Khalil ◽  
Mohammad AlZeer
Keyword(s):  
High Performance ◽  
Kinase Inhibitor ◽  
Degradation Products ◽  
Internal Standard ◽  
Dosage Forms ◽  
Uv Detector ◽  
Stability Indicating ◽  
Therapeutic Benefits ◽  
Relative Standard

Background: Axitinib (AXT) is a member of the new generation of the kinase inhibitor indicated for the treatment of advanced renal cell carcinoma. Its therapeutic benefits depend on assuring the good-quality of its dosage forms in terms of content and stability of the pharmaceutically active ingredient. Objective: This study was devoted to the development of a simple, sensitive and accurate stabilityindicating high-performance liquid chromatographic method with ultraviolet detection (HPLC-UV) for the determination of AXT in its bulk and dosage forms. Methods: Waters HPLC system was used. The chromatographic separation of AXT, internal standard (olaparib), and degradation products were performed on the Nucleosil CN column (250 × 4.6 mm, 5 μm). The mobile phase consisted of water:acetonitrile:methanol (40:40:20, v/v/v) with a flow rate of 1 ml/min, and the UV detector was set at 225 nm. AXT was subjected to different accelerated stress conditions and the degradation products, when any, were completely resolved from the intact AXT. Results: The method was linear (r = 0.9998) in the concentration range of 5-50 μg/ml. The limits of detection and quantitation were 0.85 and 2.57 μg/ml, respectively. The accuracy of the method, measured as recovery, was in the range of 98.0-103.6% with relative standard deviations in the range of 0.06-3.43%. The results of stability testing revealed that AXT was mostly stable in neutral and oxidative conditions; however, it was unstable in alkaline and acidic conditions. The kinetics of degradation were studied, and the kinetic rate constants were determined. The proposed method was successfully applied for the determination of AXT in bulk drug and dosage forms. Conclusions: A stability-indicating HPLC-UV method was developed and validated for assessing AXT stability in its bulk and dosage forms. The method met the regulatory requirements of the International Conference on Harmonization (ICH) and the Food and Drug Administration (FDA). The results demonstrated that the method would have great value when applied in quality control and stability studies for AXT.

Validated Stability Indicating HPTLC Method for the Estimation of Amoxapine in Different Stress Conditions

2019 ◽  
Vol 15 (3) ◽  
pp. 273-279
Author(s):  
Shweta G. Rangari ◽  
Nishikant A. Raut ◽  
Pradip W. Dhore
Keyword(s):  
High Performance ◽  
Limit Of Detection ◽  
Degradation Products ◽  
Analysis Data ◽  
Peak Height ◽  
Good Resolution ◽  
Stability Indicating ◽  
Limit Of Quantitation ◽  
Wide Range ◽  
Hptlc Method

Background:The unstable and/or toxic degradation products may form due to degradation of drug which results into loss of therapeutic activity and lead to life threatening condition. Hence, it is important to establish the stability characteristics of drug in various conditions such as in temperature, light, oxidising agent and susceptibility across a wide range of pH values.Introduction:The aim of the proposed study was to develop simple, sensitive and economic stability indicating high performance thin layer chromatography (HPTLC) method for the quantification of Amoxapine in the presence of degradation products.Methods:Amoxapine and its degraded products were separated on precoated silica gel 60F254 TLC plates by using mobile phase comprising of methanol: toluene: ammonium acetate (6:3:1, v/v/v). The densitometric evaluation was carried out at 320 nm in reflectance/absorbance mode. The degradation products obtained as per ICH guidelines under acidic, basic and oxidative conditions have different Rf values 0.12, 0.26 and 0.6 indicating good resolution from each other and pure drug with Rf: 0.47. Amoxapine was found to be stable under neutral, thermal and photo conditions.Results:The method was validated as per ICH Q2 (R1) guidelines in terms of accuracy, precision, ruggedness, robustness and linearity. A good linear relationship between concentration and response (peak area and peak height) over the range of 80 ng/spot to 720 ng/spot was observed from regression analysis data showing correlation coefficient 0.991 and 0.994 for area and height, respectively. The limit of detection (LOD) and limit of quantitation (LOQ) for area were found to be 1.176 ng/mL and 3.565 ng/mL, whereas for height, 50.063 ng/mL and 151.707 ng/mL respectively.Conclusion:The statistical analysis confirmed the accuracy, precision and selectivity of the proposed method which can be effectively used for the analysis of amoxapine in the presence of degradation products.

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