scholarly journals Development and Validation of a Method for the Quantification of an Alkaloid Fraction ofHimatanthus lancifolius(Muell. Arg.) Woodson by Ultraviolet Spectroscopy

2013 ◽  
Vol 2013 ◽  
pp. 1-5
Author(s):  
Patrícia M. S. S. Barros ◽  
Nádia M. G. de Couto ◽  
Andressa S. B. Silva ◽  
Wagner L. R. Barbosa
Keyword(s):  
High Selectivity ◽  
Ultraviolet Spectroscopy ◽  
National Agency ◽  
Quantification Method ◽  
Alkaloid Fraction ◽  
Precision And Accuracy ◽  
Efficacy Parameters ◽  
Dried Extract ◽  
Development And Validation ◽  
Derivatives Of

For the registration of phytomedicines and their availability to the population, National Agency of Sanitary Surveillance (ANVISA) establishes quality, security, and efficacy parameters, stipulating control requirements similar to those applied to synthetic medicines. This work reports the investigation of the bark ofHimatanthus lancifoliusand its extracts aiming to contribute to the standardization of derivatives of this plant species. The developed quantification method shows high selectivity at 281nm, which confers confidence to the detection of the alkaloids. The method is robust, according to the current regulation, and shows linearity, precision, and accuracy, beside accessibility and simplicity in execute. The pH 10 alkaloid fraction obtained from the aqueous extract of the analyzed sample represents 0.219% in the dried extract. These results contribute for reducing the lack of methods for the quality control of phytomedicines prepared fromH. lancifolius.

Development and Validation of an LC-MS/MS Method for Simultaneous Determination of Canagliflozin and Metformin HCl in Rat Plasma and its Application

2020 ◽  
Vol 16 (6) ◽  
pp. 752-762
Author(s):  
Vivek Nalawade ◽  
Vaibhav A. Dixit ◽  
Amisha Vora ◽  
Himashu Zade
Keyword(s):  
Internal Standard ◽  
Rat Plasma ◽  
Precipitation Method ◽  
Herbal Extracts ◽  
One Step ◽  
Precision And Accuracy ◽  
Development And Validation ◽  
The Impact ◽  
Metformin Hcl

Background: Food and herbal extracts rich in Quercetin (QRT) are often self-medicated by diabetics and can potentially alter the pharmacokinetics (PK) of Metformin HCl (MET) and Canagliflozin (CNG) leading to food or herb-drug interactions and reduced therapeutic efficacy. However, the impact of these flavonoids on the pharmacokinetic behaviour of MET and CNG is mostly unknown. Methods: A simple one-step protein precipitation method was developed for the determination of MET and CNG from rat plasma. The mobile phase chosen was MeOH 65% and 35% water containing 0.1% formic acid at a flow rate of 1mL/min. Results: The retention time of MET, internal standard (Valsartan) and CNG was 1.83, 6.2 and 8.2 min, respectively. The method was found to be linear in the range of 200 - 8000 ng/mL for CNG and 100 = 4000 ng/ml for MET. Precision and accuracy of the method were below 20% at LLOQ and below 15% for LQC, MQC, and HQC. Conclusion: The method was successfully applied for the determination of PK of MET and CNG by using 100 μL of rat plasma. QRT co-administration affects the PK parameters of MET and CNG. This alteration in PK parameters might be of significant use for clinicians and patients.

Selective Determination of Entecavir in the Presence of Its Oxidative Degradate by Spectrophotometric and Chromatographic Methods

2021 ◽  
Author(s):  
Heba M El-Sayed ◽  
Laila E Abdel Fattah ◽  
Hisham E Abdellatef ◽  
Maha A Hegazy ◽  
Mai M Abd El-Aziz
Keyword(s):  
High Selectivity ◽  
Oxidative Degradation ◽  
Hplc Method ◽  
Peak Amplitude ◽  
Quality Analysis ◽  
Official Method ◽  
Selective Determination ◽  
Significant Difference ◽  
Development And Validation

Abstract Background Entecavir (ENT) is an antiretroviral agent prescribed for treatment of HBV and HIV. Objective Development and validation of three simple, sensitive, selective, and precise methods for determination of ENT in presence of its oxidative degradation product (ENT deg.). Methods The first method was based on second derivative (D2) spectrophotometry through measuring the peak amplitude of D2 spectra at 293.6 nm. The second one is mean centering of the ratio spectra (MCR), which allowed measuring the peak amplitude at 280.0 nm. While the third method was HPLC; where ENT was separated from ENT deg. using Zobrax C18column and methanol: water (30:70, v/v), pH 3 as a mobile phase. The three developed methods were validated according to ICH guidelines. Results Linearity range of ENT was 5.00–50.00 μg/mL for both D2and MCR. However, higher sensitivity was achieved using HPLC (1.00–50.00 μg/mL). Accuracy of ENT were 100.60%±0.547, 101.55%±1.2071 and 100.61%±1.207 for D2, MCR and HPLC methods, respectively, and precision was within 1.280. Conclusions The developed methods were successfully applied for the determination of ENT in Tecavir® tablets without interference from ENT deg. They showed no significant difference compared with the official method as well as they could be applied in the quality analysis of ENT with high selectivity, accuracy, and precision. Highlights ENT was quantified using two spectrophotometric (D2 and MCR) methods and an HPLC method in presence of ENT deg. The proposed methods were applied to analysis of ENT tablets with high selectivity, sensitivity, and accuracy.

Development and Validation of an HPLC Method for Determination of Spirotetramat and Spirotetramat cis enol in Various Vegetables and Soil

2013 ◽  
Vol 96 (3) ◽  
pp. 670-675 ◽  
Author(s):  
Balwinder Singh ◽  
Kousik Mandal ◽  
Sanjay K Sahoo ◽  
Urvashi Bhardwaj ◽  
Raminderjit Singh Battu
Keyword(s):  
Analytical Method ◽  
Anhydrous Sodium Sulfate ◽  
Hplc Method ◽  
Array Detector ◽  
Photodiode Array Detector ◽  
Photodiode Array ◽  
Precision And Accuracy ◽  
Hplc Grade Acetonitrile ◽  
Development And Validation

Abstract An easy and simple analytical method was standardized and validated for the estimation of residues of spirotetramat and its metabolite spirotetramat cis enol in various substrates: okra fruits, brinjal leaves and fruits, green chili, red chili, and soil. The samples were extracted with acetonitrile, diluted with brine solution, partitioned into dichloromethane, dried over anhydrous sodium sulfate, and cleaned up by treatment with activated charcoal powder. Final clear extracts were concentrated under vacuum and reconstituted with HPLC grade acetonitrile. Residues were estimated using HPLC with a photodiode array detector and a C18 column, and confirmed by HPTLC. Acetonitrile was used as the mobile phase at 0.4 mL/min. Both spirotetramat and spirotetramat cis enol presented distinct peak at retention times of 8.518 and 7.598 min, respectively. Consistent recoveries ranging from 82 to 97% for spirotetramat and spirotetramat cis enol were observed when samples were spiked at 1.00 to 0.03 mg/kg levels. The LOQ of the method was found to be 0.03 mg/kg. The analytical method was validated in terms of parameters, including selectivity, linearity, precision, and accuracy.

Binding of calcium ions to 2,3-dicarboxy derivatives of pectic acid

1986 ◽  
Vol 51 (10) ◽  
pp. 2259-2270 ◽  
Author(s):  
Anna Malovíková ◽  
Rudolf Kohn
Keyword(s):  
Activity Coefficient ◽  
Calcium Ions ◽  
High Selectivity ◽  
Carboxyl Groups ◽  
Free Enthalpy ◽  
Pectic Acid ◽  
Considerable Degradation ◽  
Oxidation Degradation ◽  
Derivatives Of ◽  
Low Activity

Using a two-step oxidation of pectic acid (85% of D-galacturonan in the preparation) a series of 2,3-dicarboxy derivatives (Na+ form) was prepared containing 4.2 to 8.5 mmol of carboxyl groups per gram (COOH g-1). After the centrifugation of the diluted suspensions of the Ca-salts of these polyacids the activity of the calcium counterions (aCa2+) was determined using the metallochromic indicator (tetramethylmurexide) and the activity coefficient γCa2+ was calculated. Using potentiometric titrations of polyacids with potassium and calcium hydroxides the decrease in electrostatic free enthalpy, Δ(Gel/N)KCa, of the cation exchange Ca2+ → 2 K+ was determined. In the course of the oxidation, degradation of the macromolecules took place, characterized by the limit viscosity number [η]. In spite of the considerable degradation, preparations with higher oxidation degrees display a high selectivity in the exchange of cations Ca2+ → 2 K+, similar to that determined recently by us in 2,3-dicarboxy derivatives of starch and amylose. The strong binding of Ca2+ ions to the investigated substances is also documented by very low activity coefficient values, γCa2+, ranging from 0.057 to 0.037.

Halogenated derivatives of boldine with high selectivity for α1A-adrenoceptors in rat cerebral cortex

Life Sciences ◽  
1999 ◽  
Vol 64 (14) ◽  
pp. 1205-1214 ◽  
Author(s):  
Sonia Martinez ◽  
Yolanda Madrero ◽  
Martín Elorriaga ◽  
María-Antonia Noguera ◽  
Bruce Cassels ◽  
...  
Keyword(s):  
Cerebral Cortex ◽  
High Selectivity ◽  
Rat Cerebral Cortex ◽  
Derivatives Of

scholarly journals DEVELOPMENT AND VALIDATION OF UV-VIS SPECTROSCOPIC METHOD OF ASSAY OF CARBAMAZEPINE IN MICROPARTICLES

2019 ◽  
Vol 11 (1) ◽  
pp. 34 ◽  
Author(s):  
Saeid Mezail Mawazi ◽  
Hazrina A. B. Hadi ◽  
Sinan Mohammed Abdullah Al-mahmood ◽  
Abd Almonem Doolaanea
Keyword(s):  
Ethyl Cellulose ◽  
Spectroscopic Method ◽  
Dosage Forms ◽  
Solution Stability ◽  
Distilled Water ◽  
Solvent Evaporation Method ◽  
Accuracy And Precision ◽  
Quantification Analysis ◽  
Precision And Accuracy ◽  
Development And Validation

Objective: This study aimed to develop a new, rapid, robust, effective, inexpensive, and accurate UV-Vis method for the quantification analysis of carbamazepine (CBZ) in the carbamazepine-loaded microparticles.Methods: CBZ was encapsulated in ethyl cellulose microparticles by a solvent evaporation method using polyvinyl alcohol (PVA) as a stabilizer. Methanol was used to dissolve CBZ followed by dilution with distilled water as diluent. CBZ drug, excipients, and microparticles were subjected to specificity, solution stability, linearity, precision and accuracy to confirm and ensure the validity of this method.Results: The results showed no interference from the excipients in the selected wavelength 286 nm. It was exhibited linearity in the range 2-12 μg/ml with R2 = 0.9992. CBZ solution was stable during 24 h. Accuracy and precision were within the accepted limits (100±2%). All results were in accordance to the ICH-Q2 guideline.Conclusion: As a conclusion, CBZ could be quantified from loaded EC microparticles using UV-Vis spectrophotometer at 286 nm. Therefore, this method can be used for the quantification analysis of CBZ in CBZ-loaded microparticles can be utilized also as an alternative method to calculate CBZ in different dosage forms. 

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