An electrochemical molecularly imprinted sensor based on CuBi2O4/rGO@MoS2 nanocomposite and its utilization for highly selective and sensitive for linagliptin assay.

An electrochemical molecularly imprinted sensor based on CuBi2O4/rGO@MoS2 nanocomposite and its utilization for highly selective and sensitive for linagliptin assay

Micellar HPLC-UV method for the simultaneous determination of levodopa, carbidopa and entacapone in pharmaceuticals and human plasma.

Color additives are used in pediatric syrup formulations as an excipient; though not pre-requisite, but pediatric syrup formulations are normally colored. An attempt has been made to measure simultaneously the single drug, acetaminophen (AT), along with the colors, carmoisine (CA), erythrosine (ET), and sunset yellow FCF (SSY) added in it by three derivative spectroscopy methods namely, 1st order, ratio, and differential derivative methods. Moreover, evaluation has been made for the exposure assessment of the colors added as excipient because some colors have been reported to cause allergic reactions and hypersensitivity in children. The present methods provide simple, accurate, and reproducible quantitative determination of the drug, AT, along with the color in synthetic mixtures and commercial drug formulations without any interference. The limit of detection varied from 0.0001–0.31 μg/ml while limit of quantification ranged from 0.002–1.04 μg/ml in all the three methods. The calibration curve of all the three derivative methods exhibited good linear relationship with excellent regression coefficients (0.9986–1.000). Both intra-day and inter-day precisions showed %RSD value less than 2% while the percentage recovery was found between 96.8–103.8%. The sensitivity of the proposed methods is almost comparable to HPLC and thus, can be used for determination of drug AT, and color simultaneously in pharmaceutical formulation on routine basis. The present methods also showed that colors like SSY and ET are saturating more than 50% of acceptable daily intake (ADI) value which is alarming and needs to be considered for modification by regulatory authorities to safeguard the health of children.

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Simultaneous Determination of Acetaminophen and Synthetic Color(s) by Derivative Spectroscopy in Syrup Formulations and Validation by HPLC: Exposure Risk of Colors to Children

Background: The present study is to investigate the neuroprotective effect of ibuprofen by intranasal administration of mucoadhesive microemulsion (MMEI) against inflammation-mediated by dopaminergic neurodegeneration in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) model of Parkinson’s disease (PD).Methods: Ibuprofen-loaded polycarbophil-based MMEI was developed by using response surface methodology (RSM). Ibuprofen with dose of 2.86 mg/kg/day was administered intranasally to male C57BL/6 mice for two consecutive weeks which were pre-treated with four intraperitoneal injections of MPTP (20 mg/kg of body weight) at 2 h intervals. Immunohistochemistry was performed.Results: Optimal MMEI was stable and non-ciliotoxic with 66.29 ± 4.15 nm as average globule size and −20.9 ± 3.98 mV as zeta potential. PDI value and transmission electron microscopy result showed the narrow globule size distribution of MMEI. The result showed that all three independent variables had a significant effect (p < 0.05)...

Design and evaluation of mucoadhesive microemulsion for neuroprotective effect of ibuprofen following intranasal route in the MPTP mice model.

A simple, sensitive, and stability indicating isocratic reverse phase high performance liquid chromatography method has been developed, optimized and validated for the separation and quantification of S-enantiomer in linagliptin (R-enantiomer) drug substance. Enantiomeric separation was achieved on a Cellulose tris(4-chloro-3-methylphenylcarbamate) stationary phase. Mobile phase consists of aqueous diammonium hydrogen phosphate buffer and acetonitrile in the ratio of 35:65 v/v. Isocratic elution was performed at a flow rate of 1.0 mL/min, the column oven temperature was set at 40°C and detection was at 226 nm. The resolution between R and S enantiomers is found to be more than 4.0. The impact of mobile phase composition, pH of buffer and temperature on the resolution has been studied. The detector response is found to be linear over the concentration range of 0.17-1.7 μg/mL. LOD and LOQ levels of S-enantiomer are found to be 0.057 and 0.172 μg/mL respectively. The recovery of S-enantiomer is 99.8% w/w. The proposed method is validated for specificity, precision, linearity, accuracy and robustness.

A new stability indicating reverse phase high performance liquid chromatography method for the determination of enantiomeric purity of a DPP-4 inhibitor drug linagliptin.

Azilsartan is an angiotensin II receptor antagonist used in the treatement of hypertension. U.S. Food and Drug Administration(FDA) approved azilsartan medoxomil for the treatment of high blood pressure in adults. In present work, a simple, sensitive, accurate and economical spectroscopic method has been developed for the estimation of Azilsartan medoxomil in bulk and pharmaceutical dosage forms. An absorption maximum was found to be at 249 nm with the solvent system acetonitrile. The drug follows Beer law in the range of 1-20 µg/ml with correlation coefficient of 0.999. The percentage recovery of Azilsartan medoxomil ranged from 99.9 to 100.3 % in pharmaceutical dosage form. Results of the analysis were validated for accuracy, precision, LOD, LOQ and were found to be satisfactory. The proposed method is simple, rapid and suitabile for the routine quality control analysis.

New Simple UV Spectrophotometric Method for Determination of Azilsartan medoxomil in Bulk and Pharmaceutical dosage forms

A simple and sensitive stability-indicating hptlc assay method for the determination of azilsartan medoxomil

Simple and sensitive Ultra Performance Liquid Chromatography (UPLC) methods were developed, optimized and validated for the determination of 4-Nitro phthalimide, 5-Bromo phthalide and 5-Amino phthalide, 4-Amino phthalimide contents in Citalopram hydrobromide drug substance. All these impurities have been originated from 5-cyanophthalide, a key raw material which is used in the synthetic process of Citalopram. The chromatographic separations were achieved on Acquity UPLC HSS C18 SB, 1.8μm (100 mm x 2.1mm) column maintained at temperature 40°C for the quantification of 4-Nitro phthalimide and 5-Bromo phthalide with a simple mobile phase consisted of 0.01M phosphate buffer at a pH 5.5 and acetonitrile in gradient mode at a flow rate of 0.10 ml/min and monitored at 245nm. Quantification of 5-Amino phthalide and 4-Amino phthalimide were achieved on the same column maintained at temperature 30°C and with same buffer at pH 3.0 and acetonitrile as mobile phase in gradient mode at a flow rate of 0.15 ml/min. These impurities were monitored at 205nm. The analytic methods have been demonstrated through validation experiments. The achieved limit of detection (LOD) values were 1.0, 1.6 ,1.8 and 1.2 ppm, limit of quantification (LOQ) values were 3.0, 5.0, 5.5 and 3.6 ppm and the average accuracy values were 97.9, 102.8, 102.8 & 103.7% for 4-Nitro phthalimide, 5-Bromo phthalide, 5-Amino phthalide and 4-Amino phthalimide respectively.

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Development and validation of UPLC methods for the determination of 4-Nitro phthalimide, 5-Bromo phthalide and 5- Amino phthalide, 4-Amino phthalimide contents in Citalopram hydrobromide drug substance

A sensitive rapid Gas Chromatography with mass spectrometry (GC-MS) method has been developed and validated for the determination of 1-Bromopropane content in Divalproex sodium drug substance. 1-Bromopropane has been considered as a potential genotoxic impurity. The lower level of detection was achieved on fused silica capillary column coated with 100% dimethylpolysiloxane stationary phase with Electron Impact ionization (EI) in Selective Ion Monitoring (SIM) mode. GC runtime was 25min employing programmed temperature with split mode using head-space injection technique. The developed method was validated for specificity, linearity, accuracy and precision. The detection and quantitation limits of 1-Bromopropane obtained were 0.05 μg/g and 0.10 μg/g respectively. The method was found to be linear in the range between 0.10 μg/g and 0.75 μg/g with correlation coefficient 0.9999. The average recovery obtained in Divalproex sodium drug substance was 97.3%. The developed method was found to be rugged for the determination of 1-Bromopropane in divalproex sodium drug substance. The detailed approach of experiments is discussed in the paper

/pdf/quantification-of-potential-genotoxic-impurity-in-divalproex-4jaoxfweba.pdf

N. Sreenivas

Papers

A new stability indicating reverse phase high performance liquid chromatography method for the determination of enantiomeric purity of a DPP-4 inhibitor drug linagliptin.

New Simple UV Spectrophotometric Method for Determination of Azilsartan medoxomil in Bulk and Pharmaceutical dosage forms

A simple and sensitive stability-indicating hptlc assay method for the determination of azilsartan medoxomil

Development and validation of UPLC methods for the determination of 4-Nitro phthalimide, 5-Bromo phthalide and 5- Amino phthalide, 4-Amino phthalimide contents in Citalopram hydrobromide drug substance

Quantification of potential genotoxic impurity in Divalproex sodium drug substance by GC-MS method.