RP‐HPLC Enantioseparation and control of enantiomeric purity of duloxetine using a new chiral reagent and recovery of enantiomers

2021 ◽  
Author(s):  
Renu Vyas ◽  
Ravi Bhushan ◽  
Hariom Nagar ◽  
Aishwarya Sharma
Keyword(s):  
Enantiomeric Purity ◽  
Chiral Reagent ◽  
Rp Hplc ◽  
And Control

scholarly journals Simultaneous Determination of Six Active Compounds in Yixin Badiranjibuya Granules, a Traditional Chinese Medicine, by RP-HPLC-UV Method

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Ning Yu ◽  
ChenHui He ◽  
Gulistan Awuti ◽  
Cheng Zeng ◽  
JianGuo Xing ◽  
...  
Keyword(s):  
Chinese Medicine ◽  
Rosmarinic Acid ◽  
Quality Evaluation ◽  
Scientific Basis ◽  
Determination Method ◽  
Rp Hplc ◽  
And Control ◽  
First Time

In this study, a sensitive, precise, and accurate HPLC-UV method was developed and validated to simultaneously determine the six analytes (luteolin-7-O-β-D-glucuronide, apigenin-7-O-β-D-glucuronide, diosmetin-7-O-β-D-glucuronide, acacetin-7-O-β-D-glucuronide, tilianin, and rosmarinic acid) in Yixin Badiranjibuya Granules, in which five analytes (i.e., luteolin-7-O-β-D-glucuronide, apigenin-7-O-β-D-glucuronide, diosmetin-7-O-β-D-glucuronide, acacetin-7-O-β-D-glucuronide, and rosmarinic acid) were determined for the first time in Yixin Badiranjibuya Granules, the content of tilianin in Yixin Badiranjibuya Granules was reported in other literatures, and the content of tilianin in our work was higher than that of the literature reports. The quality of 11 batch samples from four different manufacturers was evaluated using the proposed determination method. The contents of the six analytes were largely different among samples from various manufacturers. Therefore, this determination method can provide a scientific basis for quality evaluation and control of Yixin Badiranjibuya Granules.

scholarly journals Improved Achiral and Chiral HPLC-UV Analysis of Ruxolitinib in Two Different Drug Formulations

Separations ◽  
2020 ◽  
Vol 7 (3) ◽  
pp. 47
Author(s):  
Alessandro Di Michele ◽  
Aurélie Schoubben ◽  
Ina Varfaj ◽  
Alessandro D’Arpino ◽  
Laura Mercolini ◽  
...  
Keyword(s):  
Stationary Phases ◽  
Retention Factor ◽  
Active Pharmaceutical Ingredient ◽  
Reversed Phase ◽  
Enantiomeric Purity ◽  
Chiral Hplc ◽  
Drug Formulations ◽  
Intermediate Precision ◽  
Rp Hplc ◽  
System Suitability

In this paper, two new reversed-phase (RP) HPLC-UV methods enabling the quantitative achiral and chiral analysis of ruxolitinib in commercial tablets (containing 20 mg of active pharmaceutical ingredient, API) and not commercially available galenic capsules (with 5 mg of API) are described. For the achiral method based on the use of a water/acetonitrile [70:30, v/v; with 0.1% (v) formic acid] eluent, a “research validation” study was performed mostly following the “International Council for Harmonization” guidelines. All the system suitability parameters were within the acceptance criteria: tailing factor, between 1.7 and 2.0; retention factor, 2.2; number of theoretical plates, >9000. The linearity curve showed R2 = 0.99 (Rxv2 = 0.99), while trueness (expressed as recovery) was between 96.3 and 106.3%. Coefficient of variations (CVs) (repeatability: CVw and intermediate precision: CVIP) did not exceed 1.3% and 2.9%, respectively. Moreover, the use of the enantiomeric Whelk-O1 chiral stationary phases operated under similar RP eluent conditions as for the achiral analyses, and the “inverted chirality columns approach (ICCA)” allowed us to establish that the enantiomeric purity of ruxolitinib is retained upon reformulation from tablets to capsules. The two developed methods can allow accurate determinations of ruxolitinib in drug formulations for medical use.

scholarly journals Synthesis of Cyanuric Chloride based Chiral Reagent for RP-HPLC Enantioseparation of (RS)-Propranolol

2022 ◽  
Vol 34 (2) ◽  
pp. 376-382
Author(s):  
H.S. Al-Shehri ◽  
V. Alwera ◽  
K.C. Nilugal ◽  
S. Alwera
Keyword(s):  
Dft Calculations ◽  
Present Method ◽  
Chiral Recognition ◽  
Cyanuric Chloride ◽  
Chiral Reagent ◽  
Rp Hplc ◽  
Validation Parameters ◽  
Ft Ir ◽  
Proline Derivatives ◽  
Derivatives Of

In this work, four cyanuric chloride based chiral reagents were prepared via nucleophile substitution of chlorine atom by L-proline derivatives and characterized by UV, FT-IR, HRMS, NMR and elemental analysis. Racemic propranolol was chosen for the chiral recognition study. The prepared chiral reagents were used in the synthesis of diastereomeric derivatives of (RS)-propranolol, under microwave heating conditions. RP-HPLC was used to separate the prepared diastereomeric derivatives. The effect of varying eluting phase concentrations and sample concentrations was optimized. The DFT calculations were performed using Gaussian 09 Rev A.02 to create the lowest energy optimised structures of diastereomeric derivatives. LOD (0.324 ng mL-1), LOQ (0.972 ng mL-1), calibration range (0.02-2.0 mg mL-1), correlation-coefficient (0.999), and recovery were the validation parameters for the present method (99.09 and 99.81 % for inter-day assay and 98.47 and 99.72 % for intra-day assay).

Control of Metal Alloy Oxidation with Electric Fields

1973 ◽  
Vol 31 ◽  
pp. 164-165
Author(s):  
R. R. Dils ◽  
P. S. Follansbee
Keyword(s):  
Electric Fields ◽  
Oxidation Process ◽  
Base Alloy ◽  
Oxide Surface ◽  
Platinum Electrodes ◽  
Insulating Layer ◽  
Iron Base Alloy ◽  
Alloy Oxidation ◽  
Aluminum Oxide Layer ◽  
And Control

Electric fields have been applied across oxides growing on a high temperature alloy and control of the oxidation of the material has been demonstrated. At present, three-fold increases in the oxidation rate have been measured in accelerating fields and the oxidation process has been completely stopped in a retarding field.The experiments have been conducted with an iron-base alloy, Pe 25Cr 5A1 0.1Y, although, in principle, any alloy capable of forming an adherent aluminum oxide layer during oxidation can be used. A specimen is polished and oxidized to produce a thin, uniform insulating layer on one surface. Three platinum electrodes are sputtered on the oxide surface and the specimen is reoxidized.

Evidence for a Blood Ganglion Barrier in the Superior Cervical Ganglion of the Rat

1982 ◽  
Vol 40 ◽  
pp. 204-204
Author(s):  
D. M. DePace
Keyword(s):  
Blood Vessels ◽  
Superior Cervical Ganglion ◽  
Peripheral Nerves ◽  
Time Schedule ◽  
Transmission Electron ◽  
Cervical Ganglion ◽  
The Central Nervous System ◽  
Cervical Ganglia ◽  
Capillary Circulation ◽  
And Control

The majority of blood vessels in the superior cervical ganglion possess a continuous endothelium with tight junctions. These same features have been associated with the blood brain barrier of the central nervous system and peripheral nerves. These vessels may perform a barrier function between the capillary circulation and the superior cervical ganglion. The permeability of the blood vessels in the superior cervical ganglion of the rat was tested by intravenous injection of horseradish peroxidase (HRP). Three experimental groups of four animals each were given intravenous HRP (Sigma Type II) in a dosage of.08 to.15 mg/gm body weight in.5 ml of.85% saline. The animals were sacrificed at five, ten or 15 minutes following administration of the tracer. Superior cervical ganglia were quickly removed and fixed by immersion in 2.5% glutaraldehyde in Sorenson's.1M phosphate buffer, pH 7.4. Three control animals received,5ml of saline without HRP. These were sacrificed on the same time schedule. Tissues from experimental and control animals were reacted for peroxidase activity and then processed for routine transmission electron microscopy.

Effects of renovascular hypertension on rat adrenal zona glomerulosa

1978 ◽  
Vol 36 (2) ◽  
pp. 582-583
Author(s):  
G. Mazzocchi ◽  
P. Rebuffat ◽  
C. Robba ◽  
P. Vassanelli ◽  
G. G. Nussdorfer
Keyword(s):  
Renovascular Hypertension ◽  
Left Kidney ◽  
Renin Angiotensin System ◽  
Plasma Renin ◽  
Zona Glomerulosa ◽  
Ultrastructural Changes ◽  
Albino Rats ◽  
Left Renal Artery ◽  
Angiotensin System ◽  
And Control

It is well known that the rat adrenal zona glomerulosa steroidogenic activity is controlled by the renin-angiotensin system. The ultrastructural changes in the rat zona glomerulosa cells induced by renovascular hypertension were described previously, but as far as we are aware no correlated biochemical and morphometric investigations were performed.Twenty adult male albino rats were divided into 2 experimental groups. One group was subjected to restriction of blood flow to the left kidney by the application of a silver clip about the left renal artery. The other group was sham-operated and served as a control. Renovascular hypertension developed in about 10 days: sistolic blood pressure averaged 165 ± 6. 4 mmHg, whereas it was about 110 ± 3. 8 mmHg in the control animals. The hypertensive and control rats were sacrificed 20 days after the operation. The blood was collected and plasma renin activity was determined by radioimmunological methods. The aldosterone concentration was radioimmunologically assayed both in the plasma and in the homogenate of the left capsular adrenal gland.

X-Ray Replication of Submicrometer Linewidth Patterns

1977 ◽  
Vol 35 ◽  
pp. 136-137
Author(s):  
Henry I. Smith ◽  
D.C. Flanders
Keyword(s):  
Electron Beam Lithography ◽  
Cross Sectional ◽  
X Ray ◽  
Electron Backscattering ◽  
Spatial Frequencies ◽  
Cross Sectional Profile ◽  
Carbon Foils ◽  
Sectional Profile ◽  
And Control ◽  
Soft Radiation

Scanning electron beam lithography has been used for a number of years to write submicrometer linewidth patterns in radiation sensitive films (resist films) on substrates. On semi-infinite substrates, electron backscattering severely limits the exposure latitude and control of cross-sectional profile for patterns having fundamental spatial frequencies below about 4000 Å(l),Recently, STEM'S have been used to write patterns with linewidths below 100 Å. To avoid the detrimental effects of electron backscattering however, the substrates had to be carbon foils about 100 Å thick (2,3). X-ray lithography using the very soft radiation in the range 10 - 50 Å avoids the problem of backscattering and thus permits one to replicate on semi-infinite substrates patterns with linewidths of the order of 1000 Å and less, and in addition provides means for controlling cross-sectional profiles. X-radiation in the range 4-10 Å on the other hand is appropriate for replicating patterns in the linewidth range above about 3000 Å, and thus is most appropriate for microelectronic applications (4 - 6).

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