211 REVERSED-PHASE HIGH-PERFORMANCE LIQUID CHROMATOGRAPHY AS A TOOL TO ELUCIDATE THE BIOLOGICAL ACTIVITY OF COMMERCIAL EQUINE CHORIONIC GONADOTROPIN (eCG)

2014 ◽  
Vol 26 (1) ◽  
pp. 219
Author(s):  
R. H. Alvarez ◽  
B. E. Almeida ◽  
M. T. C. P. Ribela ◽  
F. L. N. Natal ◽  
A. J. F. Melo ◽  
...  

Superovulation in ruminants can be induced with a single injection of equine chorionic gonadotropin (eCG). However, ovarian response is sometimes lower than expected because of, among other factors, the source of eCG used. This study aimed at establishing the physical-chemical profile of commercial eCG, in order to find differences which can be related to their biological activity. Four different commercial eCG products for veterinary use (A, B, C, D) and one eCG chemical reagent from Sigma (St. Louis, MO, USA), here used as reference preparation, were analysed by reversed-phase high-performance liquid chromatography (RP-HPLC) using a C4-Grace Vydac 214 TP 54-column (25 cm × 4.6 mm I.D.), with UV detection at 220 nm. All eCG preparations presented at least three peaks with retention times (tR) of ~27(I), 34(II), and 36(III) minutes, with a peak at tR = 27 min common to A, C, D, and Sigma eCG, whereas preparation B did not present this peak. A bioassay test was carried with all of these preparations. Immature 21- to 25-day-old Wistar female rats received the equivalent to 10 IU of eCG of each one of these preparations. Autopsy was performed 48 h later and ovaries were removed and weighed. The average ovarian weight for preparations A, C, D, and Sigma were ~0.0795 ± 0.0107 g, whereas preparation B was 0.035 ± 0.007 g (P < 0.01). Preparation B was not different from saline (0.034 ± 0.002 g). In order to establish which one of these three peaks presented the highest biological activity, a mass equivalent to 10 IU of eCG from peaks I, II, and III of Sigma and of product A were studied. The average ovarian weight of animals injected with material from peak II and III (~0.0285 ± 0.003 g) were similar to that of the control whereas peak I produced ovarian weights of 0.059 ± 0.007 g and 0.075 ± 0.010 g for Sigma and product A, respectively (P < 0.01). These results suggest that the lack of ovarian response to eCG treatments can be related to differences in the physical-chemical profile of commercial eCG products and that RP-HPLC is a fast and reliable tool for detecting these differences. Supported by FAPESP (Grant 11/13096-0).

1985 ◽  
Vol 65 (2) ◽  
pp. 285-298 ◽  
Author(s):  
J. E. KRUGER ◽  
B. A. MARCHYLO

Chromatographic conditions were optimized and three commercially available columns were evaluated for separation of alcohol-soluble storage proteins of Neepawa wheat using reversed-phase high-performance liquid chromatography (RP-HPLC). Optimal separation was achieved using an extracting solution of 50% 1-propanol, 1% acetic acid, and 4% dithiothreitol and an HPLC elution time of 105 min at a flow rate of 1.0 mL/min. HPLC columns evaluated (SynChropak RP-P, Ultrapore RPSC and Aquapore RP-300) varied in selectivity and resolution. The column providing the greatest versatility was Aquapore RP-300 available in cartridge form. Sodium dodecyl sulfate gradient-gel electrophoresis analysis of protein peaks resolved by RP-HPLC indicated that many of the eluted peaks contained more than one protein species. Chromatographic protein patterns obtained for Neepawa wheat grown at different locations and in different years were qualitatively the same.Key words: Protein, high-performance liquid chromatography, wheat


2010 ◽  
Vol 2 (7) ◽  
pp. 142-147
Author(s):  
O. Amos Abolaji ◽  
M. Ubana Eteng ◽  
E. Patrick Ebong ◽  
Andi Brisibe ◽  
Ahmed Shakil ◽  
...  

Author(s):  
Muhammad Fawad Rasool ◽  
Umbreen Fatima Qureshi ◽  
Nazar Muhammad Ranjha ◽  
Imran Imran ◽  
Mouqadus Un Nisa ◽  
...  

AbstractTh accurate rapid, simple and selective reversed phase high performance liquid chromatography (RP-HPLC) has been established and validated for the determination of captopril (CAP). Chromatographic separation was accomplished using prepacked ODSI C18 column (250 mm × 4.6 mm with 5 μm particle size) in isocratic mode, with mobile phase consisting of water: acetonitrile (60:40 v/v), pH adjusted to 2.5 by using 85% orthophosphoric acid at a flow rate of 1 mL/min and UV detection was performed at 203 nm. RP-HPLC method used for the analysis of CAP in mobile phase and rabbit plasma was established and validated as per ICH-guidelines. It was carried out on a well-defined chromatographic peak of CAP was established with a retention time of 4.9 min and tailing factor of 1.871. The liquid–liquid extraction method was used for extraction of CAP from the plasma. Excellent linearity (R2 = 0.999) was shown over range 3.125–100 µg/mL with mean percentage recoveries ranges from 97 to 100.6%. Parameters of precision and accuracy of the developed method meet the established criteria. Intra and inter-day precision (% relative standard deviation) study was also performed which was less than 2% which indicate good reproducibility of the method. The limit of detection (LOD) and quantification for the CAP in plasma were 3.10 and 9.13 ng/mL respectively. The method was suitably validated and successfully applied to the determination of CAP in rabbit plasma samples.


Author(s):  
PULAGURTHA BHASKARARAO ◽  
GOWRI SANKAR DANNANA

Objective: Noscof tablet is a fixed dosage combination formulation having diphenhydramine (DH), ephedrine (ED), noscapine (NP), and glycerol glycolate (GG). A sensitive, selective, accurate, precise, and stability-indicating reversed-phase high-performance liquid chromatography (RP-HPLC) method with photodiode array detection has been developed and validated for simultaneous analysis of DH, ED, NP, and GG in bulk drug and Noscof tablets. Methods: Reversed-phase chromatographic separation and analysis of DH, ED, NP, and GG were done on an Altima C18 column with 0.01 M KH2PO4 buffer (pH 3.5) and acetonitrile (50:50%, v/v) as mobile phase at 0.8 ml/min flow rate in isocratic mode. Detection was performed at 260 nm. The method was validated in harmony with International Conference on Harmonization (ICH) guidelines. The tablet sample solution was subjected to diverse stress conditions using ICH strategy such as hydrolytic degradation (neutral - with distilled water, alkaline - with 2 N NaOH, and acidic - with 2 N HCl), oxidation (with 10% H2O2), photodegradation (exposing to UV light), and dry heat degradation (exposing to 105°C). Results: Using the above stated chromatographic conditions, sharp peaks were obtained for ED, NP, DH, and GG with retention time of 3.272 min, 4.098 min, 5.467 min, and 6.783 min, respectively. Good regression coefficient values were obtained in the range of 2–12 μg/ml for ED, 3.75–22.5 μg/ml for NP, 3.125–18.75 μg/ml for DH, and 25–150 μg/ml for GG. The quantification limits were 0.181 μg/ml, 0.187 μg/ml, 0.246 μg/ml, and 1.114 μg/ml for ED, NP, DH, and GG, respectively. The values of validation parameters are within the acceptance limits given by ICH. The ED, NP, DH, and GG showed more percent of degradation in acid condition and less percent of degradation in the neutral condition. The peaks of degradants did not interfere with the peaks of analytes. ED, NP, DH, and GG were assessed with a good percentage of the assay (near to 100%) and low percent relative standard deviation (<2%) in Noscof tablets using the proposed method. Conclusion: The stability indicating RP-HPLC method developed was suitable for quantifying ED, NP, DH, and GG simultaneously in bulk as well as in tablet formulation.


Author(s):  
Bijithra Cholaraja ◽  
Shanmugasundaram P ◽  
Ragan G ◽  
Sankar Ask ◽  
Sumithra M

ABSTRACTObjective: To development and validation of a reversed-phase high-performance liquid chromatography (RP-HPLC) for the determination of modafinilin bulk and pharmaceutical dosage forms.Methods: A simple, precise, rapid, and accurate RP-HPLC method was developed for the estimation of modafinil in bulk and pharmaceutical dosageforms. Xterra RP 18 (250 mm × 4.6 mm, 5 µ particle size) with a mobile phase consisting of methanol:water 70:30 V/V was used. The flow rate1.0 ml/min and the effluents were monitored at 260 nm. The retention time and recovery time was 12 minutes. The detector response was linear inthe concentration of 10-50 µg/ml. The respective linear regression equation being Y=452.1x+65237. The limit of detection and limit of quantificationwere 4.547 and 1.377 mcg, respectively. The method was validated by determining its accuracy, precision, and system suitability.Result: The objective of the present work is to develop simple, precise, and reliable HPLC method for the analysis of modafinil in bulk andpharmaceutical dosage forms. This is achieved using the most commonly employed Xterra RP 18 (250 mm × 4.6 mm, 5 μ particle size) columndetection at 260 nm. The present method was validated according to ICH guidelines.Conclusion: In this study, a simple, fast and reliable HPLC method was developed and validated for the determination of modafinil in pharmaceuticalformulations.Keywords: Modafinil, Reversed-phase high-performance liquid chromatography, Estimation, ICH guidelines, Tablets. 


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