Pub Date : 2021-09-03DOI: 10.2174/2213240608666210903143432
Kumar Janakiraman, Venkateshwaran Krishnaswami, Vaidevi Sethuraman, V. Rajendran, R. Kandasamy
To develop an RP-HPLC method for the simultaneous estimation of methotrexate (MTX) and minocycline (MNC). Different HPLC methods were reported for the estimation of MTX/MNC individually, but there is no report for the simultaneous estimation of both MTX and MNC in a simple method. The objective of the developed method is to utilize the method for the estimation of MTX/MNC in different pharmaceutical formulations and in biological fluids. An HPLC method for the estimation of methotrexate (MTX) and minocycline (MNC) relevance to the evaluation of nanoparticulate formulations has been developed and validated. Chromatographic estimation was achieved using the mobile phase composition of sodium acetate buffer and acetonitrile (70:30% v/v) at pH 4.0 at a flow rate of 0.2 mL/min at 307 nm. The calibration curve for MTX and MNC was found to be linear at nanogram (5 to 25 ng.mL-1) and microgram (5 to 25 μg.mL-1) levels at a correlation coefficient range of 0.98 to 0.99 for both MTX/MNC. The lower limit of detection and limit of quantification were found to be 0.026 ng.mL-1 and 0.079 ng.mL-1 for MTX and MNC, respectively. The percentage relative standard deviation for validation parameters of both drugs was found to be less than 6.5%. The amount of MTX and MNC present within the nanoparticles was found to be MTX (0.84 mg/mL) and MNC (0.61 mg/mL). The in vitro release showed an immediate release pattern for MTX (64.95±2.08%) and MNC (90.90±1.78%) within 12 h. The developed analytical method for the simultaneous estimation of MTX and MNC was found to be simple, affordable, dynamic, low cost, rapid and easy to perform with good repeatability. This method is also time consuming, since the peaks were obtained within a moderate analysis time.
{"title":"Liquid Chromatographic analysis of Methotrexate and Minocycline- Relevance to the determination in Plasma/Nanoparticulate formulations","authors":"Kumar Janakiraman, Venkateshwaran Krishnaswami, Vaidevi Sethuraman, V. Rajendran, R. Kandasamy","doi":"10.2174/2213240608666210903143432","DOIUrl":"https://doi.org/10.2174/2213240608666210903143432","url":null,"abstract":"\u0000\u0000To develop an RP-HPLC method for the simultaneous estimation of methotrexate (MTX) and minocycline (MNC).\u0000\u0000\u0000\u0000\u0000Different HPLC methods were reported for the estimation of MTX/MNC individually, but there is no report for the simultaneous estimation of both MTX and MNC in a simple method.\u0000\u0000\u0000\u0000\u0000The objective of the developed method is to utilize the method for the estimation of MTX/MNC in different pharmaceutical formulations and in biological fluids.\u0000\u0000\u0000\u0000\u0000An HPLC method for the estimation of methotrexate (MTX) and minocycline (MNC) relevance to the evaluation of nanoparticulate formulations has been developed and validated. Chromatographic estimation was achieved using the mobile phase composition of sodium acetate buffer and acetonitrile (70:30% v/v) at pH 4.0 at a flow rate of 0.2 mL/min at 307 nm.\u0000\u0000\u0000\u0000\u0000 The calibration curve for MTX and MNC was found to be linear at nanogram (5 to 25 ng.mL-1) and microgram (5 to 25 μg.mL-1) levels at a correlation coefficient range of 0.98 to 0.99 for both MTX/MNC. The lower limit of detection and limit of quantification were found to be 0.026 ng.mL-1 and 0.079 ng.mL-1 for MTX and MNC, respectively. The percentage relative standard deviation for validation parameters of both drugs was found to be less than 6.5%. The amount of MTX and MNC present within the nanoparticles was found to be MTX (0.84 mg/mL) and MNC (0.61 mg/mL). The in vitro release showed an immediate release pattern for MTX (64.95±2.08%) and MNC (90.90±1.78%) within 12 h. \u0000\u0000\u0000\u0000\u0000 The developed analytical method for the simultaneous estimation of MTX and MNC was found to be simple, affordable, dynamic, low cost, rapid and easy to perform with good repeatability. This method is also time consuming, since the peaks were obtained within a moderate analysis time. \u0000\u0000","PeriodicalId":10826,"journal":{"name":"Current chromatography","volume":"11 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75889738","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-08-13DOI: 10.2174/2213240608666210813105715
Nayan S. Gadhari, J. Gholave, S. Patil, A. R. Patil, K. Shelke, Viswanath R. Patil, Sharad S. Upadhyay
To address the separation of interfering potential impurities associated with the drug is always a daunting task. We present the method validation and quantitative determination of sulfadoxine (SUL), an anti-malarial drug with most important interfering impurities present pharmaceutical dosages and in bulk samples using HPLC-UV method. The UV detection was obtained at 270 nm and SUL is separated on Sunfire C18 (25 cm x 4.6 mm x 5 µ m) column at 45°C with flow rate of 1.0 mL/min in a mobile phase (CH3COOH:CH3CN). The stress testing (acidic/basic/oxidative) was performed using HPLC for SUL and its impurities showing the highly efficient separation peaks between degradant and drug product. The developed method was found to be highly accurate and sensitive in regulation with ICH guidelines. Also, it was found to be free from interference from degradation products which allows the stability indicating capability of developed HPLC-UV method for SUL for validation in bulk drugs. The main advantages of the present method; (a) Separation achieved in 30 minutes, (b) MS compatible mobile phase renders this developed method can be directly adapted to LC-MS without any major modifications in near future, and (c) separation of twelve impurities on Sunfire C18 column. The CFs (correction factors) had been calculated for all the impurities. It was found to be 1.6 (IMP IX), 1.70 (IMP XI) and in between 0.8-1.3 for all other impurities. The LOD of the developed method for all the analytes were in the range of 0.05 to 0.11 μg/mL and the LOQ values were in the range of 0.17 to 0.36 μg/mL.
解决与药物相关的干扰性潜在杂质的分离一直是一项艰巨的任务。采用高效液相色谱-紫外分光光度法对磺胺多辛(suladoxine, SUL)进行了定量测定。磺胺多辛是一种抗疟疾药物，其主要干扰杂质存在于药物剂量和样品中。在270 nm处进行紫外检测，在45°C，流动相(CH3COOH:CH3CN)流速为1.0 mL/min的Sunfire C18 (25 cm × 4.6 mm × 5µm)柱上分离SUL。采用高效液相色谱法对SUL及其杂质进行了酸性/碱性/氧化应激测试，发现降解物与药品之间存在高效分离峰。所开发的方法在符合ICH指南的监管中具有高度的准确性和敏感性。此外，发现它不受降解产物的干扰，这使得所开发的HPLC-UV法用于原料药验证的稳定性表明能力。本方法的主要优点;(a)在30分钟内实现分离，(b) MS兼容流动相使得该方法可以直接适用于LC-MS，在不久的将来不会有任何重大的修改，(c)在Sunfire C18柱上分离了12种杂质。计算了所有杂质的校正系数。该方法的定量限范围为0.05 ~ 0.11 μg/mL，定量限范围为0.17 ~ 0.36 μg/mL。
{"title":"High Performance HPLC-UV Method Development and Validation for Sulfadoxine from its Potential Interfering Impurities","authors":"Nayan S. Gadhari, J. Gholave, S. Patil, A. R. Patil, K. Shelke, Viswanath R. Patil, Sharad S. Upadhyay","doi":"10.2174/2213240608666210813105715","DOIUrl":"https://doi.org/10.2174/2213240608666210813105715","url":null,"abstract":"\u0000\u0000To address the separation of interfering potential impurities associated with the drug is always a daunting task. We present the method validation and quantitative determination of sulfadoxine (SUL), an anti-malarial drug with most important interfering impurities present pharmaceutical dosages and in bulk samples using HPLC-UV method. \u0000\u0000\u0000\u0000The UV detection was obtained at 270 nm and SUL is separated on Sunfire C18 (25 cm x 4.6 mm x 5 µ m) column at 45°C with flow rate of 1.0 mL/min in a mobile phase (CH3COOH:CH3CN). The stress testing (acidic/basic/oxidative) was performed using HPLC for SUL and its impurities showing the highly efficient separation peaks between degradant and drug product. \u0000\u0000\u0000\u0000The developed method was found to be highly accurate and sensitive in regulation with ICH guidelines. Also, it was found to be free from interference from degradation products which allows the stability indicating capability of developed HPLC-UV method for SUL for validation in bulk drugs.\u0000\u0000\u0000\u0000The main advantages of the present method; (a) Separation achieved in 30 minutes, (b) MS compatible mobile phase renders this developed method can be directly adapted to LC-MS without any major modifications in near future, and (c) separation of twelve impurities on Sunfire C18 column. The CFs (correction factors) had been calculated for all the impurities. It was found to be 1.6 (IMP IX), 1.70 (IMP XI) and in between 0.8-1.3 for all other impurities. The LOD of the developed method for all the analytes were in the range of 0.05 to 0.11 μg/mL and the LOQ values were in the range of 0.17 to 0.36 μg/mL.\u0000","PeriodicalId":10826,"journal":{"name":"Current chromatography","volume":"22 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-08-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80048689","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-08-11DOI: 10.2174/2213240608666210811123051
Miriam Nayeli Morales-Barragán, M. C. Romero-Méndez, R. C. Milán-Segovia, J. G. Rodríguez-Rivera, M. A. Aguilar-Torres, S. Romano-Moreno
Metformin is the first-line drug to enhance glycemic control of type 2 diabetes mellitus (DM2) patients. Some reported methods to determine plasma metformin by HPLC-UV are not sensitive enough. Other methods require long extraction processes. The objective of this study was to develop and validate a simple and rapid analytical method to determine plasma metformin by HPLC-UV for application in a population pharmacokinetic study. Analyte was extracted from plasma by a simple protein precipitation technique using trichloroacetic acid (15%, w/v) as the precipitating agent. Plasma samples were analyzed using a C18 column (3.0 x 150 mm, 3.5 µm) under isocratic elution with 30 mM sodium hexansulfonate (pH 5) and acetonitrile (97: 3, v/v). The limit of quantification (LOQ) was 0.1 µg mL-1 and the calibration curve was linear up to 4 µg mL-1 with a correlation coefficient >0.99. The mean recovery for metformin using this extraction procedure was 84.4 - 86.6%. The intra- and inter-day coefficients of variation and percent error values of the assayed method were <0% and <15% for LOQ and QCs, respectively. Metformin was stable in plasma samples by subjecting it to three freeze-thaw cycles and storing it up to 60 days at -80°C. This method was applied to determine plasma metformin concentrations in patients with type 2 diabetes mellitus treated with this drug. The HPLC-UV method developed is selective, accurate and precise for the quantification of metformin in plasma samples. Since sample, processing is fast and simple, in addition to being applicable in pharmacokinetic studies.
{"title":"Development and Validation of a Simple Micromethod for the Determination of Metformin in Plasma by HPLC-UV for application in pharmacokinetics studies","authors":"Miriam Nayeli Morales-Barragán, M. C. Romero-Méndez, R. C. Milán-Segovia, J. G. Rodríguez-Rivera, M. A. Aguilar-Torres, S. Romano-Moreno","doi":"10.2174/2213240608666210811123051","DOIUrl":"https://doi.org/10.2174/2213240608666210811123051","url":null,"abstract":"\u0000\u0000Metformin is the first-line drug to enhance glycemic control of type 2 diabetes mellitus (DM2) patients. Some reported methods to determine plasma metformin by HPLC-UV are not sensitive enough. Other methods require long extraction processes. \u0000\u0000\u0000\u0000The objective of this study was to develop and validate a simple and rapid analytical method to determine plasma metformin by HPLC-UV for application in a population pharmacokinetic study.\u0000\u0000\u0000\u0000\u0000 Analyte was extracted from plasma by a simple protein precipitation technique using trichloroacetic acid (15%, w/v) as the precipitating agent. Plasma samples were analyzed using a C18 column (3.0 x 150 mm, 3.5 µm) under isocratic elution with 30 mM sodium hexansulfonate (pH 5) and acetonitrile (97: 3, v/v). \u0000\u0000\u0000\u0000The limit of quantification (LOQ) was 0.1 µg mL-1 and the calibration curve was linear up to 4 µg mL-1 with a correlation coefficient >0.99. The mean recovery for metformin using this extraction procedure was 84.4 - 86.6%. The intra- and inter-day coefficients of variation and percent error values of the assayed method were <0% and <15% for LOQ and QCs, respectively. Metformin was stable in plasma samples by subjecting it to three freeze-thaw cycles and storing it up to 60 days at -80°C. This method was applied to determine plasma metformin concentrations in patients with type 2 diabetes mellitus treated with this drug.\u0000\u0000\u0000\u0000The HPLC-UV method developed is selective, accurate and precise for the quantification of metformin in plasma samples. Since sample, processing is fast and simple, in addition to being applicable in pharmacokinetic studies.\u0000","PeriodicalId":10826,"journal":{"name":"Current chromatography","volume":"24 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-08-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80984630","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-12-29DOI: 10.2174/2213240607999200813194349
B. Antony, M. Benny, Binu T. Kuruvilla, Anu P Sebastian, Anu Aravind Aravindakshan Pillai, Biji Joseph, Sheeja Edappattu Chandran
Withanolide glycosides in Ashwagandha (Withania somnifera), are important metabolites attributed with widely acclaimed therapeutic potential for which validated methods for quantitative determination are limited. The primary objective was to develop and validate a Reversed-Phase High Performance Liquid Chromatography (RP-HPLC) method for simultaneous quantification of total withanolide glycosides (WG), withanoside IV and withaferin A present in ashwagandha extract.The study also aimed to identify various other constituents present in the extract. Aqueous methanol extract (AME) of Ashwagandha was prepared and fractionated into two viz. flavonoid rich fraction (FF) and withanolide rich fraction (WF). RP-HPLC method was developed and validated for the estimation of total WG in ashwagandha extract according to ICH guidelines. Preparative HPLC based purification of major compounds from WF fraction was carried out and constituents were identified using spectroscopic techniques. HPLC chemical profiling of WF before and after acid hydrolysis under controlled conditions was carried out to further confirm the glycosidic compounds. The RP-HPLC method gave a precise differentiation of flavonoids, withanolides and WG present in ashwagandha extract. The method demonstrated good reliability and sensitivity, and can be conveniently used for the quantification of total WG, withanoside IV and withaferin A present in ashwagandha extracts. According to this method, a purified fraction (WF) prepared from roots and leaves of Ashwagandha comprise 35% of total WG, 3.27% of withanoside IV and 2.40% of Withaferin A. The method was also applied to different products prepared from Ashwagandha with total withanolide glycosides ranged from 1.5% to 60%, and the results were found to be reproducible. Identification of the individual chemical constituents as well as the acid hydrolytic pattern of the extract further supported the reliability of the developed method for the quantitative determination of total WG. This study also reported a new withanolide glycoside named, cilistol V-6’-O-glucoside (Aswanoside) along with some other known withanolide glycosides. A Reversed-Phase High Performance Liquid Chromatography (RP-HPLC) method was developed and validated for the quantitative determination of total WG, withanoside IV and withaferin A present in ashwagandha extract according to ICH guidelines. This study also reported a new withanolide glycoside named, cilistol V-6’-O-glucoside (Aswanoside) along with some other known WG.
{"title":"Development and validation of an RP-HPLC method for the simultaneous determination of total withanolide glycosides and Withaferin A in Withania somnifera (Ashwagandha)","authors":"B. Antony, M. Benny, Binu T. Kuruvilla, Anu P Sebastian, Anu Aravind Aravindakshan Pillai, Biji Joseph, Sheeja Edappattu Chandran","doi":"10.2174/2213240607999200813194349","DOIUrl":"https://doi.org/10.2174/2213240607999200813194349","url":null,"abstract":"\u0000\u0000Withanolide glycosides in Ashwagandha (Withania somnifera), are important\u0000metabolites attributed with widely acclaimed therapeutic potential for which validated methods\u0000for quantitative determination are limited.\u0000\u0000\u0000\u0000The primary objective was to develop and validate a Reversed-Phase High Performance\u0000Liquid Chromatography (RP-HPLC) method for simultaneous quantification of total withanolide\u0000glycosides (WG), withanoside IV and withaferin A present in ashwagandha extract.The study also\u0000aimed to identify various other constituents present in the extract.\u0000\u0000\u0000\u0000Aqueous methanol extract (AME) of Ashwagandha was prepared and fractionated\u0000into two viz. flavonoid rich fraction (FF) and withanolide rich fraction (WF). RP-HPLC\u0000method was developed and validated for the estimation of total WG in ashwagandha extract according\u0000to ICH guidelines. Preparative HPLC based purification of major compounds from WF fraction\u0000was carried out and constituents were identified using spectroscopic techniques. HPLC chemical\u0000profiling of WF before and after acid hydrolysis under controlled conditions was carried out to further\u0000confirm the glycosidic compounds.\u0000\u0000\u0000\u0000The RP-HPLC method gave a precise differentiation of flavonoids, withanolides\u0000and WG present in ashwagandha extract. The method demonstrated good reliability and\u0000sensitivity, and can be conveniently used for the quantification of total WG, withanoside IV and\u0000withaferin A present in ashwagandha extracts. According to this method, a purified fraction (WF)\u0000prepared from roots and leaves of Ashwagandha comprise 35% of total WG, 3.27% of withanoside\u0000IV and 2.40% of Withaferin A. The method was also applied to different products prepared from\u0000Ashwagandha with total withanolide glycosides ranged from 1.5% to 60%, and the results were\u0000found to be reproducible. Identification of the individual chemical constituents as well as the acid\u0000hydrolytic pattern of the extract further supported the reliability of the developed method for the\u0000quantitative determination of total WG. This study also reported a new withanolide glycoside\u0000named, cilistol V-6’-O-glucoside (Aswanoside) along with some other known withanolide glycosides.\u0000\u0000\u0000\u0000A Reversed-Phase High Performance Liquid Chromatography (RP-HPLC) method\u0000was developed and validated for the quantitative determination of total WG, withanoside IV and\u0000withaferin A present in ashwagandha extract according to ICH guidelines. This study also reported\u0000a new withanolide glycoside named, cilistol V-6’-O-glucoside (Aswanoside) along with some\u0000other known WG.\u0000","PeriodicalId":10826,"journal":{"name":"Current chromatography","volume":"11 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-12-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88591705","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-10-29DOI: 10.2174/2213240607999201029204934
Ayesha Akhtar, Shivakumar Arumugam, S. Alam
Protein A affinity chromatography is often employed as the most crucial purification step for monoclonal antibodies to achieve high yield with purity and throughput requirements. Protein A, also known as Staphylococcal protein A (SPA) is found in the cell wall of the bacteria staphylococcus aureus. It is one of the first discovered immunoglobulin binding molecules and has been extensively studied since the past few decades. The efficiency of Protein A affinity chromatography to purify a recombinant monoclonal antibody in a cell culture sample has been evaluated, which removes 99.0% of feed stream impurities. We have systematically evaluated the purification performance by using a battery of analytical methods SDS-PAGE (non-reduced and reduced sample), Cation Exchange Chromatography (CEX), Size-exclusion chromatography (SEC), and Reversed phased-Reduced Chromatography for a CHO-derived monoclonal antibody. The analytical test was conducted to determine the impurity parameter, Host Cell Contaminating Proteins (HCP). It was evaluated to be 0.015ng/ml after the purification step; while initially, it was found to be 24.431ng/ml. The tests showed a distinct decrease in the level of different impurities after the chromatography step. It can be concluded that Protein A chromatography is an efficient step in the purification of monoclonal antibodies.
{"title":"Evaluation of the Efficiency of Protein A Affinity Chromatography to Purify a Monoclonal Antibody for Cancer Treatment and its Purity Analysis","authors":"Ayesha Akhtar, Shivakumar Arumugam, S. Alam","doi":"10.2174/2213240607999201029204934","DOIUrl":"https://doi.org/10.2174/2213240607999201029204934","url":null,"abstract":"\u0000\u0000Protein A affinity chromatography is often employed as the most crucial\u0000purification step for monoclonal antibodies to achieve high yield with purity and throughput requirements.\u0000\u0000\u0000\u0000Protein A, also known as Staphylococcal protein A (SPA) is found in the cell wall of\u0000the bacteria staphylococcus aureus. It is one of the first discovered immunoglobulin binding\u0000molecules and has been extensively studied since the past few decades. The efficiency of Protein A\u0000affinity chromatography to purify a recombinant monoclonal antibody in a cell culture sample has\u0000been evaluated, which removes 99.0% of feed stream impurities.\u0000\u0000\u0000\u0000We have systematically evaluated the purification performance by using a\u0000battery of analytical methods SDS-PAGE (non-reduced and reduced sample), Cation Exchange\u0000Chromatography (CEX), Size-exclusion chromatography (SEC), and Reversed phased-Reduced\u0000Chromatography for a CHO-derived monoclonal antibody.\u0000\u0000\u0000\u0000The analytical test was conducted to determine the impurity parameter,\u0000Host Cell Contaminating Proteins (HCP). It was evaluated to be 0.015ng/ml after the purification\u0000step; while initially, it was found to be 24.431ng/ml.\u0000\u0000\u0000\u0000The tests showed a distinct decrease in the level of different impurities after the chromatography\u0000step. It can be concluded that Protein A chromatography is an efficient step in the purification\u0000of monoclonal antibodies.\u0000","PeriodicalId":10826,"journal":{"name":"Current chromatography","volume":"61 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78997741","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-10-01DOI: 10.2174/2213240606666190912161221
Yoichiro Ito
Background: Motion of the two mutually immiscible liquids in hydrodynamic countercurrent chromatographic systems is speculated based on the observation of their behavior in a closed coiled tube rotating in unit gravity.
Materials and methods: The experiment revealed an up and down pattern of four stages of two-phase volume ratio occupied at the head end of the coil according to the rotation speed. These two-phase behaviors are comprehensively explained on the bases of interplay between the unit gravity and centrifugal force generated by rotation of the coil. This theory is successfully extended to explain the two-phase behavior in a coil undergoing the type-I and type-J planetary motions.
Results and discussion: The type-I planetary motion produces the centrifugal force distribution similar to that of slowly rotating coil in unit gravity (Stage I), where both phases competitively move toward the head of the coil. In contrast, the type-J planetary motion displays complex distribution patterns of centrifugal force according to the location of the coil on the holder hence the two-phase motion varies with the ß values. When ß is 0.5 - 0.75, the force pattern simulates that of the rotating coil in unit gravity at 120 rpm (Stage III) where the lighter phase moves toward the head leaving the heavier phase behind.
Conclusion: This clearly demonstrates the importance of the proper choice of ß values in high-speed countercurrent chromatography utilizing the type-J planetary motion.
{"title":"Two-phase Motion in Hydrodynamic Counter-current Chromatography.","authors":"Yoichiro Ito","doi":"10.2174/2213240606666190912161221","DOIUrl":"10.2174/2213240606666190912161221","url":null,"abstract":"<p><strong>Background: </strong>Motion of the two mutually immiscible liquids in hydrodynamic countercurrent chromatographic systems is speculated based on the observation of their behavior in a closed coiled tube rotating in unit gravity.</p><p><strong>Materials and methods: </strong>The experiment revealed an up and down pattern of four stages of two-phase volume ratio occupied at the head end of the coil according to the rotation speed. These two-phase behaviors are comprehensively explained on the bases of interplay between the unit gravity and centrifugal force generated by rotation of the coil. This theory is successfully extended to explain the two-phase behavior in a coil undergoing the type-I and type-J planetary motions.</p><p><strong>Results and discussion: </strong>The type-I planetary motion produces the centrifugal force distribution similar to that of slowly rotating coil in unit gravity (Stage I), where both phases competitively move toward the head of the coil. In contrast, the type-J planetary motion displays complex distribution patterns of centrifugal force according to the location of the coil on the holder hence the two-phase motion varies with the ß values. When ß is 0.5 - 0.75, the force pattern simulates that of the rotating coil in unit gravity at 120 rpm (Stage III) where the lighter phase moves toward the head leaving the heavier phase behind.</p><p><strong>Conclusion: </strong>This clearly demonstrates the importance of the proper choice of ß values in high-speed countercurrent chromatography utilizing the type-J planetary motion.</p>","PeriodicalId":10826,"journal":{"name":"Current chromatography","volume":"7 2","pages":"76-81"},"PeriodicalIF":0.0,"publicationDate":"2020-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ftp.ncbi.nlm.nih.gov/pub/pmc/oa_pdf/ab/e8/CCHG-7-76.PMC8388067.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"39402649","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-07-31DOI: 10.2174/2213240607999200813195405
M. S. Khan, J. Azmir, A. I. Da Silva Junior, Y. F. Wong, M. Mollah, Jalal T. Althakafy, M. Sarker
Green separation science involves extraction, pre-concentration and chromatographic analysis aiming at minimizing environmental impact by reducing energy and reagent usage and reducing or eliminating waste generation. However, the enrichment of trace analytes and/or the analysis of complex matrices most frequently require several steps before analysis, such as extraction, pre-concentration, clean up and preparative chromatography. Thus, alternative and greener separation techniques and solvents are replacing classical methods to diminish the carbon footprint and increase sustainability. Moreover, many innovations are also emerging to curtail the environmental impact of samples analysis; such as micro or nano analytical platforms, sensor-based systems and direct injection to high-resolution mass spectrometry. The current review provides an updated account of the green and sustainable separation science techniques. The current innovations on greener separations and their application in different fields of study are discussed.
{"title":"Strategy for Sustainable and Green Chromatographic Separation Science: Innovation, Technology and Application","authors":"M. S. Khan, J. Azmir, A. I. Da Silva Junior, Y. F. Wong, M. Mollah, Jalal T. Althakafy, M. Sarker","doi":"10.2174/2213240607999200813195405","DOIUrl":"https://doi.org/10.2174/2213240607999200813195405","url":null,"abstract":"\u0000\u0000Green separation science involves extraction, pre-concentration and chromatographic\u0000analysis aiming at minimizing environmental impact by reducing energy and reagent usage and reducing\u0000or eliminating waste generation. However, the enrichment of trace analytes and/or the analysis\u0000of complex matrices most frequently require several steps before analysis, such as extraction,\u0000pre-concentration, clean up and preparative chromatography. Thus, alternative and greener separation\u0000techniques and solvents are replacing classical methods to diminish the carbon footprint and increase\u0000sustainability. Moreover, many innovations are also emerging to curtail the environmental\u0000impact of samples analysis; such as micro or nano analytical platforms, sensor-based systems and\u0000direct injection to high-resolution mass spectrometry. The current review provides an updated account\u0000of the green and sustainable separation science techniques. The current innovations on greener\u0000separations and their application in different fields of study are discussed.\u0000","PeriodicalId":10826,"journal":{"name":"Current chromatography","volume":"300 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79686385","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-06-21DOI: 10.2174/2213240607999200621202159
Prachi Raikar, B. Gurupadayya, Sripuram Subramanyam, G. Srinivasu
Polysaccharide based chiral stationary phases (CSPs) were used to perform enantiomeric separation of Orphenadrine Citrate by Ultra-Fast Liquid Chromatography (UFLC) technique. Trials were conducted using the polar mode, reverse phase mode and normal phase mode. Amylose and Cellulose-based CSPs were used for the same. Eight Amylose-based CSPs and four Cellulose-based CSPs were used in the reverse phase mode. Five Amylose-based CSPs and two Cellulose-based CSPs were used in polar mode. The only Cellulose-based CSP used in the normal phase mode could effectively separate Orphenadrine Citrate enantiomers with a good resolution. Successful enantioseparation was obtained using Chiralcel OD-H containing Cellulose tris (3, 5-dimethylphenylcarbamate) as a chiral selector and n-hexane: Ethanol: Diethylamine (95: 05: 0.1, v/v/v) as the mobile phase. The developed method was validated in accordance with ICH guidelines (Q2R1). The proposed objectives were successfully accomplished as the developed method could effectively resolve Orphenadrine Citrate enantiomers.
{"title":"Analysis of Orphenadrine Citrate in Various Chiral Stationary Phases: A Comparative Study","authors":"Prachi Raikar, B. Gurupadayya, Sripuram Subramanyam, G. Srinivasu","doi":"10.2174/2213240607999200621202159","DOIUrl":"https://doi.org/10.2174/2213240607999200621202159","url":null,"abstract":"\u0000\u0000Polysaccharide based chiral stationary phases (CSPs) were used to perform\u0000enantiomeric separation of Orphenadrine Citrate by Ultra-Fast Liquid Chromatography (UFLC)\u0000technique. Trials were conducted using the polar mode, reverse phase mode and normal phase mode.\u0000Amylose and Cellulose-based CSPs were used for the same.\u0000\u0000\u0000\u0000Eight Amylose-based CSPs and four Cellulose-based CSPs were used in\u0000the reverse phase mode. Five Amylose-based CSPs and two Cellulose-based CSPs were used in polar\u0000mode. The only Cellulose-based CSP used in the normal phase mode could effectively separate\u0000Orphenadrine Citrate enantiomers with a good resolution.\u0000\u0000\u0000\u0000Successful enantioseparation was obtained using Chiralcel OD-H containing\u0000Cellulose tris (3, 5-dimethylphenylcarbamate) as a chiral selector and n-hexane: Ethanol: Diethylamine\u0000(95: 05: 0.1, v/v/v) as the mobile phase. The developed method was validated in accordance\u0000with ICH guidelines (Q2R1).\u0000\u0000\u0000\u0000The proposed objectives were successfully accomplished as the developed method\u0000could effectively resolve Orphenadrine Citrate enantiomers.\u0000","PeriodicalId":10826,"journal":{"name":"Current chromatography","volume":"21 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90779317","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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