Green Chromatographic Method Research Articles

Multi-assessed green sustainable chromatographic resolution of nicotine and caffeine; application to in-vitro release from a new quick mist mouth spray co-formula

The availability of well-established analytical methods is crucial to cope with the fast-ongoing research for the development of new drug delivery formulations. In this work, a rapid highly green chromatographic method was developed for the simultaneous determination of nicotine (NIC) and caffeine (CAF) to be applied for an in-vitro release study from a newly prepared quick mist mouth spray co-formula (QMS), as a complementary synergistic fast-onset relief of cravings during smoking cessation. The chromatographic resolution was accomplished on a cyano column using isocratically delivered (1.0 mL/ min) glycerol: orthophosphoric acid (OPA) (0.2 M) adjusted to pH 3.0 using 0.05 M triethylamine (5:95, v/v) and UV detection at 260 nm. Well resolved peaks of NIC and CAF were eluted at 2.1 and 3.9 min (Rs = 5.64), with linear responses between 0.1 and 20.0 µg/mL and 0.2–40.0 µg/mL, and detection limits of 0.03 and 0.07 µg/mL for NIC and CAF, respectively. The developed method showed good analytical performance (accuracy, precision, robustness, and selectivity) as well as superiority in practicality and ecological profile compared to reported methods applying GAPI, analytical eco-scale, AGREE, BAGI, and whiteness metric tool. The developed method was successfully applied for NIC and CAF determination in their pharmaceutical preparations, and artificial saliva with no significant differences from reported method results (F-test and t-test). Moreover, an in-vitro release study of NIC and CAF from QMS was performed employing the developed method that revealed diffusion-controlled release, compared to mixed diffusion/ polymer chain relaxation for marketed single component formulation, showing the superiority of QMS in reducing drug level fluctuations of NIC and CAF and improving their bioavailability.Graphical

Green Chromatographic Method for The Determination of Synthetic Azo Dyes in Processed Beef and Chicken Meat Products

Green Chromatographic Method for The Determination of Synthetic Azo Dyes in Processed Beef and Chicken Meat Products

Green chromatographic methods for determination of co-formulated lidocaine hydrochloride and miconazole nitrate along with an endocrine disruptor preservative and potential impurity

Recently, green analytical chemistry (GAC) is a key issue towards the idea of sustainability, the analytical community is focused on developing analytical methods that incorporate green chemistry principles to minimize adverse impacts on the environment and humans. Herein, we present 2 sustainable, selective, and validated chromatographic methods. Initially, lidocaine hydrochloride (LDC) and miconazole nitrate (MIC) with two preservatives; methyl paraben (MTP) and saccharin sodium (SAC) were chromatographed via TLC–densitometric method which employed ethyl acetate: methanol: formic acid (9:1:0.1, by volume) as the mobile phase with UV detection at 220.0 nm, good correlation was obtained in the range of 0.3–3.0 µg/band for MIC and LDC. Following that, RP-HPLC was successfully applied for separating quinary mixture of LDC, MIC, MTP, SAC along with LDC impurity; dimethyl aniline (DMA) using C18 column, and a gradient green mobile phase composed of methanol and phosphate buffer (pH 6.0) in different ratios with a flow rate 1.5 mL/min and UV detection at 210.0 nm, linearity ranges from 1.00 to 100.00 µg/mL for MIC, 2.00–100.00 µg/mL for LDC and 1.00–-20.00 µg/mL for MTP and DMA. No records to date regarding the determination of the two drugs, besides MTP and DMA. The proposed methods were validated according to the ICH guidelines and applied successfully to the analysis of the compounds. The methods' results were statistically compared to those obtained by applying the reported one, indicating no significant difference regarding both accuracy and precision. The methods' greenness profiles have been assessed and compared with those of the reported method using different assessment tools.Graphical

Unique green chromatographic method for the qualitative and quantitative analysis of ketoconazole, its impurities and preservatives from ketoconazole cream formulation: Identification of degradants by Q-ToF LCMS and Robustness by Design of Experiments

Current research portrays a simultaneous determination method for the qualitative and quantitative analysis of Ketoconazole, its impurities and preservatives from Ketoconazole cream formulation. The unique method was developed using the RP-UPLC technique with a gradient elution mode. The separation of isomeric preservative components was achieved on the Waters Acquity UPLC BEH C18 column using phosphate buffer as mobile phase A and a mixture of phosphate buffer and acetonitrile, 30:70 (v/v) as mobile phase B. The set flow rate, injection volume, column oven temperature, and detector wavelengths were 0.5 mL/min, 2.0 μL, 30 °C, and 225 nm, respectively. The method's stability indicating nature was achieved through forced degradation studies. The active drug was prone to acidic and oxidative conditions. The attained acidic and peroxide degradant peaks were identified using Q-ToF LCMS. The developed method was validated per regulatory guidelines, and the data showed superior precision with a %RSD of 0.7 for Ketoconazole, 0.8 for preservatives, and 1.6 for impurities. All the components showed excellent linearity (r > 0.999) within the 50–150% range for Ketoconazole and preservatives and from LOQ to 150% for impurities. The mean accuracy data resulted from 99.4% to 99.9% for Ketoconazole, 99.9%–106.0% for impurities, and 100.3%–101.4% for butylated hydroxyanisole. The robust method conditions were evaluated by the Design of Experiments. The greenness and eco-friendliness of the method were demonstrated by modern tools such as the analytical eco scale, GAPI and AGREE. The final UPLC method is specific and suitable for determining the preservatives, drug content and impurities of Ketoconazole simultaneously from its cream formulation, which saves analysis time and solvent consumption supporting towards the green chemistry principles.

Novel experimental design paradigm for development of eco-friendly gradient chromatographic method for simultaneous determination of metronidazole and spiramycin.

This work describes the innovative experimental design-assisted development of a green gradient chromatographic method for concomitant analysis of metronidazole (MTR) and spiramycin (SPR). Two different designs including fractional factorial and Box-Behnken designs were implemented for screening and optimization steps, respectively. The optimum chromatographic conditions involved a mobile phase consisting of ethanol and 20mM sodium dihydrogen phosphate solution (pH adjusted to 2.5) in the ratio 2:98 (v/v) for 2 min then the ratio changed to 30:70 (v/v). The flow rate was 1.3mL/minute. Separation and analysis were performed on X-bridge C18 (150mm × 4.6mm × 3.5μm) column with diode array detector set at 230nm. Column oven temperature was 40°C. A linear response was acquired over the range of 5-125μg/mL for both drugs. Detection and quantitation limits were 0.86 and 2.62μg/mL for MTR and 0.92 and 2.83μg/mL for SPR, respectively. The method was implemented for determination of both drugs in three tablet formulations. The method was proved to be green as evaluated by three assessment tools. The application of experimental designs assists in development of a robust green chromatographic method in gradient elution mode for determination of both drugs within reasonable time.

Green chromatographic methods and in vitro pharmacological analysis of Varronia curassavica leaf derivatives.

Varronia curassavica displays anti-inflammatory, antiulcerogenic, and antioxidant activities. Herein, we employed new UHPLC -UV green chromatographic methods for the analysis of in vitro antioxidant and anti-inflammatory activities of V. curassavica and its embryotoxicity in Zebrafish. Cordialin A, brickellin, and artemetin were purified from the ethanol (EtOH) extract of V. Curassavica leaves and identified using spectrometric techniques. In line with Green Analytical Chemistry principles, the proposed UHPLC methods involve the use of ethanol as organic modifier with low mobile phase consumption, and without sample pretreatment (OLE-UHPLC-UV). The application of the Agree and HPLC-EAT tools for greenness assessment yielded this pattern: HPLC-UV (reference) < UHPLC-UV < OLE-UHPLC-UV. Zebrafish assay results showed that 70% EtOH extract of V. Curassavica leaves exhibited lower toxicity compared to 100% EtOH extract, with LC50 of 164.3 and 122.9 µg/mL, respectively, in 24 h post fertilization. Some embryos exhibited malformation phenotypes in the heart, somites, and eyes, mainly in higher extract concentrations. Extracts and brickellin exhibited higher antioxidant activity in the DPPH• assay, while brickellin + artemetin displayed higher antioxidant activity compared to the extracts and isolated flavones in the O2•- and HOCl/OCl- scavenging assays. Cordialin A and brickellin exhibited low COX-1, COX-2, and phospholipase A2 inhibition.

Exploration of HPTLC Technology for Rapid Chemical Fingerprinting and Simultaneous Determination of Bioactive Constituents from Clitoria ternatea Linn.

AbstractThe analytical methods used for herbal analysis are need to be economic, fast and also produce minimum quantities of hazardous chemical waste. Presently analytical community put interest in the research area of non‐hazardous and eco‐friendly practices to develop various green chromatographic methods for routine quality analysis. High cost of phytochemical analysis and uses of hazardous chemicals with high‐end sophisticated instrument, the attempt made to develop a simple analytical method for multiple samples with short time and less uses of solvents. A HPTLC method was developed for simultaneous determination of biological important constituents like β‐sitosterol, taraxerol, clitorienolactone B and β‐sitosterol glycoside from Clitoria ternatea Linn. The proposed method was validated and satisfied the ICH guidelines to demonstrate that the method is adaptable for its intended purpose. The method is simple, sensitive and economic it therefore embraces potential for detection, monitoring, and simultaneous quantification of the four bioactive compounds for C. ternatea and could also be apply to other species.

Pre-column Derivatization¸ Elution Order, Molecular Configuration and Green Chromatographic Separation of Diastereomeric Derivatives of β-Amino Alcohols

A green chromatographic method was developed for the indirect enantio-separation of racemic amino alcohols by introducing a micellar mobile phase for the HPLC. Here, cyanuric chloride-based activated chiral reagents were prepared, characterized, and used to derivatize racemic amino alcohols into diastereomeric derivatives. The chromatographic separation of the prepared diastereomeric derivatives was achieved on the C18 column of the RP-HPLC using a surfactant-based (Brij-35 + SDS) aqueous mobile phase (as an alternative to organic solvents). The impact of the varying concentration of surfactants in the mobile phase and pH of buffer on the chromatographic separation was optimized. Additionally, the DFT calculations were performed, and the absolute configurations and elution orders of the diastereomeric derivatives were investigated. Developed method’s robustness and selectivity was optimized by performing validation studies (LOD = 0.286 ng/mL; LOQ = 0.858 ng/mL). Also, the green assessment score was calculated for the developed method (84 scores; an excellent green method).

Green Chromatographic Method for Determination of Active Pharmaceutical Ingredient, Preservative, and Antioxidant in an Injectable Formulation: Robustness by Design Expert.

We report an efficient HPLC method for simultaneous qualitative and quantitative analysis of lincosamide antibiotic injectable formulations containing Clindamycin phosphate (CMN), benzyl alcohol (BA), and ethylenediaminetetraacetic acid (EDTA) as major ingredients. The three components were separated by Phenomenex prodigy C8 (250 mm × 4.6 mm, 5 μm) HPLC column, flow rate 1.1 mL/min, injection volume 30 μL, and column temperature 35 °C, using 0.05 M sodium acetate buffer (pH 4.5) with acetonitrile (ACN) in the ratio of 80:20 (v/v). The detection wavelength was set as 240 nm. The method was validated as per International Conference on Harmonization (ICH) guidelines and was confirmed to be specific, precise, accurate, and linear. Method robustness was executed by utilizing quality in the design of the experiment. Accuracy results were found to be 99.3–100.5% for CMN, 99.3–100.8% for BA, and 99.1–100.3% for EDTA. Precision results were obtained as % relative standard deviation (RSD): 0.6% for CMN, 0.4% for BA, and 0.4% for EDTA. Correlation coefficient (r2) values were obtained as >0.999 for the three components. Analytical solutions are stable for 48 h at benchtop and refrigerator conditions. The greenness of the analytical method was evaluated by the Green Analytical Procedure Index (GAPI), National Environmental Method Index (NEMI), analytical eco-scale, and Analytical Greenness (AGREE) tools to confirm that the method is eco-friendly.

Development and Validation of Green Chromatographic Approaches for Simultaneous Determination of Aspirin, Rosuvastatin and Clopidogrel in their Tertiary Mixture

Reduction of environmental pollution sources is the main target of green chemistry; it is applied across the life cycle of a chemical product. Scientists try to switch to eco-friendly practices to diminish the negative impact of chemicals and solvents on the environment. Analytical chemistry is one of the main fields that mounted green chemistry approach. In this work, sensitive and selective green chromatographic methods with UV detection are described for the simultaneous determination of aspirin, rosuvastatin and clopidogrel. The first proposed method is an RP-HPLC one, which was described and successfully validated for the simultaneous separation and determination of the three components on Prontosil Hyperchom C18 (250 × 4.6mm, 5μm) column using an isocratic elution. The second method was a TLC spectrodensitometry in which the three components were separated, identified and quantified. The drugs were applied on silica gel plates, and developed using n-heptane: acetone: glacial acetic acid (60:40:0.4, by volume). The three drugs resolved bands were quantified by spectrodensitometric scanning at 240nm. Both methods were validated according to ICH, statistically compared to the official methods with full greenness investigation to confirm that the proposed methods are viable alternatives for quality assessment of this combination.

Green chromatography as a novel alternative for the quality control of Serjania marginata Casar. Leaves

In the quest for efficient sustainable alternative techniques for the quality control of medicinal plants, the present work sought to develop a green chromatographic method for the fingerprinting and standardization of the extract of Serjania marginata leaf – plant species used in folk medicine for the treatment of stomach ache. The analytical method was developed using the HPLC-PDA technique with only ethanol and water as solvents and based on the application of fractional factorial planning for the screening of variables and Doehlert matrix for the optimization procedure. The proposed green chromatographic method was compared with the HPLC method reported in the literature using the following metrics and taking into account the chromatographic performance and environmental impact of the methods: Green Chromatographic Fingerprinting Response (GCFR), HPLC-EAT (EAT – Environmental Assessment Tool), Analytical GREEnness (AGREE) and Green Analytical Procedure Index (GAPI). The green chromatographic technique was validated through the analysis of the following parameters: selectivity, linearity, detection and quantification limits, precision and robustness, while the standardization of the extract was performed through the quantification of protocatechuic acid, (+)-catechin, (–)-epicatechin, and apigenin derivatives. The optimum conditions for the application of the proposed chromatographic method were as follows: linear gradient from 10 to 55% of ethanol in 35 min, temperature of 60 °C, flow rate of 1.11 mL min−1, and phenyl hexyl column. Under these conditions, a desirability value of 0.93866 was obtained with maximum responses of 25.327 and 12.189, for peak number and GCFR, respectively. In addition, the analysis of the plant extract by HPLC-MS/MS, under the same optimized method, allowed the annotation of 21 phenolic compounds, including a phenolic acid, proanthocyanidins and flavonoids derived from quercetin, apigenin and luteolin. The results obtained show that the proposed method has good accuracy and robustness, apart from being environmentally friendly – once it satisfies the principles of Green Chemistry.

Two green chromatographic methods for the quantification of tamsulosin and solifenacin along with four of their impurities.

Modern analytical procedures often include impurity profiling to verify the potency, safety, and effectiveness of new formulations. We had to develop techniques based on green analysis since the detrimental influence of solvents and chemicals on the environment has now become a serious concern. Two selective, sensitive, and green liquid chromatography methods were established and fully validated for quantitation of tamsulosin hydrochloride and solifenacin succinate along with four of their official and/or related impurities namely; tamsulosin sulfonic acid, tamsulosin impurity H, solifenacin impurity A and solifenacin impurity C. The first used high-performance thin-layer chromatography with silica gel 60 F254 plates as the stationary phase and an elution system of ethyl acetate:butanol:glacial acetic acid (10.0:0.4:0.1, by volume) and a scanning wavelength of 225.0nm. The second method depended on HPLC with diode array detection. Chromatographic separation was accomplished on a Zorbax SB C18 (250 × 4.6 mm2 , 5 μm) column utilizing a mixture of 10.0mM sodium dihydrogen phosphate (pH 3.0, adjusted by o-phosphoric acid) and methanol, at a flow rate of 0.8mL/min in a gradient elution mode and then the separated peaks were scanned at a wavelength of 225.0nm. To assess the greenness profile, three distinct methodologies were applied.

Direct injection green chromatographic method for simultaneous quantification of amoxicillin and amikacin in maternity hospital wastewater (Sagar, India)

Amoxicillin (AMO) and amikacin (AMK) are broad-spectrum antibiotics that are most preferably given post-delivery (normal and cesarian) in the maternity hospitals located in Sagar city (Madhya Pradesh), India. Both the antibiotics make their way through sewage/drainage systems into the environment in the form of metabolized and unmetabolized compounds. Growing concern about the contamination of wastewater by antibiotics requires fast, sensitive and eco-friendly techniques. Therefore a simple, rapid and environmental friendly chromatographic method has been developed for simultaneous determination of AMO and AMK in maternity hospital wastewater samples. A micellar liquid chromatographic (MLC) method was developed with a C18 column (250 mm × 4.6 mm), sodium dodecyl sulphate (SDS; 0.15 M), 1-butanol (7%) as a modifier, pH 5 and photo diode detector (PDA) at 270 nm and 256 nm for AMO and AMK respectively. The method was fast with analysis time below 9 min. In the present MLC method, linearities (r > 0.998), limits of quantification in the range of 0.02–0.04 μg/mL, repeatabilities, and intermediate precision below 4.9% were adequate for the quantification of AMO and AMK. The proposed method can be utilized to detect and quantify both the antibiotics in various samples by hospitals, pharmaceutical companies, pollution control board, municipal corporations, etc.

Green chromatographic methods for simultaneous micro-determination of empagliflozin, linagliptin with metformin and its pharmacopoeial impurities in pure form and triple combination tablets: A comparative study

Green analytical chemistry (GAC) is gaining great interest with the respect of global environmental pollution control (EPC). Consequently, we have developed two green chromatographic methods for the simultaneous precise and selective estimation of empagliflozin (EMP), linagliptin (LNA) with Metformin (MET) and its pharmacopoeial impurities cyanoguanidine (CGN) and melamine (MLN). The scientific database lacks any analytical reports tackling such concurrent estimation of the five cited analytes. The first developed method is a reversed phase HPLC-DAD employing Agilent C18 column (4.6 × 250 mm, 5 μm p.s.) and a mobile phase composed of methanol and 0.01 M sodium dihydrogen orthophosphate buffer of pH 2.55 (adjusted with orthophosphoric acid) eluted in a gradient mode with detection at 218 and 224 nm.The second method is HPTLC using Merk TLC plates precoated with 60 F 254 silica gel on aluminium sheet as the stationary phase developed with ethanol: ethylacetate: water (3.5: 3:1, v/v/v, respectively) as mobile phase and scanned at 216 and 224 nm. The proposed methods offered neat separation and quantitation of the five analytes in their pure form and in the triple combination tablets. Both methods were validated as per the ICH guidelines in terms of linearity, range, accuracy, precision, specificity and robustness. Moreover, Greenness assessment of the developed methods was carried out using the Analytical Eco-Scale. Further evaluation of the methods’ ecofriendliness and comparison with previously reported methods was performed using NEMI, GAPI and the novel AGREE tool.

Eco-friendly and green chromatographic method for the simultaneous determination of chlorocresol and betamethasone dipropionate in topical formulations using Box–Behnken design

Eco-friendly and green chromatographic method for the simultaneous determination of chlorocresol and betamethasone dipropionate in topical formulations using Box–Behnken design

Cost-effective green chromatographic method for the simultaneous determination of four commonly used direct-acting antiviral drugs in plasma and various pharmaceutical formulations

This article presents the simultaneous determination of multiple recently approved direct-acting antiviral (DAA) regimens using a sensitive, robust method. Reversed-phase high-performance liquid chromatographic method (RP-HPLC) has been developed to represent a green alternative of other reported methods for the simultaneous determination of the most common four DAAs used for chronic hepatitis C treatment, including sofosbuvir (SF), ledipasvir (LD), daclatasvir (DC), velpatasvir (VP) and tenofovir (TO) as internal standard (IS) in bulk, pharmaceutical dosage form and plasma samples. This method was performed with an environment-friendly mobile phase with the least amount of energy consumption and waste generation. Chromatographic conditions have been optimized in order to obtain well-resolved symmetrical peaks within a reasonable elution time. Separation was achieved using Waters XBridge BEH C18 Column (4.6 × 150 mm) using isocratic elution mode at a flow rate 0.8 mL.min−1 with the mobile phase 0.1% (v/v) triethylamine acidified water with ortho-phosphoric acid (OPA) pH 2.53 and acetonitrile in the ratio (70:30 v/v). Sample extraction was done using diethyl ether for the analyte and IS extraction from the plasma samples. The suggested method was validated within the concentration range (0.4–20 μg.mL−1) for all the studied drugs according to the ICH guidelines. Calibration plots showed a linear relationship for SF, LD, DC and VP with correlation coefficients ≥ 0.9995 and acceptable recoveries. The method has been applied for the analysis of the studied drugs in plasma samples and pharmaceutical dosage forms without any matrix interference and with % RSD less than 2%, indicating the method to be precise. The suggested method was also assessed using the analytical Eco-scale tool and Green Analytical Procedure Index (GAPI) by comparing the method with other reported methods in terms of sample preparation, consuming hazardous reagents, instrument energy consumption and waste generation. Eco-scale and GAPI results proved the greenness of our proposed method. Moreover, the proposed method has the advantage of analyzing several pharmacologically related drugs in the same run simultaneously, which allows the analysis of alternative therapeutic formulations under the same running conditions. Thus, much effort and time is saved for developing a specific method for every pharmaceutical mixture. This promotes the proposed method to be used for both quality control analysis and any bioavailability study for the simultaneous determination of any of the four antiviral drugs in the pharmaceutical formulation or plasma samples without any harmful effect on the environment or human health.

Validated green chromatographic methods for determination of amlodipine and celecoxib in presence of methylacetophenone.

Aim: Green, accurate and rapid methods, namely LC-MS/MSand thin layer chromatography-densitometric methods, were developed for determination of amlodipine besylate and celecoxibin presence of its process-related impurities, 4-methylacetophenonein pure and formulated tablets. Results: LC-MS/MS was achieved on ZORBAX Eclipse Plus C18 column using methanol:aqueous solution of 5mM formic acid (95:5v/v). High sensitivity with low limit of detectionvalues 0.00028, 0.00027 and 0.0003 for amlodipine, celecoxib and 4-methylacetophenone, respectively were obtained. While, thin layer chromatography-densitometric was established using methanol:water:ammonia (70:25:1.5, by volume). Good linearity was obtained in the range of 0.1-10μg/band, 1-150μg/band and 0.01-2μg/band for amlodipine, celecoxib and 4-methylacetophenone, respectively. Conclusion: The proposed method validation was achieved according to ICH guidelines. Those methods possess advantages of being ecofriendly methods which permit their application in quality control laboratories.

Screening of some banned aromatic amines in textile products from Indian bandhani and gamthi fabric and in human sweat using micellar liquid chromatography

Certain dyes in textile products, which are capable of reductively splitting into carcinogenic aromatic amines, are strictly controlled in many countries. A simple, rapid, sensitive and green chromatographic method has been developed and validated for the simultaneous determination of 4-aminophenol (4-AMP), p-phenylenediamine (p-PPD) and benzidine (BNZ), banned aromatic amines in dyeing clothes and human sweat. The separation was achieved using a micellar mobile phase of 0.1 M SDS, 4% 1- butanol (v/v) buffered to pH 7 with sodium dihydrogen phosphate, flowing under isocratic mode at 1 mL/min through a C18 column. Photodiode array detector was set at 210 nm. Using the above chromatographic conditions, 4-AMP, p-PPD and BNZ were eluted at 3.5 min, 4.7 min. and 5.4 min., respectively, adequately resolved. The method was validated by Standard Practices for Method Validation in Forensic Toxicology guideline for the industry in terms of selectivity, calibration curve, linearity (r2 = 0.999), trueness (relative bias, −3.5 to 7%) precision (relative standard deviation, <8.5%), and robustness of selected compounds. This method was sensitive enough for the routine analysis of aromatic amine in textile material with limit of detection in the (0.01 to 0.04 μg/mL range and limit of quantification (0.03–0.13 μg/mL). The method was successfully applied to dyed clothes and sweat samples. The main advantage of the developed method is the easy extraction step of the analytes from incurred samples without any further cleanup, which reduces per sample analysis cost and the total time of analysis. The developed method could easily replace regular chromatographic technique used for their detection.

Determination of the abused intravenously self-administered madness drops (Tropicamide) by liquid chromatography in rat plasma; an application to pharmacokinetic study and greenness profile assessment

Tropicamide (TPC) is an antimuscarinic ophthalmic solution. Recently, it is reported to be used intravenously for recreational purposes. Misuse of the drug may leads to several effects such as slurred speech, unconsciousness, hallucinations, dysphoria, suicidal feelings, convulsions, and tachycardia. Two rapid and sensitive green chromatographic methods were newly established for detection and quantification of TPC abuse in rat plasma. The proposed TLC-densitometric method relied on the separation of TPC and the internal standard paracetamol (PCM) using a developed system of ethyl acetate: ethanol (9:1, v/v) on TLC silica gel 60 F254 plates and detection was performed at 210.0 nm. Linearity was achieved over a concentration range of 0.20–5.00 µg/band for TPC using 0.50 µg/band of PCM. On the other hand, the developed RP-HPLC method was based on the separation of TPC and sofosbuvir (SOF) as an internal standard using a mobile phase consisting of ethanol and water in the ratio of (45: 55, v/v) on ZORBAX Eclipse Plus® C18 column (250 × 4.6 mm, 5 µm) at a flow rate of 1.8 mL/ min and UV detection at 210.0 nm. Linearity was obtained over the concentration range of 0.10–30.00 µg/mL for TPC using 10.00 µg/mL of sofosbuvir (SOF) as an internal standard. Different evaluation tools assessed and measured the greenness profile of the established methods. On the validation of developed methods FDA recommendation was followed and all the results obtained agreed with acceptance criteria. The suggested methods were successfully used to study the pharmacokinetic parameters of TPC in rat plasma. This is the first article related to TPC abuse for determining the traces of the studied drug in rat plasma. The developed methods can be used for further monitoring of TPC abuse in addicted people plasma.

A sensitive micellar liquid chromatographic method for the rectification of enantiomers of esmolol, and determination of absolute configuration and elution order

A green chromatographic method is proposed for the enantioseparation of Esmolol (Amino alcohol) in which aqueous solution of the mixed surfactants is used as the alternative of organic solvents. In this work, the diastereomeric derivatives of racemic esmolol were prepared, under microwave heating conditions, using highly reactive activated chiral esters of the (S)-levofloxacin, (S)-ketoprofen, and (S)-ibuprofen. The prepared diastereomeric derivatives were separated using surfactant based mobile phase on RP-HPLC. The effect of the varying concentration of surfactant (Brij-35 and SDS) in the eluting phase was investigated for separation and elution of synthesized diastereomeric derivatives. The green assessment score was calculated (obtain score points were 82) for developed method. In addition, the density functional theory calculations were performed, using Gaussian 09 rev. A.02 and hybrid density functional B3LYP with 6-31 G* basis set program, in order to develop lowest energy optimized structures of diastereomeric derivatives. The optimized structures used to predict elution order of synthesized diastereomeric derivatives. Our method was characterized by the following validation parameter: LOD (0.289 ng mL−1), LOQ (0.867 ng mL−1), calibration range (0.006–6.0 mg mL−1), correlation coefficient (0.999) and recovery (99.97 and 99.85% for intra-day assay and 99.42 and 99.75% for inter-day assay).