Liquid Chromatography Technique Research Articles

Profiling Bioactive Compounds in the Bark of Cinchona officinalis L. and Anti-arthritic Properties Thereof

The bark samples of C. officinalis were collected from The Nilgiris district of Tamil Nadu. The collected samples were processed and extracted using methanol solvent. The extracts showed high yield of secondary metabolites especially alkaloids, phenols, flavonoids, steroids, terpenoids, sterols, quinones and tannins. Alkaloid content was very high in C.officinalis followed by phenol, flavonoid, steroid and Tannin. The secondary metabolites present in C. officinalis (Bark) were isolated, purified, identified and characterized using differential Chromatographic techniques such as TLC, HPLC and GC-MS/ MS. The compounds identified using High Performance Liquid Chromatography (HPLC) technique in bark of C. officinalis in the retention times of 1.750, 2.250, 4.016 and 7.266 minutes were quinine, isoquinidine and cinchonidine. The compounds were then characterized using GC- MS/ MS technique with reference to NIST library. The compounds were eluted from the bark of C. officinalis in the retention time of 9.569, 10.488, 11.814, 13.593, 14.282, 16.542, 16.967, 23.494, 24.954, 25.151, 25.988, 26.752, 26.982, 27.906, 28.277, 31.454, 33.604, and 35.744 minutes. By correlating the retention times with (NIST) mass spectral library the eluted compounds were confirmed as Phthalic acid, Hexadecanoic acid,1,2,3,5-Cyclohexanetetrol, Cinchonab-9-one, 9,12-Octadecadienoic acid (Z,Z)-, Heptadecanoic acid, Quinine, Cinchonine, Cinchonidine, Phenol, Quinine, and gamma.-Sitosterol. The phytochemicals present in the C. officinalis (Bark) samples were evaluated for their biological properties viz., anti-inflammatory activity and anti-arthritic activity in in-vitro conditions. Anti- inflammatory properties of plant samples were tested by protein denaturation method using diclofenac (75 mg/ ml concentration) as positive control. The methanol extract of C.officinalis (Bark) showed anti- inflammatory properties of range between 17.0 and 57.3%. Anti- arthritic activity of bark extract of C. officinalis (75 mg/ ml concentration) was evaluated by albumin denaturation method using diclofenac (75 mg/ ml concentration) as positive control. The methanol extract of C.officinalis (Bark) showed anti- arthritic properties of range between 18.4 and 58.5%. From the study it is understood that the alkaloids and polyphenols present in the methanolic extract of bark of C. officinalis were responsible for their biological properties. Hence, C. officinalis can serve as an alternative to synthetic drugs available in the market to treat arthritis subject to safety (toxicity) studies in humans. Based on the In vitro results, it was confirmed that the bark of C.officinalis possesses comparatively high biological values. Thus an herbal aerosol for arthritis may be formulated using the bark extract of C.officinalis as key ingredient and the therapeutic product will be of cost effective, easy to use and pocket friendly.

Release Kinetics of Sulfentrazone from Chitosan Clay Sulfentrazone Nanocomposite

Introduction: With a rational objective to reduce groundwater contamination from pesticides and thereby reducing ecotoxicological effect of pesticide, present research programme was carried out. Sulfentrazone is a well-known effective pesticide that is used for soybean crops. But at the same time, sulfentrazone is known for its high leaching potential through soil and could lead to ground water contamination Method: So we have synthesized a novel chitosan clay nanocomposites of sulfentrazone at three different concertations of sulfentrazone, 37.64%, 52.44% and 59.85% and its release pattern was studied at three different buffer systems like pH 2, pH 4 and pH 6. Release pattern of Sulfentrazone has been quantified by using High Performance Liquid Chromatography (HPLC) technique. Various mathematical tools have been applied to understand the release kinetics of chitosan clay sulfentrazone nanocomposites Result: Correlation coefficient (R2) of many models has been plotted and the Huguchi model was found to be the most suitable for these nanocomposites. The salient finding of this study is that the release rates of sulfentrazone at pH 4 is 68.39%, 42.62% and 37.75% after 8 hours at three different loading. This release pattern is higher than the release pattern at pH 6 and pH 2. Conclusion: Based on these release data, it is very clear that chitosan clay sulfentrazone nanocomposite can control the release of sulfentrazone at regular soil pH conditions, which is pH 6.

Development and validation of an HPLC-DAD method for the quantification of cannabigerol, cannabidiol, cannabinol and cannabichromene in human plasma and mouse matrices.

Cannabigerol, cannabidiol, cannabinol and cannabichromene are non-psychoactive phytocannabinoids, highly present in Cannabis sativa, for which numerous therapeutical applications have been described. However, additional pre-clinical and clinical data, including toxicopharmacokinetic and pharmacodynamic studies, remain required to support their use in clinical practice and new therapeutic applications. To support these studies, a new high performance liquid chromatography technique (HPLC) with diode-array detection (DAD) was developed and validated to quantify these cannabinoids in human plasma and mouse matrices. Sample extraction was accomplished by protein precipitation and double liquid-liquid extraction. Simvastatin and perampanel were used as internal standards in human and mouse matrices, respectively. Chromatographic separation was achieved in 16 min on an InfinityLab Poroshell® 120 C18 column (4.6 mm × 100 mm, 2.7 μm) at 40 °C. A mobile phase composed of water/acetonitrile was pumped with a gradient elution program at 1.0 mL min-1. The technique revealed linearity in the defined concentration ranges with a determination coefficient of over 0.99. Intra and inter-day accuracy and precision values ranged from -14.83 to 13.97% and 1.08 to 13.74%, respectively. Sample stability was assessed to ensure that handling and storage conditions did not compromise analyte concentrations in different matrices. Carry-over was absent and recoveries were over 77.31%. This technique was successfully applied for the therapeutic monitoring of cannabidiol and preliminary pre-clinical studies with cannabigerol and cannabidiol. All samples were within calibration ranges, with the exception of cannabigerol after intraperitoneal administration. This is the first HPLC-DAD technique that simultaneously quantifies cannabinoids in these biological matrices, supporting future pre-clinical and clinical investigations.

Development and validation of an HPLC-DAD method for the quantification of cannabigerol, cannabidiol, cannabinol and cannabichromene in human plasma and mouse matrices.

Cannabigerol, cannabidiol, cannabinol and cannabichromene are non-psychoactive phytocannabinoids, highly present in Cannabis sativa, for which numerous therapeutical applications have been described. However, additional pre-clinical and clinical data, including toxicopharmacokinetic and pharmacodynamic studies, remain required to support their use in clinical practice and new therapeutic applications. To support these studies, a new high performance liquid chromatography technique (HPLC) with diode-array detection (DAD) was developed and validated to quantify these cannabinoids in human plasma and mouse matrices. Sample extraction was accomplished by protein precipitation and double liquid-liquid extraction. Simvastatin and perampanel were used as internal standards in human and mouse matrices, respectively. Chromatographic separation was achieved in 16 min on an InfinityLab Poroshell® 120 C18 column (4.6 mm × 100 mm, 2.7 μm) at 40 °C. A mobile phase composed of water/acetonitrile was pumped with a gradient elution program at 1.0 mL min-1. The technique revealed linearity in the defined concentration ranges with a determination coefficient of over 0.99. Intra and inter-day accuracy and precision values ranged from -14.83 to 13.97% and 1.08 to 13.74%, respectively. Sample stability was assessed to ensure that handling and storage conditions did not compromise analyte concentrations in different matrices. Carry-over was absent and recoveries were over 77.31%. This technique was successfully applied for the therapeutic monitoring of cannabidiol and preliminary pre-clinical studies with cannabigerol and cannabidiol. All samples were within calibration ranges, with the exception of cannabigerol after intraperitoneal administration. This is the first HPLC-DAD technique that simultaneously quantifies cannabinoids in these biological matrices, supporting future pre-clinical and clinical investigations.

Development and validation of stability-indicating method of etrasimod by HPLC/DAD/MS/MS technique with greenness profiling

Etrasimod, a novel selective sphingosine-1-phosphate receptor modulator, was recently approved by the U.S. Food and Drug Administration and the European Medicinal Agency for the treatment of moderately to severely active ulcerative colitis in adults. In this research, the forced degradation study as an integral part of drug product and packaging development, which generates data on degradation mechanisms, is published. The development and validation of the stability-indicating method using a superior high-performance liquid chromatography technique coupled with a diode array detector and tandem mass spectrometer was performed to support the forced degradation study and monitor the formation of degradation products. Etrasimod demonstrated good stability under elevated temperature and basic stress conditions, while acidic hydrolysis, oxidative, and photolytic degradation produced eight degradation products. The knowledge of degradation products will be useful in the long-term stability study for establishing the acceptance criteria of etrasimod as a drug substance and dosage form during quality control and stability assessment. The eco-friendliness of the developed forced degradation procedure was evaluated using various greenness appraisal tools. The green metric tools showed that the forced degradation procedure obeys eco-friendly conditions.

A porous composite sorbent incorporating a metal organic framework and zinc oxide in cryogel to extract carbamate pesticides

A composite sorbent was designed and fabricated by incorporating the Materials of Institute Lavoisier (MIL-101) and zinc oxide (ZnO) into polyvinyl alcohol (PVA) cryogel. The composite sorbent was produced to extract carbamates (carbofuran, carbaryl, isoprocarb and diethofencarb) by in-syringe solid phase extraction (SPE). MIL-101 and ZnO enhanced the adsorption of the carbamates by creating π-π stacking and hydrogen bonding, while porous PVA cryogel acted as a solid support which helped to reduce backpressure in the system. The extraction of the target carbamates was optimized by varying the amount of MIL-101 and ZnO used in the sorbent fabrication, desorption conditions, sample pH, ionic strength, sample flow rate and sample volume. The extracted target carbamates were quantitatively determined using high performance liquid chromatography technique. The developed method exhibited linearity from 1.0 to 150.0 μgL−1 for all four target carbamate pesticides with a limit of detection 0.3 µg/L. The method identified carbamates in fruit juice and white wine, obtaining recoveries from 78.1 to 108.2 % and the relative standard deviation (RSD) lower than 6.3 %. The developed composite sorbent showed good accuracy, is simple to fabricate, works rapidly and can be used for 17 extraction-regeneration cycles.

Validated Chromatography Method for Analysis of Formaldehyde Migration Levels in Bottled Drinking Water

Polyethylene terephthalate (PET) is utilized in the containment of potable water, nonetheless, it is susceptible to impairment due to temperature and duration of storage. Migration of formaldehyde from PET arises as a consequence of thermal deterioration. This study aims to ascertain the extent of formaldehyde transference in PET-contained drinking water of varying condition, subjected to diverse temperature setting and storage durations. An examination into the levels of formaldehyde migration in polyethylene terephthalate (PET) bottled drinking water was effectively carried out employing a validated high-performance liquid chromatography (HPLC) technique. A total of 162 water samples from three different PET bottled water brands sourced from supermarkets in Palu City, Central Sulawesi, Indonesia, underwent analysis. The formaldehyde assessment was executed utilizing a mobile phase composition of methanol:acetonitrile:water (48:12:40 v/v) for 12.97 minutes at a flow rate of 0.8 mL/minute on the 1st day, the 14th day, and the 42nd day while stored at room temperature and exposed to sunlight. Formaldehyde, lacking effective chromophoric entities and not readily ionizable, necessitated derivatization with 2,4-dinitrophenylhydrazine before HPLC analysis. The findings of the study demonstrated exceptional method linearity within the concentration span of 0.5 to 1321 µg/mL, exhibiting a commendable correlation coefficient of 0.999. The limit of detection (LOD) and quantification (LOQ) were determined to be 17.33 and 57.76 µg/mL, correspondingly. Precision evaluations displayed average intraday and interday values of 128.46±3.48% and 103.19±0.12%, respectively (%RSD < 2/3 CV Horwitz ratio). The intraday and interday %recovery values were computed at 97.22±3.48% and 96.83±0.14% (n = 6). The scrutiny of formaldehyde concentrations in the water samples unveiled the absence of formaldehyde migration.

Hyphenation of supercritical fluid chromatography and trapped ion mobility-mass spectrometry for quantitative lipidomics

BackgroundLipidomics studies require rapid separations with accurate and reliable quantification results to further elucidate the role of lipids in biological processes and their biological functions. Supercritical fluid chromatography (SFC), in particular, can provide this rapid and high-resolution separation. The combination with trapped ion mobility spectrometry (TIMS) has not yet been applied, although the post-ionization separation method in combination with liquid chromatography or imaging techniques has already proven itself in resolving isomeric and isobaric lipids and preventing false identifications. However, a multidimensional separation method should not only allow confident identification but also provide quantitative results to substantiate studies with absolute concentrations. ResultsA SFC method was developed and the hyphenation of SFC and TIMS was further explored towards the separation of different isobaric overlaps. Furthermore, lipid identification was performed using mass spectrometry (MS) and parallel accumulation serial fragmentation (PASEF) MS/MS experiments in addition to retention time and collision cross section (CCS). Quantification was further investigated with short TIMS ramps and performed based on the ion mobility signal of lipids, since TIMS increases the sensitivity by noise filtering. The final method was, as an exemplary study, applied to investigate the function of different ceramide synthases (CerS) in the nematode and model organism Caenorhabditis elegans (C. elegans). Loss of three known CerS hyl-1, hyl-2 and lagr-1 demonstrated different influences on and alterations in the sphingolipidome. SignificanceThis method describes for the first time the combination of SFC and TIMS-MS/MS, which enables a fast and sensitive quantification of lipids. The results of the application to C. elegans samples prove the functionality of the method and support research on the metabolism of sphingolipids in nematodes.

RP-HPLC Method for Estimation of Caspofungin in Bulk and in Parenteral Dosage Form

In order to more precisely and accurately estimate the antifungal medicine caspofungin and its parenteral dosage form, a new, straightforward, and cost-effective reverse-phase high-performance liquid chromatography (RP-HPLC) technique has been created. The accuracy, precision, linearity, specificity, and reproducibility of the method for the measurement of caspofungin in used equipment were determined during the present study’s validation according to the International Council of Harmonization (ICH) criteria. Elution was accomplished using a CHEMSIL ODS-C18 (5μm) column in isocratic mode with a mobile phase consisting of acetonitrile:ammonium acetate buffer at pH 4.8 (60:40%v/v). The mobile phase was pumped into the column at a flow rate of 1.0 mL/min, and the eluent was detected using a variable wavelength UV detector set at 210 nm. The column dimensions are 250 × 4.6 mm. The chromatogram for the optimized RP-HPLC method of caspofungin estimation had 28,99 theoretical plates (N) and a strong peak at a resolution time of 16,105 minutes. The thorough validation process led to the conclusion that the approach is stable and could be applied for the duration of the drug’s shelf life.

Research progress on the detection of water-soluble vitamins in food using liquid chromatography

Currently, liquid chromatography is widely used for the analysis and determination of water-soluble vitamins (WSVs) in functional foods. However, due to the diversity of sample characteristics and the requirement for purification accuracy, the chromatographic conditions and specific methods used vary. This paper reviews the chromatographic conditions of liquid chromatography techniques for detecting WSVs in food, as well as the selection of liquid chromatography methods in different application fields. The chromatographic conditions include chromatographic columns, column temperature, mobile phase, flow rate, and elution gradient, and the application scope of different chromatographic conditions is compared. Liquid chromatography methods include high-performance liquid chromatography and liquid chromatography-tandem mass spectrometry, and discussions are made on the applications and prospects of these two methods under different chromatographic conditions. Therefore, this review provides research insights into different chromatographic conditions and methods for food quality inspection and biochemical analysis research.

Investigation of Retention Mechanism of B2 and B3 in Home-Made ZIC-HILIC Columns and Its Application for The Simultaneous Estimation in Multivitamin Tablets

In the present study, the retention behavior of two vitamins (B2 and B3) was investigated using a zwitterionic hydrophilic interaction liquid chromatography technique (ZIC-HILIC) on two home-made columns, and two analytical methods for these vitamins were established as a result. Several chromatographic parameters were carefully investigated and optimized. The best separation was achieved on two new home-made columns (ZIC-1 and ZIC-3) employing acetonitrile/sodium acetate buffer as the mobile phase (40 mM, pH 4.75). The target vitamins were detected at 254 nm. In the ZIC-1 and ZIC-3 columns, the linear ranges of the target vitamins (B2 and B3) were 0.06-11.0 and 0.08-7.0 µg/mL, respectively. For both target vitamins, the detection and quantitation limits of the suggested methods were 0.011-0.055 and 0.033-0.166 µg/mL, respectively. They also showed high precision (RSD ≤ 0.93), linearity (r2 ≥ 0.9988), and recovery (between 99.0 and 101.71%). The suggested procedures have been validated and tested on multivitamin tablets, proving that they are suitable for analyzing food supplements for these tablets, and acceptable results were obtained for the study.

Modern Chromatographic Methods for Determination Flavonoids

Flavonoids are a prominent group of plant phenolics (polyphenol group)extensively present in the human diet and associated with health promotion. Flavonoids are essential in various pharmaceutical, nutraceutical, and cosmetic applications. To collect and categorize these compounds, we comprehensively assessedHigh-performance liquid chromatography (HPLC) techniques published to analyze flavonoids in various matrices. Mostdocumented methods employed liquid chromatography with ultraviolet detection (HPLC-UV) and tandem mass spectrometry (LC-MS/MS) methods. Among chromatographic techniques, reversed-phaseliquidchromatographyremains the predominant and efficient method for separating various analytes. This review explores the primary chromatographic methods used to separate and quantify flavonoids in herbs, fruits, and biological samples. This article exam inesrecent literature on applying liquid chromatography with different detection methods for analyzing flavonoids. To examine recent literature on applying liquid chromatography with different detection methods for analyzing flavonoids. It offers valuable insights to researchers as they prepare to develop quantification methods.

Duckweed (Lemna minor D0158): a promising protein source for food security

Duckweeds, recognized as the fastest growing aquatic flowering plants, exhibit substantial biomass production. Recently, they have been emerged as a potential industrial crop for efficient and eco-friendly protein production and nutrient recovery compared to conventional crops. The objective of the study was to determine the biomass accumulation rate, protein content and amino acid analysis of duckweeds (Lemna minor D0158).We cultured L. minor D0158 from its preserved state in the gene bank into both aseptic (in-vitro) and open condition at controlled room. The medium was Hoagland Solution (HS) mixed with sucrose in in-vitro condition while 1/5 concentration of HS (without sucrose) was in the open condition. Subsequently, we determined the dry biomass growth by calculating the weight difference adopting the Bergmann Method, and then calculated the protein percentage following the Kjeldahl Method. Moreover, the amino acid profiling was obtained using the Hydrolysis and Liquid Chromatography Technique. Later on, we compared the results with those of the other duckweeds and soybean together with the FAO requirements. We found that L. minor D0158 possessed the dry biomass growth rate of 6.72 g/m2/d with 33.13% protein content within 7-day cultivation period. Moreover, it exhibited significantly higher levels of branched chain amino acids (BCCAs) than soybean and met the FAO requirements. However, methionine (Met) content was found to be slightly low. The study suggested that L. minor D0158 might offer a sustainable solution for protein food security in future.

Biosensor Strip for Rapid On‐site Assessment of Levodopa Pharmacokinetics along with Motor Performance in Parkinson's Disease

AbstractWhile levodopa (L‐Dopa) is the primary treatment for alleviating Parkinson's disease (PD), its efficacy is hindered by challenges such as a short half‐life and inconsistent plasma levels. As PD progresses, the rising need for increased and more frequent L‐Dopa doses coupled with symptom fluctuations and dyskinesias underscores the urgency for improved comprehension of the interplay between L‐Dopa levels and PD motor symptoms. Addressing this critical need, we present a decentralized testing method using a disposable biosensor strip and a universal slope (U‐slope) calibration‐free approach. This enables reliable, rapid, simple, and cost‐effective decentralized L‐Dopa measurements from capillary blood. A pilot study with PD persons demonstrates the ability to monitor real‐time L‐Dopa pharmacokinetics from fingerstick blood after oral L‐Dopa‐Carbidopa (C–Dopa) tablet administration. Correlating capillary blood L‐Dopa levels with PD motor scores revealed a well‐defined inverse correlation with temporal motor fluctuations. We compared the resulting dynamic capillary blood L‐Dopa levels with plasma L‐Dopa levels using the traditional but clinically impractical high‐performance liquid chromatography technique. By providing timely feedback on a proper L‐Dopa dosing regimen in a decentralized and rapid fashion, this new biosensing platform will facilitate tailored optimal L‐Dopa dosing, towards improving symptom management and enhancing health‐related quality of life.

Chemometric-based drug discovery approaches from natural origins using hyphenated chromatographic techniques.

Isolation and characterization of bioactive components from complex matrices of marine or terrestrial biological origins are the most challenging issues for natural product chemists. Biochemometric is a new potential scope in natural product analytical science, and it is a methodology to find the compound's correlation to their bioactivity with the help of hyphenated chromatographic techniques and chemometric tools. The present review aims to evaluate the application of chemometric tools coupled to chromatographic techniques for drug discovery from natural resources. The searching keywords "biochemometric," "chemometric," "chromatography," "natural products bioassay," and "bioassay" were selected to search the published articles between 2010-2023 using different search engines including "Pubmed", "Web of Science," "ScienceDirect," and "Google scholar." An initial stage in natural product analysis is applying the chromatographic hyphenated techniques in conjunction with biochemometric approaches. Among the applied chromatographic techniques, liquid chromatography (LC) techniques, have taken up more than half (53%) and also, mass spectroscopy (MS)-based chromatographic techniques such as LC-MS are the most widely used techniques applied in combination with chemometric methods for natural products bioassay. Considering the complexity of dataset achieved from chromatographic hyphenated techniques, chemometric tools have been increasingly employed for phytochemical studies in the context of determining botanicals geographical origin, quality control, and detection of bioactive compounds. Biochemometric application is expected to be further improved with advancing in data acquisition methods, new efficient preprocessing, model validation and variable selection methods which would guarantee that the applied model to have good prediction ability in compound relation to its bioactivity.

Biosensor Strip for Rapid On-site Assessment of Levodopa Pharmacokinetics along with Motor Performance in Parkinson's Disease.

While levodopa (L-Dopa) is the primary treatment for alleviating Parkinson's disease (PD), its efficacy is hindered by challenges such as a short half-life and inconsistent plasma levels. As PD progresses, the rising need for increased and more frequent L-Dopa doses coupled with symptom fluctuations and dyskinesias underscores the urgency for improved comprehension of the interplay between L-Dopa levels and PD motor symptoms. Addressing this critical need, we present a decentralized testing method using a disposable biosensor strip and a universal slope (U-slope) calibration-free approach. This enables reliable, rapid, simple, and cost-effective decentralized L-Dopa measurements from capillary blood. A pilot study with PD persons demonstrates the ability to monitor real-time L-Dopa pharmacokinetics from fingerstick blood after oral L-Dopa-Carbidopa (C-Dopa) tablet administration. Correlating capillary blood L-Dopa levels with PD motor scores revealed a well-defined inverse correlation with temporal motor fluctuations. We compared the resulting dynamic capillary blood L-Dopa levels with plasma L-Dopa levels using the traditional but clinically impractical high-performance liquid chromatography technique. By providing timely feedback on a proper L-Dopa dosing regimen in a decentralized and rapid fashion, this new biosensing platform will facilitate tailored optimal L-Dopa dosing, towards improving symptom management and enhancing health-related quality of life.

Histidine-modified pillar[5]arene-functionalized mesoporous silica materials for highly selective enantioseparation

Chiral enantiomers, especially the enantiomers of chiral drugs often exhibit different pharmacological activity, metabolism and toxicity, thus it is of great research significance to scientifically and reasonably develop single chiral drugs with low toxicity and high efficiency. Among them, high performance liquid chromatographic techniques based on chiral stationary phases (CSPs) has become one of the most attractive methods used to evaluate the enantiomeric purity of single-enantiomers compound of pharmacological relevance. In this work, pillar[5]arene functionalized with L- and D-histidine, respectively, were modified on the surface of mesoporous silica as novel chiral stationary phases called L/DHis-BP5-Sil. Notably, L/D-histidine had the characteristics of low steric hindrance and easy derivatization. Although the π-π interaction of imidazole group was weaker than that of benzene ring, the benzene ring bonding imidazole-conjugated ring in the structure produced better enantioseparation effect. The results showed that L/DHis-BP5-Sil can separate a variety of complex structural enantiomers with excellent reproducibility, thermal stability and separation performance. Hence, the unique advantage of the highly selective separation of L/DHis-BP5-Sil provides new insights into the enantioseparation field.

Sensitive and validated UPLC-MS/MS method for the identification and characterization of forced degradation products for felodipine

AbstractA rapid, stability indicating reverse phase liquid chromatographic method was developed for the determination of purity of Felodipine in active pharmaceutical substance form in the presence of its impurity and its degradation products. To develop the method which is also compatible to liquid chromatographic mass spectroscopic technique. The developed method is also used to determine the assay of Felodipine in bulk drug form. The drug is subjected to various stress conditions like acidic, basic, oxidation, UV light and thermal conditions. Considerable degradation was observed during base hydrolysis. Two degradation products were identified. The Waters Acquity UPLC BEH C18, 2.1 × 100 mm, 1.7 µm Column was used to achieve chromatographic separation. The gradient conditions, diluent and injection volume were optimized to achieve the acceptable resolution between impurities and its degradation products from Felodipine and to get good peak shapes. The masses were determined for main compound and its identified degradation products. Further, the characterization studies for main compound and its degradation products were performed using LCMSMS Q-TOF.

Does the Invasive Heracleum mantegazzianum Influence Other Species by Allelopathy?

Heracleum mantegazzianum is an invasive species in middle Europe. The mode of action of its invasiveness is still not known. Our study focuses on observation of potential allelopathic influence by the production and release of phytochemicals into its environment. Plant material was collected four times within one season (April, May, June, July 2019) at locality Lekárovce (eastern Slovakia) for comparison of differences in composition and potential allelopathy. Water extracts from collected samples were used for different biological assays. The total phenols and flavonoids were determined spectrophotometrically. The profile and content of phenolic components, including coumarins, were determined by two techniques of liquid chromatography along with in vitro evaluation of the free radical scavenging activity of extracts (DPPH, Hydroxyl, Superoxide, and FRAP). The changes in composition in extracts in different seasonal periods were evident as well as potential phytotoxic activity in some concentrations on specific model plants. The slight antioxidant activity was noted. The invasiveness of the current species could be supported by the excretion of its phytochemicals into its surroundings and by different modes of action influencing living organisms in its environment.

Simultaneous estimation of mometasone furoate and olopatadine hydrochloride by reversed‐phase high‐performance liquid chromatography

AbstractThe simultaneous determination of Mometasone furoate (MOM) and Olopatadine hydrochloride (OLO) in a combined dose has been developed and validated using a specific, precise, accurate, fast, reliable, and economical high‐performance liquid chromatography technique. Methanol:water:acetonitrile (20:25:55, v/v/v) was used as the mobile phase during the separation. The procedure was performed using a low‐pressure gradient elution on the reversed‐phase Phenomenex C18 column. At 238 nm, separated components were densitometrically measured. The flow rate was fixed at 1.0 mL/min with a continuous run up to 10 min, while the retention time was located near about 3.2 and 6.1 min for OLO and MOM, respectively. The method was validated for Linearity and range, precision, reproducibility, specificity, accuracy, limit of detection, limit of quantification, and robustness as per the International Council for Harmonization Q2(R1) guideline. MOM and OLO regression coefficients (r2) were found to be 0.9994 and 0.9997, over the range of 2.5–15 and 33.25–199.5 µg/mL, respectively. MOM and OLO percentage recoveries were measured to be 99.49 ± 0.14 and 99.98 ± 0.22, respectively. The method can be successfully applied for routine analysis of the quantitative determination of MOM and OLO in a combined dose.