Reversed-phase High-performance Liquid Research Articles

Two Novel Angiotensin-Converting Enzyme (ACE) Inhibitory and ACE2 Upregulating Peptides from the Hydrolysate of Pumpkin (Cucurbita moschata) Seed Meal.

Pumpkin (Cucurbita moschata) seed meal (PSM), the major byproduct of pumpkin seed oil industry, was used to prepare angiotensin-converting enzyme (ACE) inhibitory and angiotensin-converting enzyme 2 (ACE2) upregulating peptides. These peptides were isolated and purified from the PSM hydrolysate prepared using Neutrase 5.0 BG by ultrafiltration, Sephadex G-15 column chromatography, and reversed-phase high-performance liquid chromatography. Two peptides with significant ACE inhibition activity were identified as SNHANQLDFHP and PVQVLASAYR with IC50 values of 172.07 and 90.69 μM, respectively. The C-terminal tripeptides of the two peptides contained Pro, Phe, and Tyr, respectively, and PVQVLASAYR also had Val in its N-terminal tripeptide, which was a favorable structure for ACE inhibition. Molecular docking results declared that the two peptides could interact with ACE through hydrogen bonds and hydrophobic interactions. Furthermore, the two peptides performed protective function on EA.hy926 cells by decreasing the secretion of endothelin-1, increasing the release of nitric oxide, and regulating the ACE2 activity. In vitro simulated gastrointestinal digestion showed the two peptides exhibited good stability against gastrointestinal enzyme digestion. In conclusion, PSM is a promising material for preparing antihypertensive peptides.

Stability-Indicating HPLC Method for Determination of Ibuprofen and Famotidine Degradation Products.

A new stability-indicating high-performance liquid chromatographic method for the quantitative determination of ibuprofen and famotidine degradation products in combined pharmaceutical products was developed and validated. The current aim of this study is to develop a rapid, accurate and robust analytical stability indicating impurity method that can separate ibuprofen, famotidine and their related impurities by using a reversed-phase high-performance liquid chromatography. A Zorbax SB-Phenyl column (4.6 × 150mm2, 5-μm particle size) with mobile phase containing phosphate buffer solution with a pH value of 3.0 and acetonitrile was used. The flow rate was 0.8mL/min and the analytes were detected by UV detector at 265nm. The retention times of ibuprofen and famotidine were 18.43 and 5.14min, respectively. This method was validated to confirm specificity, linearity, sensitivity (limit of detection and limit of quantitation), precision, accuracy, robustness and sample stability according to the International Conference on Harmonization guidelines. Studies have been completed and reported with two active substances in the combined dosage form and seven impurities in total. There is no method in the literature that simultaneously distinguishes and quantitatively analyzes both active substances and degradation products.

Pharmacokinetics of famotidine in goats after intravenous administration.

There is currently limited pharmacokinetic data for the use of famotidine in goats for treatment and prevention of abomasal ulceration. The objective of this study was to determine the pharmacokinetic parameters after a single intravenous administration of famotidine (0.6 mg/kg). Famotidine was administered to six healthy goats and plasma samples were collected over a 24-h period. The famotidine concentration was measured using reverse phase high-performance liquid chromatography (HPLC). Non-compartmental analysis was then used to determine the pharmacokinetic parameters. The maximum plasma concentration was estimated at 5476.68 ± 1530.51 ng/mL and elimination half-life was estimated at 18.455 ± 13.26 min. The mean residence time was determined to be 19.85 ± 12.14 min with the apparent volume of distribution being estimated at 321.924 ± 221.667. The area under the curve was determined to be 54230.08 ± 24947.6 min*ng/mL. Total exposure and elimination half-life were less than what has been reported in cattle and horses. Future research evaluating the pharmacokinetics of subcutaneous administration and looking at the pharmacodynamics of famotidine in goats is needed to determine the effectiveness of famotidine on raising pH levels of the abomasum.

Determination of Bovine Lactoferrin in Powdered Infant Formula and Adult Nutritionals by Heparin Affinity Extraction and Reverse-Phase High Performance Liquid Chromatography/Ultraviolet Detection (HPLC/UV): Single-Laboratory Validation, First Action 2021.10.

Infant formulas, pediatric and adult nutritional products are being fortified with bovine lactoferrin (bLF) due to its beneficial impacts on immune development and gut health. Lactoferrin supplementation into these products requires an analytical method to accurately quantify the concentrations of bLF to meet global regulatory and quality standards. To develop and validate a lactoferrin method capable of meeting the AOAC Standard Method Performance Requirements (SMPR requirements 2020.005). Powder formula samples are extracted using warm dibasic phosphate buffer, pH 8, then centrifuged at 4 °C to remove insoluble proteins, fat, and other solids. The soluble fraction is further purified on a HiTrap heparin solid-phase extraction column to isolate bLF from interferences. Samples are filtered, then analyzed by LC-UV using a protein BEH C4 analytical column and quantitated via external calibrant. The limit of quantitation (2 mg/100g), repeatability (2.0-4.8% RSD), recovery (92.1-97.7%) and analytical range (∼4-193 mg/100g) all meet the method requirements as stated in SMPR 2020.005 for lactoferrin. The reported single lab validation results demonstrate the ability of this lactoferrin method to meet or exceed the method performance requirements to measure soluble, intact, non-denatured bLF in infant and adult nutritional powder formulas. The use of a heparin affinity column to isolate lactoferrin from bovine milk products combined with a selective analytical chromatographic column provides suitable analyte specificity without requiring proprietary equipment or reagents.

RP-HPLC-CAD method for the rapid analysis of lipids used in lipid nanoparticles derived from dual centrifugation

The use of lipids as suitable excipients for drug carrier systems has been established for years. Liposomes or lipid nanoparticles (LNPs) in general have been shown capable of delivering both hydrophilic and hydrophobic drugs. The Covid-19 pandemic and the resulting vaccines have significantly increased interest in the potential for these lipid-based systems, which can carry different types of therapeutic RNAs. LNPs used for the transfection of RNA are usually a multi-component mixture of phospholipids and other lipids. Essential components are positively charged or ionizable lipids such as DOTAP or SM-102, but also uncharged helper lipids such as cholesterol, DOPE, DSPC, DMG-PEG2000 or DSPE-PEG2000. Due to the differences in charge, simultaneous detection is a challenge. Here, we present a reversed-phase high-performance liquid chromatography charged-aerosol-detector method (RP-HPLC-CAD method) using a C-18 column for the simultaneous determination of charged and uncharged lipids. Our method has been validated according to the ICH-Q2 (R2) guideline for accuracy, precision, specificity and working range, including the limit of detection (LOD) and quantification (LOQ), as well as the calibration range. We were able to show satisfactory results in both precision and accuracy. The working range also shows great potential with a calibration range from 9.375 to 1000 μg/ml, LODs <1.85 μg/ml and LOQs <6.16 μg/ml. This method represents a fast and reproducible procedure for quantifying the lipids mentioned. In combination with the novel approach for the production of LNPs using dual centrifugation (DC), it offers the possibility of extremely rapid production of RNA-loaded LNPs, and the immediate analysis for their lipid components.

Variations in colostrum metabolite profiles in association with sow parity

Abstract Information about the full spectrum of metabolites present in porcine colostrum and factors that influence metabolite abundances is still incomplete. Parity number appears to modulate the concentration of single metabolites in colostrum. This study aimed to 1) characterize the metabolome composition and 2) assess the effect of parity on metabolite profiles in porcine colostrum. Sows (n = 20) were divided into three parity groups: A) sows in parity 1 and 2 (n = 8), B) sows in parity 3 and 4 (n = 6), and C) sows in parity 5 and 6 (n = 6). Colostrum was collected within 12 h after parturition. A total of 125 metabolites were identified using targeted reversed phase high-performance liquid chromatography tandem mass spectrometry and anion-exchange chromatography-high resolution mass spectrometry. Gas chromatography additionally identified 19 fatty acids (FA). Across parities, colostrum was rich in creatine and creatinine, 1,3-dioleyl-2-palmitatoylglycerol, 1,3-dipalmitoyl-2-oleoylglycerol and sialyllactose. Alterations in colostrum concentrations were found for 8 metabolites among parity groups (P &amp;lt; 0.05) but effects were not linear. For instance, colostrum from parity group C comprised 75.4% more valine but 15.7, 34.1 and 47.9% less citric, pyruvic and pyroglutamic acid, respectively, compared to group A (P &amp;lt; 0.05). By contrast, colostrum from parity group B contained 39.5% more spermidine than from group A (P &amp;lt; 0.05). Of the FA, C18:1, C16:0 and C18:2 n-6 were the main FA across parities. Parity affected four FA (C18:3n3, C14:1, C17:0ai and C17:1), including 43.1% less α-linolenic acid (C18:3n3) in colostrum from parity group C compared to groups A and B (P &amp;lt; 0.05). Signature feature ranking identified 1-stearoyl-2-hydroxy-sn-glycero-3-phosphatidylcholine and the secondary bile acid hyodeoxycholic acid as the most discriminative metabolites, showing a higher variable importance in the projection score in colostrum from parity group A than from groups B and C. Overall, results provided a comprehensive overview about the metabolome composition of sow colostrum. The consequences of the changes in colostrum metabolites with increasing parity for the nutrient supply of the piglets should be investigated in the future. The knowledge gained in this study could be used to optimize feeding strategies for sows.

Optimising the recovery of phenolic compounds and antioxidant activity from orange peels through solid-state fermentation

It is widely recognised that orange peels contain a considerable quantity of phenolics, primarily in the form of glycosides. The process of fermentation holds potential as a viable method for extracting phenolic compounds and facilitating their biotransformation into novel metabolites. The aim of this study was to assess the enhanced release of phenolic compounds through the process of solid-state fermentation of orange peels using microorganisms. Following a 6-day incubation period, the methanol extract obtained from the sample fermented with starter Banh men exhibited the highest concentration of total phenolic compounds (17.57 ± 0.34 mg GAE/g DW) and demonstrated the most significant DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging activity (55.03%). The Reverse Phase High Performance Liquid Chromatography (RP-HPLC) analysis revealed that the predominant phenolic compounds in all fermented samples were flavonoid aglycones, specifically naringenin, hesperetin, and nobiletin. Conversely, in the unfermented orange peels, the major compound observed was the glycoside derivative hesperidin.

Different Detection Strategies of Pediocin-Like Produced by Pediococcus pentosaceus.

In this study, Pediococcus pentosaceus C-2-1 and C23221 contained genes encoding penocin and pediocin PA-1, mined by antiSMASH. The penocin structural gene pedA from Pediococcus pentosaceus C-2-1 was successfully expressed in Escherichia coli BL21. The presence of a 6.5kDa recombinant penocin was confirmed by Tricine-SDS-PAGE, and the specific activity increased by 1.54-fold. The bacteriocins produced by Pediococcus pentosaceus C23221 were purified using acetic ether extraction, Sepharose Fast Flow, Sephadex G-25 gel chromatography, and reversed-phase high-performance liquid chromatography (RP-HPLC); the amino acid sequence of this bacteriocin was identical to pediocin PA-1 by high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS), which confirmed the expression of pediocin PA-1 gene; and the specific activity increased by 24.39-fold. The heterologous expression and purification of bacteriocins have proved the expression of pediocin-like produced by Pediococcus pentosaceus. This provides a theoretical basis for the subsequent development and application of pediocin-like.

Retention mechanisms of amitriptyline and its impurities on amide, amino, diol, and silica columns in hydrophilic interaction liquid chromatography.

Hydrophilic interaction liquid chromatography (HILIC) has been widely applied to challenging analysis in biomedical and pharmaceutical fields, bridging the gap between normal-phase high-performance liquid chromatography and reversed-phase high-performance liquid chromatography (RP-HPLC). This paper comprehensively explores the retention mechanisms of amitriptyline and its impurities A, B, C, D, F, and G on amide, amino, diol, and silica columns. Dual HILIC/RP-HPLC retention mechanisms were developed, and transitional points between HILIC and RP-HPLC mechanisms were calculated on amide, diol, and silica columns. Adsorption and partition contributions to overall retention mechanisms were evaluated using Python software in HILIC and RP-HPLC regions. The cation exchange mechanism dominates overall retention for ionized analytes in the silica column (R2>0.995), whereas the retention of ionized analytes increases with pH. Impacts of acetonitrile content, buffer ionic strength, and pH, along with their interactions on the retention of ionized analytes in the silica column, were determined using the chemometric approach. Acetonitrile content showed the most significant impact on the retention mechanisms. These findings highlight that a detailed investigation into retention mechanisms provides notable insights into factors influencing analyte retention and separation, promising valuable guidance for future analysis.

A stability-indicating method development and validation for the determination of related substances in novel synthetic decapeptide by HPLC.

In the present scenario, peptide is an emerging field of research having vast therapeutic applications. Diverse impurities may rise from various stages of the synthesis process and storage of the peptides. Because these contaminants may have an impact on the therapeutic safety and effectiveness of peptides in their approaching applications, they must be identified and carefully monitored. Considering the pharmaceutical importance of the extent of peptides, we were motivated to synthesize a decapeptide and establish a novel gradient reversed-phase high-performance liquid chromatography (RP-HPLC) method for its analysis along with efficient separation of its six related impurities. Different buffers, organic modifiers, and columns were used in the tests for good separation of these impurities. To establish a stability-indicating method, a stress study was also conducted. The International Conference on Harmonization (ICH) guidelines have been followed for validation of the developed analytical method. The validated method revealed sufficient accuracy, specificity, linearity, robustness, precision, and high sensitivity for its intended use. The proposed method could be appropriate for routine analysis and stability assessment of the decapeptide, which might be useful for further scientific investigation.

Novel RP-HPLC method for estimation of a newly developed combination of tizanidine and etoricoxib in rat plasma: Eight criteria for greens evaluation.

A novel environmentally friendly reversed-phase high-performance liquid chromatography (RP-HPLC) method has been effectively validated for simultaneously measuring a prospective conjunction of tizanidine (TIZ) and etoricoxib (ETC), the combined medicine, in rat plasma. The technique employs diclofenac potassium as the internal standard, guaranteeing dependable and precise outcomes. This study aimed to assess the impact of the suggested combination therapy on treating inflammation resulting from rheumatoid arthritis (RA) in a rat model. The procedure was performed using an Agilent series 1200 model HPLC apparatus. The chromatographic conditions consist of isocratic elution mode, C18 column with dimensions of 150 mm × 4.6 mm × 5 µm, flow rate of 1.5 mL/min, wavelength of 230 nm, temperature of 50°C, and injection volume of 10 µL. The elution was performed using a mobile phase consisting of a phosphate buffer with a pH of 3.5 and acetonitrile in a ratio of 80:20 v/v. Calibration curves were conducted for TIZ and ETC within the 1-50 µg/mL range, demonstrating linear trends with R2 values over 0.999. The effectiveness and eco-friendliness of the proposed method were evaluated using eight separate environmentally conscious metrics. The addition of TIZ and ETC to arthritic rodents amplified these effects significantly. Furthermore, TIZ and ETC significantly reduced serum levels in arthritic rodents, and safety investigations revealed normal complete blood count, liver, and renal functions. TIZ and ETC appear to have antiarthritic, anti-inflammatory, and safe combinations, making them viable future treatment options for RA that are also safe and efficacious. Following validation by United States Food and Drug Administration(US-FDA) rules, all goods met the criteria.

Novel post-functionalized polymer microspheres containing capsaicin as reversed-phase chromatography stationary phase separation for hydrophilic compounds

Here, we created for the first time that highly stable polymer microspheres copolymerized with capsaicin derivative, divinyl benzene, and N-(Hydroxymethyl)acrylamide could be efficient for reversed-phase high-performance liquid chromatography (RP-HPLC) by using a simple “one-pot cooking” method, which had the potential to be produced in large quantities. Then, the spheres were post-functionalized with two different monomers, N-vinyl formamide and 4-acrylomorpholine by double coating, which had ideal mechanical strength and efficiency as stationary phase. In order to reach best separation condition, the effects of buffer concentration, pH, column temperature, and mobile phase polarity on the retention rate were studied. Specifically, the interaction mechanism showed that the stationary phase had hydrophobic and electrostatic interaction with the water-soluble vitamins. It is of significant interest that all columns had excellent precision and accuracy (RSD < 4 %). Taken together, this study played a specific role in promoting the development of a new reverse-phase mode for separating hydrophilic compounds.

Comparison between Conventional Ageing Process in Barrels and a New Rapid Aging Process Based on RSLDE: Analysis of Bioactive Compounds in Spirit Drinks

“Aging” is a practice that allows alcoholic beverages to mature and gives them particular flavors and colors. In this context, oak or durmast wooden barrels are used in this process, thus providing different types of aging. This conventional process produces a slow enrichment of organic compounds in the spirit inside the barrels. Organic substances present in the internal part of the barrels slowly undergo the phenomenon of extraction by the liquid phase (solid–liquid extraction). In this work, a new procedure based on rapid solid–liquid dynamic extraction (RSLDE) was used to evaluate the potential of obtaining the effects of aging in spirits in shorter times than conventional methods. For this purpose, a comparison between two solid–liquid extraction techniques, RSLDE and conventional maceration, was made. Four water/ethanol 60:40 (v/v) model solutions were prepared and put in contact with medium-toasted chips using the two extraction procedures (conventional and non-conventional) and determining dry residue and total polyphenol content. Reversed phase high-performance liquid chromatography (RP-HPLC) analyses allowed the identification and quantification of furfural, ellagic acid and phenolic aldehydes (vanillin, syringaldehyde, coniferaldehyde and sinapaldehyde). The aging procedure with medium-toasted chips was tested on a young commercial grappa using maceration and RLSDE.

Chronic exposures to cholinesterase-inhibiting pesticides adversely affects the health of agricultural workers in India

Biomonitoring of pesticide exposure has become a public concern because of its potential health effects. The present study investigated the acetylcholinesterase (AChE) inhibitory levels and their associated health effects in agricultural areas in Telangana, India. This cross-sectional included 341 exposed participants and 152 control participants from agricultural areas. A structured questionnaire was completed and blood and urine samples were collected to measure pesticides, dialkyle phosphate (DAP) metabolites, and AChE activity using liquid chromatography-tandem mass spectrometry and reversed-phase high-performance liquid chromatography. twenty-eight pesticides were detected in blood samples at concentrations ranging 0.42-45.77 ng/mL. Six DAP metabolites were also measured in urine, and all DAP metabolites were significantly higher in the exposed group. AChE activity is significantly reduced in individuals exposed for >10 years, raising concerns regarding possible neurological disorders. These results emphasise the urgent need to investigate the health effects of pesticides exposure, especially in agriculture.

Analytical Method Development and Validation of Brivaracetam in API and Marketed Formulation by RP-HPLC

A rapid and precise reverse phase high performance liquid chromatographic method has been developed for the validated of brivaracetam in its pure form as well as in tablet dosage form. Chromatography was carried out on a Symmetry ODS RP C18,5mm, 15mm x 4.6mm column using a mixture of phosphate buffer: methanol: acetonitrile (30:35:35% v/v) as the mobile phase at a flow rate of 1.0ml/min, the detection was carried out at 285 nm. The retention time of the brivaracetam was 2.183. The method produces linear responses in the concentration range of 60-140μg/ml of brivaracetam. The method precision for the determination of assay was below 2.0%RSD. The method was found to be sensitive, accurate and precise useful in the quality control of bulk and pharmaceutical formulations.

Updated component analysis method for naturally occurring sophorolipids from Starmerella bombicola

Sophorolipids (SLs) are promising glycolipid biosurfactants as they are easily produced and functional. SLs from microorganisms are comprised of mixtures of multiple derivatives that have different structures and properties, including well-known acidic and lactonic SL (ASLs and LSLs, respectively). In this study, we established a method for analyzing all SL derivatives in the products of Starmerella bombicola, a typical SL-producing yeast. Detailed component analyses of S. bombicola products were carried out using reversed-phase high-performance liquid chromatography and mass spectrometry. Methanol was used as the eluent as it is a good solvent for all SL derivatives. With this approach, it was possible to not only quantify the ratio of the main components of ASL, LSL, and SL glycerides but also confirm trace components such as SL mono-glyceride and bola-form SL (sophorose at both ends); notably, this is the first time these components have been isolated and identified successfully in naturally occurring SLs. In addition, our results revealed a novel SL derivative in which a fatty acid is bonded in series to the ASL, which had not been reported previously. Using the present analysis method, it was possible to easily track compositional changes in the SL components during culture. Our results showed that LSL and ASL are produced initially and that SL glycerides accumulate from the middle stage during the fermentation process.Key points• An easy and detailed component analysis method for sophorolipids (SLs) is introduced.• Multiple SL derivatives were identified different from known SLs.• A novel hydrophobic acidic SL was isolated and characterized.Graphical

Exploring the phytochemical and biological properties of Salsola foetida: a promising wild plant from Southeastern Algeria

ABSTRACT This study presents an initial exploration of the phytochemical composition and biological properties of Salsola foetida, a wild plant native to southeastern Algeria. The investigation encompassed an analysis of the biochemical content, phytochemical profile, and bioactivity of the plant’s aerial parts. The biomass of S. foetida was found to comprise 51.2 ± 0.4% ash, with elemental analysis revealing the presence of carbon, oxygen, calcium, sodium, chlorine, magnesium, potassium, and sulfur. Carbohydrates were identified as the predominant constituents, surpassing the levels of proteins and lipids. Phytochemical screening, coupled with Fourier Transform Infrared (FT-IR) analysis, confirmed the presence of various secondary metabolites, including alkaloids and phenols. Reversed-phase high-performance liquid chromatography (RP-HPLC) analysis further delineated a spectrum of phenolic compounds, with rutin emerging as the predominant compound at 1.59 µg/ml. Quantification revealed a noteworthy phenolic content of 67.1 ± 0.2 µg GE/mg ED. The extract exhibited robust radical scavenging effects, with the radical 50% inhibitory concentration (IC50) being 61.8 ± 0.2 μg/ml, along with protective effects against H2O2-induced hemolysis and the ability to reduce ferric ions. Additionally, the extract demonstrated anti-inflammatory, antibacterial, and antidiabetic activities. Notably, it exhibited considerable sunscreen properties, boasting a sun protected factor (SPF) value of 21 ± 1. Overall, S. foetida presents promising antioxidant activity and a spectrum of potential biological activities, underscoring its significance as a novel antioxidant candidate for applications in animal nutrition, medicine, and natural product research.

Validation of High-Performance Liquid Chromatography Method for the Determination of Doxorubicin in Proliposomal Drug Delivery System Formulation

The objective of this study develop a novel proliposome formulation containing Doxorubicin (Dox) and was to validate sensitive and selective reversed-phase high-performance liquid chromatographic (HPLC) method for the evaluation of Dox concentrations of proliposome formulation. The samples were chromatographed on C18 column (Zorbax Eclipse Plus 5µm 4.6 x 250 mm) using a mobile phase with Sodium Lauryl Sulphate solution:Acetonitrile (%50:%50) and detected 254 nm. Linearity was confirmed in the concentration range 10.0–75.0 µg/mL. Specificity, linearity, working range, LOD, LOQ, accuracy, precision, robustness and system suitability studies were done from HPLC validation parameters. Liposome formulation containing Dox was developed by pH gradient method then proliposome formulation was developed with lyophilisation technique. The developed HPLC method, the encapsulation capacity (EE%) was found to be 90%±0.5 and the drug loading capacity (DL%) was found to be 100.0%±0.3. In addition, in vitro release studies and stability study results were evaluated with validated HPLC method. It was observed that developed Dox-proliposome formulation increased Dox release at pH 5.5, pH 6.5 and pH 7.5 by 23.9%, 30.2% and 14.8%, respectively, compared to commercial product. The result of F2 test performed in pH 7.5 media was 51.4%. According to the results of the physicochemical tests performed within the stability studies, it was observed that there was no significant change at the end of 12 months. These results show that the HPLC method developed, and validation study performed are important and applicable in the development, characterization, in vitro release and stability studies of the novel proliposome formulation.

Therapeutic drug monitoring of six contraindicated/co-administered drugs by simple and green RP-HPLC-PDA; application to spiked human plasma

Therapeutic drug monitoring is an important clinical testing of the drugs to monitor their concentrations in plasma in order to guarantee their optimal impact, and to avoid any side effects resulting from drug-drug interactions. A green reversed-phase high-performance liquid chromatographic method using a photodiode array detector (RP-HPLC-PDA) was developed for the simultaneous determination of three carbapenem antibiotics (Imipenem, ertapenem, and meropenem) with the co-formulated drug (cilastatin) and contraindicated drugs (probenecid and warfarin) in spiked human plasma. The separation was achieved at 25 °C using a gradient elution of a mixture of mobile phase A: methanol and mobile phase B: phosphate buffer (pH 3.0). The photodiode array detector was adjusted at 220 nm. Bioanalytical method validation was carried out as per the FDA guidelines, and the method showed good linearity ranges for the six drugs that included their Cmax levels along with low limits of quantification. Based on the results, the method was found to be accurate and precise; with high % recovery and good % RSD, respectively. The method was successfully applied to spiked human plasma, signifying a good potential to be implemented in future TDM studies of these drugs when co-administered together.

A novel, high throughput, and low cost method for the detection of 40 amino acids relevant to inborn errors of metabolism in under 60 minutes using reverse phase high performance liquid chromatography

A novel, high throughput, and low cost method for the detection of 40 amino acids relevant to inborn errors of metabolism in under 60 minutes using reverse phase high performance liquid chromatography