High-performance Liquid Chromatographic Method For Analysis Research Articles

Validation of HPLC and TLC analytical methods to determine radiochemical purity of 99mTc-cAbVCAM1-5, a new experimental radiotracer

Cardiovascular diseases, including fatal myocardial infarctions from atheromatous plaques, are the primary global mortality cause. Detecting stenotic atheromatous plaques is possible through coronary angiography, but vulnerable plaques with eccentric remodeling are undetectable with current diagnostic methods. Addressing this challenge, our group developed a radiopharmaceutical drug targeting vascular cell adhesion molecule 1 (VCAM-1), radiolabeled with technetium-99m. Given the absence of a monograph in the European Pharmacopoeia, and in order to draft the investigational medicinal product documentation, analytical methods had to be validated by high performance liquid chromatography (HPLC) and thin layer chromatography (TLC) to determine the radiochemical purity (RCP) of 99mTc-cAbVCAM1–5. This study therefore presents the results of the validation of analytical methods obtained in this context. The method validation followed the European Association of Nuclear Medicine (EANM) recommendations adapted from ICH Q2(R1), ensuring conformity with specificity, accuracy, repeatability and intermediate precision, linearity, robustness, quantification limit (LoQ), and range criteria. Regarding the results of specificity, both HPLC and TLC methods demonstrated excellent separation of 99mTc-cAbVCAM1–5 from impurities 99mTcO4-. Accuracy results indicated recovery percentages within the range of 99.52–101.40% for the HPLC and 99.51–101.97% for TLC, ensuring reliable measurements for each concentration of 99mTcO4-. Precision of the methods was validated by assessing repeatability and intermediate precision. Linearity was determined over the usual concentrations range and the correlation coefficient was greater than 0.99 for both methods. The limit of quantification was measured by diluting the 99mTcO4- to obtain a signal-to-noise ratio of around 10:1. Under these conditions, we obtained an LOQ of 2.10 MBq/mL for HPLC and 2Mbq/mL for TLC. In conclusion, the analytical methods developed in this study comply with EANM recommendations. This therefore allows us to correctly assess the radiochemical purity of 99mTc-cAbVCAM1–5, a new radiotracer targeting inflammation in vulnerable plaques.

Green Analytical HPLC Method Development of Acyclovir Loaded Floating Raft Formulation in Spiked Rabbit Plasma

Objective: The need of this investigation is to design eco-friendly, sensitive, and precise bioanalytical high-performance liquid chromatography (HPLC) techniques that leverage green analytical tools such as green analytical procedure index (GAPI), analytical eco scale (AES), and analytical greenness metric (AGREE) to analyze ACV-spiked rabbit plasma and ACV-loaded floating raft formulation (FRF) because The literature survey revealed insufficient data for the HPLC approach to FRF. Method: Methods involving plasma spikes mirroring the in-vivo models provide insights into potential real-life scenarios and the functionality of floating raft formulations loaded with ACV. The Design Expert tool optimized critical process parameters and identified significant factors influencing the chromatographic technique. Results: The CCD was used to optimize the flow rate (0.6 mL/min) and buffer solvent ratio (99:1) for separation. The C18 column (250 X 4.6 mm) was utilized to achieve the elution of ACV. The developed method was thoroughly validated through ICH guidelines. The ACV, lower limit of detection (LLoD), and lower limit of quantitation (LLoQ) retention times were established at 2.3 minutes, 15, and 20 ng/mL, respectively. Discussion: In summary, the study demonstrated the exceptional performance sensitivity, specificity, and robustness of the bioanalytical method. The method proved highly effective in quantifying ACV in plasma samples in terms of revalidatability, transferability, reproducibility, and the product development cycle. The developed method proves that using both design of experiments (DoE) and green analytical chemistry together creates a valid, eco-friendly, and reliable way to analyze the making of an ACV-loaded floating raft formulation.

High-Performance Liquid Chromatography (HPLC) Method Validation for Identifying and Quantifying Rebamipide in Ethosomes.

Introduction The research aimed to develop a robust, high-performance liquid chromatography (HPLC) analytical method for the quantitative assessment of rebamipide encapsulated in ethosomes. Rebamipide, a quinolinone derivative, holds promise as a therapeutic agent for dry eye, but challenges such as low bioavailability and vision clouding post-installation have prompted innovative approaches. Encapsulation in ethosomes, lipid-based nanovesicles, offers a potential solution to enhance ocular bioavailability. Materials and methods The study focused on creating a specific, linear, accurate, precise, and robust HPLC method, addressing entrapment efficiency (%EE), drug content, and drug release of rebamipide in prepared ethosomes. Statistical validation followed International Conference of Harmonization (ICH) specifications. The method's parameters were evaluated within a concentration range of 4-24 µg/ml, with recovery rates indicating accuracy and low % relative standard deviation (RSD) values confirming precision. Limits of detection (LOD) and quantification (LOQ) for rebamipide were determined. Results After preparing the ethosome dosage form by film hydrating method for rebamipide, the rebamipide entrapment efficiency in ethosomes was established at 76% ± 7, while the drug content was found to be 93% ± 6. The drug release process demonstrated zero-order kineticsand five different models of kinetics were applied for a comprehensive analysis. The method exhibited excellent system suitability, specificity, and linearity. Recovery rates for rebamipide ranged from 90% to 100%, and repeatability was confirmed by low %RSD values. The LOD and LOQ for rebamipide were determined to be 1.04 μg/mL and 3.16 μg/mL, respectively. Conclusion The developed HPLC method proved suitable for the quantitative determination of rebamipide in ethosomes, offering rapid and accurate analysis. The results underscore the method's specificity, accuracy, and precision within the specified concentration range. Overall, the validated method contributes to the advancement of ocular drug delivery systems, providing a reliable analytical tool for pharmaceutical research.

Implementation of Quality by Design Approaches for Development and Validation of Reverse-Phase High-Performance Liquid Chromatography Assay Method for Determination of Glycyrrhizin in Nanoformulation.

Glycyrrhizin (GL) is the principal constituent of Glycyrrhiza glabra, having antiallergic, anticancer, anti-inflammatory, and antimicrobial action. The reverse-phase high-performance liquid chromatography (RP-HPLC) analytical method was used to quantitatively estimate GL in a nanoformulation and validated as per International Conference on Harmonization Q2 (R1) standards. A stationary phase of the C18-HL reversed-phase column and a mobile phase of acetonitrile and water were used for effective elution. The chromatographic conditions of RP-HPLC were optimized utilizing a quality-by-design approach to accomplish the required chromatographic separation of GL from its nanoformulation with minimal experimental runs. Optimized RP-HPLC conditions for the assay method consist of acetonitrile (41%) and water, pH 1.8, balanced with phosphoric acid (0.1%) as a mobile phase with a flow rate of 1 mL/min. The retention time was found at 7.25 min, and method validation confirmed its sensitivity, preciseness, accuracy, and robustness.

Simultaneously characterization of multiple constituents in Valeriana jatamansi Jones using an online supercritical fluid extraction-high-performance liquid chromatography/supercritical fluid chromatography-mass spectrometry system.

Valeriana jatamansi Jones is a commonly used traditional Chinese medicine, boasting rich effective compositions with versatile chemical structures and wide polarity, including iridoids, chlorogenic acid, and flavonoids. Previous reports indicate that conventional high-performance liquid chromatography (HPLC) analytical methods have proven inefficient performance in comprehensively characterizing components in Valeriana jatamansi. In the present study, a hybrid online analytical platform combining supercritical fluid extraction with both conventional HPLC separation (reverse phase) and supercritical fluid chromatography (normal phase) has been established and validated. This system can provide online extraction with two different chromatographic separation modes to increase separation ability and has been connected to a mass spectrometer to acquire high-resolution mass spectrometry data. Then, the online platform was applied to screening components in Valeriana jatamansi. A total of 117 compounds were identified, including five lignans, 18 organic acids, six flavonoids, and 88 iridoids. Thirty-three compounds were reported from Valeriana jatamansi for the first time. These results enrich our understanding of the components of Valeriana jatamansi and prove that the developed online platform in this study is a robust approach for accelerating working efficiency in comprehensively analyzing complicated samples.

Technology Transfer of a Validated RP-HPLC Method for the Simultaneous Estimation of Andrographolide and Paclitaxel in Application to Pharmaceutical Nanoformulation.

Many analytical methods are reported for simultaneous estimation of pharmaceutical dosages form. However, only a few are reproducible at an industrial scale. The proposed research aims to establish a technology transfer (TT) protocol between two laboratories (Lab-X, originator) with binary and (Lab-Y, receiver) with quaternary high-performance liquid chromatography (HPLC) system. Thus, utilizing reverse-phase HPLC (RP-HPLC), a robust, sensitive and repeatable analytical method has been developed, validated and TT between two laboratories for simultaneous estimation of Andrographolide (AG) and Paclitaxel (PTX). The method has been developed on a Phenomenex Luna C18 column (150 x 4.6, 5) sustained at 40°C and validated under the International Conference on Harmonisation (ICH) Q2 (R1) regulatory guideline and TT USP chapter 1224. The mobile phase consisted of MilliQ (pH = 3) and a combination of acetonitrile and methanol (1:1) in the ratio 50:50 with a flow rate of 0.45mL/min, linear gradient elution in both labs. The AG and PTX were detected on the PDA detector at 224 and 227nm wavelength with retention time of 4.5 ± 0.34 and 8.2 ± 0.02min and limit of detection was found 0.028 ± 0.004μg/mL, and 0.028 ± 0.0007μg/mL, whereas limit of quantification as 0.086 ± 0.011μg/mL and 0.088 ± 0.0014μg/mL respectively in both labs. Throughout, this approach we have proved that proposed method is repeatable in both labs, and it can be used to quantify AG and PTX in developed pharmaceutical nano-formulations.

Advancing posaconazole quantification analysis with a new reverse-phase HPLC method in its bulk and marketed dosage form.

Introduction: Posaconazole is a widely used antifungal drug, and its accurate quantification is essential for quality control and assessment of its pharmaceutical products. This study aimed to develop and validate a reverse-phase high-performance liquid chromatography (HPLC) analytical method for quantifying Posaconazole in bulk and dosage form. Methods: The HPLC method was developed and validated based on International Conference on Harmonisation (ICH) guidelines. The developed method was then applied to quantify Posaconazole in a marketed tablet formulation. The method's specificity, linearity, precision, accuracy, robustness, and stability were evaluated. Results: The developed HPLC method showed good linearity over a 2-20 μg/mL concentration range. The percentage recovery of Posaconazole from the bulk and marketed formulations was found to be 99.01% and 99.05%, respectively. The intra-day and inter-day precisions were less than 1%, and the method was stable under different conditions. The HPLC method was successfully applied to quantify Posaconazole in the marketed formulation. Conclusion: The developed and validated HPLC method is reliable and efficient for analyzing Posaconazole in bulk and dosage forms. The method's accuracy, precision, specificity, linearity, robustness, and stability demonstrate its effectiveness. The method can be used for the quality control and assessment of Posaconazole-containing pharmaceutical products.

RP-LC Method Development and Validation for Dasatinib Forced Degradation Study: Isolation and Structural Characterization by NMR and HRMS.

A reverse phase high-performance liquid chromatography (HPLC) method has been developed for the quantification of a typical drug Dasatinib (DST) and its related impurities in pharmaceuticals. Kinetex C18 (4.6 × 150mm, 5μm) column was used in the chromatographic separations, using buffer (1.36g of KH2PO4 in 1000mL of water, pH = 7.8; adjusted with diluted KOH solution) with solvent as acetonitrile and mode of elution as the gradient. The flow rate is 0.9mL/min, column oven temperature as 45°C and the overall gradient run time as 65min. The developed method was found to produce symmetric and good separation between the process-related and degradation impurities. Method optimization is achieved with photodiode array at 305nm over the concentration range of 0.5mg/mL and degradation studies were carried out under acidic, alkaline, oxidative, photolytic and thermal conditions to demonstrate the stability indicating capability of the method. Two major impurities were found in forced degradation studies in the HPLC analysis, the unknown, acid degradants were enriched and isolated by preparative HPLC, then characterized through high-resolution mass spectrometry, nuclear magnetic resonance spectroscopy and Fourier transform infrared spectroscopy. The unknown acid degradation impurity was showing Exact Mass of 521.11, molecular formula C22H25Cl2N7O2S and its chemical name as 2-(5-chloro-6-(4-(2-hydroxyethyl) piperazin-1-yl)-2-methylpyrimidin-4-ylamino)-N-(2-chloro-6-methylphenyl) thiazole-5-carboxamide. Another impurity (oxidative degradant) found as known DST N-oxide Impurity-L and its chemical name as 4-(6-((5-((2-chloro-6-methylphenyl) carbamoyl) thiazol-2-yl) amino)-2-methylpyrimidin-4-yl)-1-(2-hydroxyethyl) piperazine 1-oxide. The analytical HPLC method was further validated as per ICH guidelines.

Advancing posaconazole quantification analysis with a new reverse-phase HPLC method in its bulk and marketed dosage form

Introduction: Posaconazole is a widely used antifungal drug, and its accurate quantification is essential for quality control and assessment of its pharmaceutical products. This study aimed to develop and validate a reverse-phase high-performance liquid chromatography (HPLC) analytical method for quantifying Posaconazole in bulk and dosage form. Methods: The HPLC method was developed and validated based on International Conference on Harmonisation (ICH) guidelines. The developed method was then applied to quantify Posaconazole in a marketed tablet formulation. The method's specificity, linearity, precision, accuracy, robustness, and stability were evaluated. Results: The developed HPLC method showed good linearity over a 2-20 μg/mL concentration range. The percentage recovery of Posaconazole from the bulk and marketed formulations was found to be 99.01% and 99.05%, respectively. The intra-day and inter-day precisions were less than 1%, and the method was stable under different conditions. The HPLC method was successfully applied to quantify Posaconazole in the marketed formulation. Conclusion: The developed and validated HPLC method is reliable and efficient for analyzing Posaconazole in bulk and dosage forms. The method's accuracy, precision, specificity, linearity, robustness, and stability demonstrate its effectiveness. The method can be used for the quality control and assessment of Posaconazole-containing pharmaceutical products.

A Validated Reversed-phase High-performance Liquid Chromatography Analytical Method for the Analysis of Methylcobalamin in Bulk Drugs and T-Dosage Formulation

>The aim of the existing work is to develop and validate a reversed-phase high-performance liquid chromatography (RP-HPLC) technique for the quantitative determination of methylcobalamin in bulk and t formulations that is easy, rapid, precise, accurate, affordable, and sensitive. Proceeding a princeton (C18) column with dimensions (250 x 4.6 mm, 5 μ), the isocratic elution technique was used. The mobile buffer phase comprised water (pH 6.5, adjusted with sodium chloride) and methanol in the relation (55:45) v/v. It was shown that the methylcobalamin retention time was 2.022 minutes under ideal circumstances. The correlation coefficient (r2) for the 900–2400 mcg/mL methylcobalamin concentration range, which was used to verify the method’s linearity, was 0.9994. Methylcobalamin had a recovery rate of 99.98–100.01% and RSD of 2%. The marketed t formulation test was successfully completed with 99.86%. The proposed and validated approach underwent the accuracy, precision, specificity, linearity, and system suitability testing advised by the ICH. RP-HPLC was used in the market formulation.

Sensitive determination of pyrethroid insecticide residues in tea using a molecularly imprinted fiber array based on homemade solid-phase microextraction coatings

In this study, we proposed a homemade solid-phase microextraction fiber array based on molecularly imprinted polymer coatings. This sample pretreatment technique was used prior to high-performance liquid chromatography (HPLC) to identify pyrethroids, of a class of high-efficiency insecticides for controlling plant pests and diseases in agriculture. Findings revealed that the molecularly imprinted three-fiber array for solid-phase microextraction significantly increased the extraction capacity by 2.1 to 3.5 times compared with a single molecularly imprinted fiber, and it also increased the extraction capacity by 2.0 to 3.4 times compared with two different commercial fiber arrays. The imprinted fiber array extraction coupled with the HPLC analytical method was effective and sensitive in an aqueous solution. In addition, this combined method improved the extraction and screening capacities of pyrethroid insecticides. The detection limits of pyrethroid insecticides in tea samples were 0.16–0.33 μg/L with linear correlation coefficients of 0.9900–0.9994. The spiked recoveries were 72.74–119.66 %, with RSD (n = 3) below 14.53 %. Thus, this work provides an effective, sensitive, and practical method with good enrichment effects for analyzing and determining of multiple pyrethroids in tea samples.

Simultaneous quantification of dasatinib, nilotinib, bosutinib, and ponatinib using high-performance liquid chromatography-Photodiode array detection.

BackgroundDasatinib, nilotinib, and bosutinib, second‐generation tyrosine kinase inhibitors (TKIs), and ponatinib, a third‐generation TKI, are approved pharmaceuticals used in the treatment of chronic myeloid leukemia (CML). Although liquid chromatography‐tandem mass spectrometry assays for simultaneous quantification of the four TKIs in human serum have been reported in the literature, a high‐performance liquid chromatography (HPLC) assay that simultaneously quantifies these compounds has not yet been developed. This study aims to establish and validate an efficient HPLC analytical method using a photodiode array (PDA) detector for the simultaneous quantification of the four TKIs.MethodsCalibration standards were prepared by serial dilution of serum samples containing the four TKIs, followed by solid‐phase extraction. The four TKIs were eluted in order within 10 min using a binary HPLC gradient system.ResultsThe calibration ranges were 2–500 ng/ml for dasatinib, 100–5000 ng/ml for nilotinib, and 10–500 ng/ml for bosutinib and ponatinib. Intra‐day and inter‐day precision and accuracy values were found to be in accordance with the U.S. Food and Drug Administration guidelines. The recovery rates were 92.9%–96.0%, 80.7%–86.1%, 91.6%–99.0%, and 86.4%–92.6% for dasatinib, nilotinib, bosutinib, and ponatinib, respectively.ConclusionTo the best of our knowledge, this is the first report of an HPLC‐PDA analytical method that allows efficient simultaneous quantification of the four TKIs in the serum of patients with CML. We believe that the method developed herein can improve the efficiency of therapeutic drug monitoring in patients with CML in clinical practice.

A NOVEL VALIDATED STABILITY INDICATING ANALYTICAL METHOD FOR QUANTIFICATION OF EMPAGLIFLOZIN IN BULK AND MARKETED FORMULATION BY RP-HPLC APPLYING EXPERIMENTAL DESIGN APPROACH

A stability indicating reversed-phase high-performance liquid-chromatographic method for analysis of empagliflozin was developed and validated as per the ICH guidelines. Statistical design of experiment was applied for optimization, where independent variables used were methanol proportions in mobile phase and flow rate. Experiment was carried out on an analytical reversed phase column Cosmosil C18 (250 × 4.6 mm, 5 µm). Based on the results obtained from these studies, suitable mobile phase with appropriate composition was selected and utilized for method development applying DoE approach. The mobile phase used was methanol: water (85:15 V/V). The flow rate was set at 0.8 mL min-1 and UV detection was carried out at 225 nm. The retention time of empagliflozin was found to be 4.259 min. The lower solvent consumption along with the short analytical run time (≤05 minute) provides a cost effective and environment friendly chromatographic procedure. The measured signal was shown to be precise, accurate and linear over the concentration range tested (10-50 µg mL-1) with a correlation coefficient of 0.9999. Thus, the proposed methodology is rapid, selective and requires simple sample preparation steps and represents a good procedure for analysis of empagliflozin. Central Composite Design (CCD) was used for method development of empagliflozin. Two factors were selected with eight center points and response of empagliflozin was measured in terms of retention time which dependent on two factors namely, methanol content in mobile phase and flow rate. CCD was effective means in optimization of HPLC for analysis of empagliflozin in pharmaceutical formulation. The stability of the drug was examined over different stress conditions as per International Conference on Harmonization (ICH) guidelines. Results obtained from the force degradation studies indicated that the developed method is appropriate for stability studies.

Development and Validation of Analytical RP HPLC Method for Benidipine Hydrochloride

The aim of the present study is development and validation of analytical reverse phase (RP) high performance liquid chromatography (HPLC) from Benidipine Hydrochloride. HPLC method is used for quantification, identification and purification of particular analyte or compound. The developed HPLC chromatographic technique was validated based on international conference on harmonization (ICH) Q2 guidelines for accuracy, precision, linearity, range and robustness. High performance liquid chromatography technique is rapid and precise technique. Advance for the validated of Benidipine Hydrochloride in pure and tablet dosage form. Diethyl ether was extracted from plasma in the presence of 5M NaOH (Sodium Hydroxide) Diethyl ether is used as internal standard like Benidipine and Benidipine d5. Benidipine is dihydropyridine calcium channel blocker, which is used in the treatment of hypertension and angina pectoris and is used to examine the efficacy and safety of therapy with Benidipine in elderly hypertensive patients.

Development and Validation of Analytical Methods for Radiochemical Purity of 177Lu-PSMA-1.

Prostate Specific Membrane Antigen (PSMA) is a highly relevant target in nuclear medicine due to its overexpression in prostate cancer. The 68Ga/177Lu-PSMA-1 combination is a theranostic agent for the detection and treatment of tumors overexpressing the PSMA target. Specifically, 177Lu-PSMA-1 is used in the treatment of castration-resistant prostate cancer that is ineffective or intolerant to the latest generation of chemotherapy and/or hormone therapy. This radiopharmaceutical is manufactured in a radiopharmaceutical synthesizing unit and must pass a quality control where the radiochemical purity (RCP) is assessed prior to release of the batch. RCP evaluation is performed by high-performance liquid chromatography (HPLC) and thin-layer chromatography (TLC). Since there is no monograph for 177Lu-PSMA-1 in the European Pharmacopoeia, we validate the analytical methods according to the EANM recommendations adapted from ICH Q2. Specificity, linearity, accuracy, precision, intermediate precision, limit of quantification (LOQ) and robustness were described for HPLC and TLC in this study. The results obtained demonstrated the robustness and reliability of the HPLC and TLC analytical methods for the evaluation of the RCP of 177Lu-PSMA-1.

Stability of extemporaneously prepared sitagliptin phosphate solution.

Sitagliptin is a dipeptidyl peptidase-4 (DPP-4) inhibitor that is used orally in conjunction with diet and exercise to control sugar levels in type 2 Diabetes Mellitus patients. This study aimed to extemporaneously prepare SiP solution (1% w/v) using pure Sitagliptin phosphate (SiP) powder and assess its stability according to pharmaceutical regulatory guidelines. Four SiP solutions, coded T1, T2, T3, and T4, were extemporaneously prepared using pure SiP powder as a source of API. The most suitable one, in terms of general organoleptic properties, was selected for further investigations, including stability studies. For this last purpose, samples of the T4 solution were kept under two storage conditions, room temperature (25˚C and 60% Relative Humidity) and accelerated stability conditions (40˚C and 75% Relative Humidity). Assay, pH, organoleptic properties, related substances, and microbial contamination were evaluated for 4 consecutive weeks. A High-Performance Liquid Chromatography (HPLC) analytical method was developed and validated to be used for the analysis and quantification of SiP in selected solution formulation. The adopted formula had a pH on the average of 3 to 4. During the stability tests, all pH values remained constant. Furthermore, after 4 weeks of storage under both conditions, the SiP concentration was close to 100%. A stable SiP extemporaneous solution was successfully prepared using pure SiP powder. Patients with swallowing problems who use feeding tubes and are unable to take oral solid dosage forms may benefit from this research. Community pharmacists can prepare the solution using sitagliptin powder as the source of the active ingredient.

Development and Validation of an HPLC Analytical Method to Determine 6-Merpactopurine Concentration in Oral Suspension

Background: The 6-mercaptopurine is an active ingredient used to treat certain types of leukemia. This drug is an immunosuppressive and antineoplastic agent that belongs to the thiopurine class. In Brazil, 6-MP is currently available only in the form of 50 mg tablets, sold as Purinethol® and manufactured by Glaxo Smith Kline. The lack of the liquid formulation’s production impedes treatment, assuming that one of its advantages is through its applicability in pediatric patients, who show the highest incidence among others. Objective: The purpose of this work was to evaluate the development and application of a reversed phase high performance liquid chromatography (HPLC) method using an Agilent 1220 Infinity® G4294B chromatograph with photodiode array detector. Methods: HPLC assays were performed on an Eclipse plus® C18 column (4.6 x 150 mm, 3.5 μm particle size) using a gradient mode mixture of acetonitrile and aqueous acetic acid solution as a mobile phase, with a flow of 1 mL.min-1 and detection at 324 nm. The method was validated by determining its selectivity, linearity, precision, accuracy, and robustness. Results: Retention time for 6-mercaptopurine was 5.12 minutes. The detector’s response was linear at concentrations from 1.6 to 2.4 μg/mL. The results of the method’s accuracy evaluation showed mean recovery of the amount of substance added to the samples of between 99.88 and 100.5%. For precision, repeatability and intermediate precision were evaluated. The repeatability showed a standard deviation of 0.0737. The intermediate precision was assessed on three different. For three days of the studies, the values of the standard deviations were less than 3%, showing repeatability and intermediate precision adequate for the analytical method in question. The limit of detection was determined as 3.6 ng/mL. The limit of quantification was determined as 12 ng/mL. The chromatographic method was robust. Conclusion: The proposed method can be applied to control the quality of 6-MP oral suspension to ensure that the required content is delivered to pediatric oncology patients.

Ultrasonic-Assisted Thymol and Carvacrol Extraction from Za’atar Leaves Using Cold-Pressed Sesame Oil

Thymol and carvacrol found in Origanum syriacum “Za’atar” plant leaves have triggered interest among researchers for their natural antimicrobial and antifungal properties. However, their applications in modern pharmaceutical and cosmetic industries as natural preservatives remain challenging. In this research, extraction of thymol and carvacrol from Za’atar leaves has been investigated using the ultrasonic-assisted method and the use of sesame oil as the primary extraction solvent compared with other vegetable oils including sunflower and olive oils. In addition, a high-performance liquid chromatography (HPLC) analytical method was developed by using a C8 column and 0.05% trifluoroacetic acid as a buffering agent. The method was validated for specificity, linearity, repeatability, accuracy, and robustness for the analysis of the content of the two terpenes thymol and carvacrol in different Za’atar extracts. Using the validated analytical method, thymol and carvacrol content results revealed the best vegetable oil for extraction. Results showed that sesame oil had the highest content of thymol and carvacrol, followed by sunflower oil, and the least amount obtained by using olive oil. A consistent extraction result opens an opportunity for application in the pharmaceutical and cosmetic industries. For this reason, the essential extraction key parameters that influence the final content of thymol and carvacrol were evaluated. The highest impact originated from the quality and volume of sesame oil. Cold-pressed sesame oil resulted in a 23% higher content of thymol and decreased amount of carvacrol. It was found that wetting the Za’atar leaves powder with sesame oil was enough for extraction; any additional sesame oil volume dilutes the extracted sample. The second impact was the Za’atar cultivation conditions; less than 10% difference of thymol and carvacrol content was observed within Za’atar of Hebron origin. Finally, the origin of sesame seeds used for sesame oil production had the least impact.

Development and Validation of an HPLC Method for Analysis of Topotecan in Human Cerebrospinal Fluid and Its Application in Elimination Evaluation of Topotecan after Intraventricular Injection.

Simple SummaryIntrathecal administration of anticancer drugs is an effective strategy to treat meningeal leukemia and lymphoma. Topotecan is an anticancer drug, and its anticancer effect is expected via intrathecal administration. In this study, we developed a method to measure the concentration of topotecan in the cerebrospinal fluid (CSF) for clinical monitoring of personalized medicine. By controlling the unique structural feature of topotecan, a pH-dependent lactone ring-opening/closing reversible reaction, we established a simple high-performance liquid chromatography (HPLC) method to measure the total topotecan concentration in the CSF and confirmed that this method can be applied to clinical samples. In the present situation, wherein the concentrations were monitored, the disappearance of topotecan in the CSF was delayed, and signs of adverse effects were confirmed when a high concentration of topotecan was observed.Intrathecal administration of anticancer drugs is an effective dosage strategy, but the elimination of intraventricular drugs is not uniform in all patients. For safety, a system to evaluate local pharmacokinetics in the ventricles after administration is desired. In this study, we developed a simple and reproducible method to measure topotecan concentration in the cerebrospinal fluid (CSF) and confirmed its clinical applicability. High-performance liquid chromatography (HPLC) analysis was performed using a C18 column to measure the total topotecan concentration in the CSF. Clinical CSF samples were obtained from a 1-year old child with poor CSF absorption and stagnation. The patient received topotecan via an intraventricular subcutaneous reservoir. The HPLC method complied with the validation criteria. The lower limit of quantitation of this method was 0.04 µM. Using the developed method, we could determine the difference in topotecan CSF concentrations at 24 and 48 h after administration. The patient’s topotecan elimination rate was extremely low, and signs of adverse effects were observed at high CSF concentration of topotecan. The developed method could detect the delay in topotecan elimination after intrathecal injection. The findings of this study are valuable for the development of personalized treatments for the intrathecal administration of anticancer drugs.

A Review on Different Analytical Techniques for Determination of DNP Drugs and their Metabolites in Pharmaceutical Formulations

Background: Neuropathy is the most common perplexity of diabetes type 1 and 2. About 50% of diabetic patients develop diabetic neuropathic pain (DNP). At the beginning of diabetic neuropathy, there is a loss of sense, especially in the lower limb, accompanied by pain, and difficulty in movement. Glucose regulation effectively prevents the development of diabetic neuropathy in type 1 diabetic patients, but the consequences in type 2 diabetic patients are more drastic. Introduction: No single treatment exists to prevent or renovate the pain caused by diabetic neuropathy. The drugs used for the treatment of DNP come in various formulations and with different storage conditions. To date, a number of analytical methodologies have been reported for the analysis of DNP drugs. Few reports are published describing analytical methods of single DNP drugs. Methods: The main objective of this review is to compile the different analytical methods developed at UV-Vis (Ultraviolet-visible) spectrophotometer, HPLC (High Performance Liquid Chromatography), and LC-MS (Liquid Chromatography-Mass spectrometry) to identify and quantify the drug content in various formulations, which are used to treat or prevent the diabetic neuropathic pain mainly focusing on γ-aminobutyric acid analogues, anti-depressants, Serotonin Noradrenaline Reuptake Inhibitors (SNRIs), aldose reductase inhibitors, opioids, and dietary supplements. Results and Discussion: We have compiled UV-Vis, HPLC, and Liquid Chromatography-Mass spectrometry analytical methods developed to study the pharmacokinetic profile, quantify drug content, and their metabolites in plasma as well as pharmaceutical formulations. Conclusion: The authors believe that the mentioned studies in the report will help audible readers to select a suitable method for analysis of these drugs and also help researchers to develop a more convenient, fast, and sensitive method for these.