Validation Of Liquid Chromatographic Method Research Articles

A validated liquid chromatographic method for simultaneous quantification of Lidocaine hydrochloride and Diltiazem hydrochloride

A validated liquid chromatographic method for simultaneous quantification of Lidocaine hydrochloride and Diltiazem hydrochloride

Development and Validation of Liquid Chromatographic Method for Fast Determination of Lincomycin, Polymyxin and Vancomycin in Preservation Solution for Transplants.

In this study, a liquid chromatographic method was developed for the fast determination of lincomycin, polymyxin and vancomycin in a preservation solution for transplants. A Kinetex EVO C18 (150 × 4.6 mm, 2.6 µm) column was utilized at 45 °C. Gradient elution was applied using a mixture of mobile phases A and B, both including 30 mM phosphate buffer at pH 2.0 and acetonitrile, at a ratio of 95:5 (v/v) for A and 50:50 (v/v) for B. A flow rate of 1.0 mL/min, an injection volume of 20 µL and UV detection at 210 nm were used. A degradation study treating the three antibiotics with 0.5 M hydrochloric acid, 0.5 M sodium hydroxide and 3% H2O2 indicated that the developed method was selective toward lincomycin, polymyxin, vancomycin and their degradation products. Other ingredients of the preservation solution, like those from the cell culture medium, did not interfere. The method was validated with good sensitivity, linearity, precision and accuracy. Furthermore, lincomycin, polymyxin and vancomycin were found to be stable in this preservation solution for 4 weeks when stored at -20 °C.

Optimization of a Validated Liquid Chromatographic Method with Chemometric Approach for Estimation of Eugenol from Seed Powder Extract and Perform Anti-oxidant Activity

Background:: Developed and validated a new reverse phase high-performance liquid chromatographic (RP-HPLC) method, and it is prompt, precise, sensitive and robust for the esti-mation of eugenol in seed powder extract of Myristica fragrans. Objective:: The chemometric approach was utilized to obtain a rugged and definitive chromato-graphic method for the purpose. Methods:: Method variables such as acetonitrile (%) and flow rate were investigated for robust-ness and optimization by using a face-centered cubic design (FCCD). The Design Expert 12.0.1.0 software has been employed for this optimization. Further, the effects of factors were monitored on the concentrations of eugenol recovered from seed powder extract. Chromatograms have been developed by using an optimized mobile phase mixture containing methanol-water-acetonitrile (10:40:50, v/v/v) and Symmetry® C18 column (5 μm, 3.9 ×150 mm). The mobile phase was de-rived at a flow rate of 1 mL/min, and estimation of eugenol was performed at ʎmax 272 nm. Results:: Validation of the method has been carried out to reveal its selectivity, linearity, preci-sion, accuracy, LOD, and LOQ. Linear calibration plot for eugenol was held over the concentra-tion across 6.25 and 100 μg/mL (R2 = 0.999). The coefficient of variation was less than 1%, and accurate recovery of eugenol was observed between 96.80 and 99.56 %. The LOD and LOQ have been established to be 1.97 and 6.25 μg/mL, respectively. Intraday and Inter-day coefficients of variation have 1.81-1.91 and 1.92-1.57, respectively. Antioxidant activity (AA) by DPPH assay of seed powder extract in five different solvents was performed, and % AA activity was calculat-ed against ascorbic acid. Conclusion:: The validated method has been found to be highly robust and will be applied for the analysis of eugenol in formulation. The highest % AA has been reported in hexane solvent.

Quantitation of certolizumab pegol by validated liquid chromatography methods

Quantitation of certolizumab pegol by validated liquid chromatography methods

A Validated Liquid Chromatographic Method for the Estimation of Imatinib Mesylate in Dosage Forms: Application to Chemometrics based Robustness Testing and Greenness Assessment

An eco-friendly liquid chromatography method was developed for determining imatinib mesylate in pharmaceuticals. During pre-development studies, Using a greener mobile phase and a combination of qualitative and semi-quantitative green metrics techniques, the environmental sustainability of the procedure was maintained. Methanol:water (pH maintained at 3.5 using orthophosphoric acid) at 75:25%, v/v flowing at 1 mL/min was the final mobile phase used on a C-18 column. The diode array detector detected imatinib at 262 nm. Method specificity, accuracy, precision, selectivity and system suitability were tested over a linear concentration range of 5-120 μg/mL of imatinib. The limit of detection and limit of quantitation values were 1.5 and 5.0 μg/mL, respectively. In addition, the factorial design showed the procedure to be reliable with minimum testing. Finally, the method recovered the maximum (> 99%) of the analyte from the dosage form. Overall, the present method is suitable for routine applications in quality control of dosage forms of imatinib.

Diffusion of amoxicillin into heart valves from infective endocarditis patients.

Amoxicillin is the drug of choice in the management of streptococcal and enterococcal infective endocarditis (IE) but little is known regarding amoxicillin diffusion into infected heart valves. Herein, we assessed amoxicillin valvular distribution and related pharmacokinetic/pharmacodynamic (PK/PD) target attainment in IE patients undergoing heart valve surgery. In this 2-year prospective study, patients with IE treated by continuous infusion of amoxicillin and undergoing a surgical valve replacement were included. Both amoxicillin plasma and tissue concentrations were measured the day of surgery. Amoxicillin concentration in plasma and crushed heart valves were measured by a validated liquid chromatography method coupled with ultra-violet and tandem mass spectrometry, respectively. MIC and MBC of amoxicillin were determined for all available isolates. The rate of achievement of PK/PD efficacy parameters were assessed. Twenty-two heart valves were removed from 20 patients. Bacterial aetiology was streptococcal (n = 17) and enterococcal (n = 3). Amoxicillin mean daily dose was 12 ± 3 g/24 h, mean plasma concentration was 29 ± 21 mg/L (n = 15), mean tissue concentration was 23 ± 15 mg/L (n = 22). Median diffusion rate was 62%. Patients reached a plasma concentration target >4XCMI (n = 13). Tissue concentrations were bactericidal for all streptococcal IE but not for enterococcal IE. Amoxicillin intravalvular measurements in IE treated patients showed significant penetration into the infectious site. These data are reassuring that in situ bactericidal concentrations can be largely achieved in the management of streptococcal IE and support the need for combination antibiotic therapy for enterococcal IE.

Synthesis and standardization of an impurity of acetaminophen, development and validation of liquid chromatographic method

One of the impurities of acetaminophen, N,N'-(oxydi-4,1-phenylene)diacetamide (ODAA), which is not specified in the organic impurities analysis method of acetaminophen by high performance liquid chromatography (HPLC) in American Pharmacopoeia Version 42 (USP 42), was synthesized, characterized and standardized. A new and optimized liquid chromatographic method for the determination of organic impurities of acetaminophen was developed using an ultra-high performance liquid chromatographic (UHPLC) system, which can separate this impurity. This new liquid chromatographic method has been optimized and validated for the simultaneous determination of acetaminophen related compound B, acetaminophen related compound C, acetaminophen related compound D, acetaminophen related compound J and ODAA, the organic impurities in acetaminophen drug substance. Acetaminophen was also subjected to stress-testing under acidic hydrolysis, alkaline hydrolysis, oxidative degradation, thermal degradation and photolytic degradation for 15 days. The impurity molecule, ODAA was synthesized using 4,4′-oxydianiline and acetic anhydride. The chemical structure of the synthesized ODAA molecule was confirmed by characterization studies. The potency of ODAA was found to be 99.64% as a result of the relevant analyses. The chromatographic separation was achieved on a C8 (150 mm × 2.1 mm; 2-µm particle size) reversed-phase column using a gradient elution, being solvent A: methanol-water-glacial acetic acid (50:950:1, v/v/v) and solvent B: methanol-water-glacial acetic acid (500:500:1, v/v/v) flowing at a rate of 0.2 mL/min. The limits of quantitation (S/N 10:1) were 1.248 µg/mL for acetaminophen, 0.373 µg/mL for acetaminophen related compound B, 1.217 µg/mL for acetaminophen related compound C, 0.369 µg/mL for acetaminophen related compound D, 0.125 µg/mL for acetaminophen related compound J and 0.373 µg/mL for ODAA. The individual mean recoveries of each impurity molecule spiked into acetaminophen samples at different concentration levels ranged from 93% to 104%. The method developed for UHPLC instrument was successfully applied to the analyses of different lots of acetaminophen. Thus, the proposed method can be used for determination of this impurity in the presence of other specified impurities of acetaminophen.

Influence of Gender, Body Mass Index, and Age on the Pharmacokinetics of Itraconazole in Healthy Subjects: Non-Compartmental Versus Compartmental Analysis.

Itraconazole is a triazole antifungal agent with highly variable pharmacokinetics, with not yet fully identified factors as the source of this variability. Our study aimed to examine the influence of body mass index, gender, and age on the first dose pharmacokinetics of itraconazole in healthy subjects, using pharmacokinetic modeling, non-compartmental versus compartmental ones. A total of 114 itraconazole and hydroxy-itraconazole sets of plasma concentrations of healthy subjects of both genders, determined using a validated liquid chromatographic method with mass spectrometric detection (LC-MS), were obtained for pharmacokinetic analyses performed by the computer program Kinetica 5®. Genetic polymorphism in CYP3A4, CYP3A5, CYP1A1, CYP2C9, and CYP2C19 was analyzed using PCR-based methods. Multiple linear regression analysis indicated that gender had a significant effect on AUC as the most important pharmacokinetics endpoint, whereas body mass index and age did not show such an influence. Therefore, further analysis considered gender and indicated that both geometric mean values of itraconazole and hydroxy-itraconazole plasma concentrations in men were prominently higher than those in women. A significant reduction of the geometric mean values of Cmax and AUC and increment of Vd in females compared with males were obtained. Analyzed genotypes and gender differences in drug pharmacokinetics could not be related. Non-compartmental and one-compartmental models complemented each other, whereas the application of the two-compartmental model showed a significant correlation with the analysis of one compartment. They indicated a significant influence of gender on itraconazole pharmacokinetics after administration of the single oral dose of the drug, given under fed conditions. Women were less exposed to itraconazole and hydroxy-itraconazole than men due to poorer absorption of itraconazole, its more intense pre-systemic metabolism, and higher distribution of both drug and its metabolite.

Dissipation kinetics and the pre-harvest residue of chlorantraniliprole in pigeon pea Cajanus cajan L. succulent pods Using Ultra-High-Performance Liquid Chromatography with Photodiode array detector (UHPLC-PDA)

Studies were conducted to evaluate insecticide residues of Chlorantraniliprole in pigeon pea succulent pods after foliar application. Chlorantraniliprole was sprayed at 0.6ml/l on pigeon pea crop at the pod formation stage to control pod borers like Helicoverpa armigera and Maruca vitrata. Samples were drawn at 0, 1, 5, 10, 15, 20, 25, and 30 days after spray. A validated liquid chromatography method with a Photodiode Array (PDA) detector was used for the residue analysis of chlorantraniliprole. Separation was achieved through the C18 column in the reverse phase. The calibration graphs of chlorantraniliprole in acetonitrile solvent or five blank matrices were linear within the tested interval of 0.1 to 1ppm with a coefficient of determination over 0.9990. Dissipation of chlorantraniliprole was studied in first-order kinetic models (for which the coefficient of determination, R2 was 0.8684). Residues of chlorantraniliprole was 3.57, 3.16, 1.61, 1.13, 0.49, 0.21, 0.05 and 0.00mg/kg at 0, 1, 5, 10, 15, 20, 25 and 30 days after spraying. The residue level reached below the tolerance limit (MRL) (2mg/kg BW) of Codex Alimentarius Commission (CAC) on Pesticide Residues after 5 days of spray and below the detectable level after 25 days of spray in succulent pods and recorded a biological half-life of 4.36 days.

Development and validation of liquid chromatography method for determination of Ibrutinib in finished dosage forms using quality by design approach

AbstractA simple, precise, linear, robust, accurate, and stability‐indicating liquid chromatography method was developed and validated to determine Ibrutinib in finished solid dosage forms by reversed‐phase high‐performance liquid chromatography/photodiode array detector. Separation was achieved using a Luna C18 150 mm × 4.6 mm × 3.0 μm with a suitable mobile phase. The mobile phase: A consists of a 10 mM phosphate buffer concentration and 1 mL triethylamine, adjusted to pH 5.6 with a diluted orthophosphoric acid solution and acetonitrile in the ratio of 95:5 v/v to enhance the results. Moreover, mobile phase ‐ B contains 85% of acetonitrile. The optimized chromatographic conditions such as flow rate 1.0 mL/min, injection volume 10 μL, column temperature 40°C, and wavelength 258 nm. The proposed method is significant because it was developed by the Quality by Design approach. All impurities were identified, such as degradation and placebo impurities without interference at principle peak retention time. After development, it has been validated as per current regulatory guidelines. Obtained recovery between 98 and 102% at 50–200% level; linearity found (r2) = 0.9999 from 20 to 200% level; precision results achieved <2.0% relative standard deviation; and the robustness study results are found satisfactory. It's beneficial.

Development and validation of liquid chromatography method for simultaneous determination of multiclass seven antibiotic residues in chicken tissues

BackgroundAntibiotics are routinely used on poultry for therapy and prevention of diseases and to enhance animal growth. The objective of this study was to develop and validate a sensitive and reliable liquid chromatography with UV detection (LC-UV) method for the simultaneous determination of seven multiclass antibiotic residues (amoxicillin, ampicillin, penicillin, sulfamethoxazole, gentamicin, ciprofloxacin, and erythromycin) in chicken tissues.MethodsThe liquid chromatography method with UV detection was optimized for complete separation of the seven selected antibiotic compounds with reversed phase and isocratic elution using Hypersil BDS-C18 (3 µm, 100 mm × 4 mm) column. The mobile phase consisted a ratio of 0.05 M Na2HPO4, acetonitrile and methanol (70:10:20), at UV absorption wavelength of 230 nm. The column thermostat was set at 40 °C, the mobile phase flow rate was 1 mL min−1, and the injection volume was 20 μL.ResultsAll the seven standard compounds were eluted within 14 min. The results for: linearity, precision, sensitivity, accuracy, specificity, decision limit (CCα), detection capability (CCβ), suitability and method robustness were validated according to the criteria of Commission Decision 2002/657/EC guidelines. Calibration plot correlation coefficients ranged from 0.9983 to 0.9998 and the percent relative standard deviations for repeated analysis were below 5% indicating acceptable method precision. The limits of detection (LODs) and quantification (LOQs) ranged from 0.098–0.255 μg kg−1 to 0.297–0.574 μg kg−1, respectively. The accuracy study yielded recoveries in the ranges 98.1–107% for the pure compounds and 94.0–102% for the spiked drug free chicken tissue samples.ConclusionsThe method was found to be appropriate for simultaneous determination of five different classes of seven antibiotic residues in chicken tissues. Furthermore, this is the first instance for the simultaneous determination of seven multiclass, multi-residues analysis using LC-UV from chicken tissue samples. This is a cost-effective and alternative method with simple instrumentation approach for laboratories that lack highly specialized state-of-the-art instrumentation.

Development and Validation of Liquid Chromatography Method for Simultaneous Estimation of Miconazole and Clobetasol and Characterization of Hydrolytic Degradation Products using Liquid Chromatography with Tandem Mass Spectrometry

Development and Validation of Liquid Chromatography Method for Simultaneous Estimation of Miconazole and Clobetasol and Characterization of Hydrolytic Degradation Products using Liquid Chromatography with Tandem Mass Spectrometry

Development and validation of liquid chromatographic method for the determination nitrofuran residues in honey

Sensitive, accurate and efficient Liquid Chromatographic Method is developed for the quantitative determination of Nitrofuran residues in fish samples. It was found that the coefficient of variation for all four test substances of the Nitrofuran group is from 0.03 ìg / ml less than 2%, respectively the detection minimum was considered to be 0.03ìg / ml; 376 nm wavelength is specific for Nitrofurans; For the quantification of nitrofuran residues in a fish sample validation of the developed Liquid Chromatographic Method revealed complete compliance of the method (Guidance for Industry Bioanalytical Method Validation U.S. Department of Health and Human Services Food and Drug Administration Center for Drug Evaluation and Research (CDER) Center for Veterinary Medicine (CVM) May 2001) with the following validation characteristics of the requirements: detection minimum, specificity, accuracy, correctness and linearity.

Development and validation of liquid chromatographic method for the determination of nitrofuran residues in fish samples

Development and validation of liquid chromatographic method for the determination of nitrofuran residues in fish samples

Koncentracije itrakonazola i hidroksi-itrakonazola nakon oralne primene leka kod zdravih ljudi - uticaj pola

Introduction: Itraconazole is an antifungal drug belonging to the triazole group. After oral application, it is rapidly absorbed, but its bioavailability is reduced due to an intensive first-pass through the liver metabolism effect. A large number of metabolites (the most important of which is hydroxyitraconazole) are produced by isoform CYP3A4 of cytochrome P450. The variability of itraconazole pharmacokinetics is the result of numerous factors that have not yet been fully clarified. Our study aimed to investigate the influence of gender on itraconazole and hydroxyitraconazole plasma concentrations in healthy adults after an oral application of a single dose of itraconazole. Methods: Pharmacokinetic analysis was performed after oral administration of itraconazole in a single dose of 100 mg to 22 male and 16 female healthy volunteers. Blood samples were collected before taking the drug and at appropriate time intervals up to 72 hours later. Itraconazole and hydroxyitraconazole concentrations were determined using a validated liquid chromatography method with mass spectrometric detection (LC-MS/MS) and their pharmacokinetic parameters were calculated by using the Kinetica programme, version 5.0: Cmax, Tmax, PIK (0-72), PIK (0-∞), T1/2, and Ke. Results: The median values of both itraconazole and hydroxyitraconazole were lower in women in comparison to men during the whole period of observation. Moreover, median values of Cmax, PIK(0-72) and PIK(0-∞) parameters were also significantly lower in women, concerning both itraconazole (p=0.005, 0.036 and 0.036, respectively) and its metabolite (p=0.004, 0.010 and 0.044, respectively). Elimination parameters - T1/2 and Ke did not differ between genders. Conclusion: Women were less exposed to itraconazole and its active metabolite than men following an oral application of the drug, possibly as a result of lower bioavailability due to a more intense pre-systemic metabolism, as a result of a higher expression and/or activity of the isoform enzyme, which metabolises itraconazole, and which would need to be confirmed by pharmacogenomic analysis.

Microextraction and Chromatographic Analysis of Budesonide Epimers in Exhaled Breath Condensate

Background: Analysis of drug concentrations in biological fluids is required in clinical sciences for various purposes. Among other biological samples, exhaled breath condensate (EBC) is a potential sample for follow up of drug concentrations. Methods: A dispersive liquid-liquid microextraction (DLLME) procedure followed by a validated liquid chromatography method was employed for the determination of budesonide (BDS) in EBC samples collected using a homemade setup. EBC is a non-invasive biological sample with possible applications for monitoring drug concentrations. The proposed analytical method is validated according to the FDA guidelines using EBC-spiked samples. Its applicability is tested on EBC samples collected from healthy volunteers receiving a single puff of BDS. Results: The best DLLME conditions involved the use of methanol (1 mL) as a disperser solvent, chloroform (200 μL) as an extraction solvent, and centrifugation rate of 3500 rpm for 5 minutes. The method was validated over a concentration range of 21-210 μg·L-1 in EBC. Inter- and intra-day precisions were less than 10% where the acceptable levels are less than 20%. The validated method was successfully applied for the determination of BDS in EBC samples. Conclusion: The findings of this study indicate that the developed method can be used for the extraction and quantification of BDS in EBC samples using a low cost method.

A Validated Liquid Chromatographic Method for Berberine Analysis in Tissue and Application.

Simple and rapid high-performance liquid chromatography methods were developed for the determination of berberine (BB) in various rat tissues so as to evaluate a P-gp inhibitor, glycyrrhetinic acid (GA), on BB's oral bioavailability. Acetonitrile was used to extract BB from tissues and showed different extraction recoveries in diverse tissues. The intra- and interday precision and accuracy were less than 10%. Long-term stability, pre (post) -preparative stability, and freeze-thaw stability were evaluated, and the results showed it could meet the need of this study. The proposed methods were subsequently applied to investigate the possible drug-drug interaction of GA and BB in vivo from the aspect of tissue distribution. The results showed that no significant difference was found between the group of low dose and high dose at the same time point. The tissue distributions show a saturated model, i.e., the content of BB in tissue tends to be constant while its dose is more than 200 mg/kg. Besides, the contents of BB ranged from high to low according to the order of the liver, kidney, and spleen. The BB content in the liver is especially high as compared to other tissues.

Chemometrics supported optimization of a multi-attribute monitoring liquid chromatographic method for estimation of palbociclib in its dosage form: Application to a new regulatory paradigm

The objective of present work was to develop a validated liquid chromatographic method for the estimation of palbociclib in its solid dosage forms by employing a new systematic concept. Risk assessment and control measures were undertaken along with chemometrics assistance to establish the robust method performance for studied analytical attributes viz. analyte retention, resolution, plate number, and tailing factor. Methanol %, flow rate, and pH were found influential on the performance of studied analytical attributes and optimized using a Box-Behnken experimental design. Monte-Carlo simulation was performed to evaluate the performance of the analytical procedure. A multi-attribute monitoring liquid chromatographic method employing methanol: 0.01M KH2PO4 buffer of pH 3.5 (70:30, v/v) was used with a reversed-phase column. Flow rate at 1.2mL/min and detection at 265nm monitored peak responses. The method efficiently separated analyte from the internal standard caffeine (resolution>16). Specificity (resolution>2.0), linearity (2-64μg/mL), accuracy (>99%) and precision (%RSD<1%) were well in accord with regulatory requirements. Further, analyte was detected at 1μg/mL and was stable over applied stress conditions. In a nutshell, the novel approach produced an accurate method for estimation of palbociclib in tablets with optimum method performance.

Bioequivalence of Two Oral Ciprofloxacin Extended-Release Formulations in Healthy Mexican Volunteers

Introduction. Oral ciprofloxacin extended-release formulation decreases the risk of treatment failure and prevents the development of antimicrobial resistance. However, non-equivalent formulations lead to subtherapeutic plasma drug concentrations, increasing the risk of such problems. Objective. To determine the bioequivalence of two oral ciprofloxacin extended-release tablet formulations (1,000 mg) in healthy Mexican volunteers. Material and Methods. In this open-label 2 × 2 crossover design study, 26 healthy volunteers were randomly allocated to receive a single dose of the reference drug Cipro XR® (Bayer, Mexico) and the test formulation Ciproflox DM® (Senosiain Laboratories, Mexico). Blood samples were obtained for 24 hours. Ciprofloxacin plasma levels were quantified using a validated liquid chromatography method. Pharmacokinetic parameters were obtained by standard non-compartmental analysis. In order to determine bioequivalence, log-transformed test/reference ratios of Cmax, AUC0-t, and AUC0-inf were compared by an analysis of variance, followed by the 90 % confidence intervals and the Schuirmann bilateral test. Results. The 90 % confidence intervals ranged from 85.69 to 114.31 % for Cmax, 85.16-115.84 % in AUC0-t, and 85.39-114.61 % for AUC0-inf, all cases were within bioequivalence acceptance criteria (80-125 %). Schuirmann test verified the probability that the values were within these criteria (p &lt; 0.05). No side-effects were observed with any treatment. Conclusions. The results obtained demonstrate bioequivalence between the analyzed formulations.

Development and validation of liquid chromatographic methods for the estimation of the acceptance values of some hazardous preservatives in pharmaceutical formulations. A comparative study

Gradient and isocratic liquid chromatography were applied for the simultaneous determination of three preservatives, namely; benzyl alcohol (BA), methyl paraben (MP) and propyl paraben (PP). Separation for both elution modes was carried out using a C18 column kept at 60°C throughout the analysis, accompanied with a flow rate of 2 mL/min and UV detection at 254 nm. Gradient liquid chromatography used a time programme with two solvents (0.1% formic acid and acetonitril), while isocratic elution was performed with 0.1% formic acid: 2-propanol in a ratio of 70:30, v/v. Full validation study was conducted for both separation modes, where both of them were linear over the concentration ranges of 100.0–2000.0, 2.5–100.0, and 2.0–200.0 µg/mL for BA, MP and PP respectively. Using gradient elution, the detection limits for BA, MP, and PP were found to be 50.0, 1.8, and 1.5 µg/mL respectively. The corresponding values in isocratic elution were 60.0, 1.5, and 1.3 µg/mL. On the other hand, the limit of quantification for BA, MP, and PP using gradient mode are 70.0, 2.0, and 1.8 µg/mL respectively. While isocratic elution resulted in corresponding values of: 80.0, 2.3, and 1.7 µg/mL. The accuracy of the proposed method was illustrated from the high percentage recoveries values which were 99.67%, 100.42%, and 99.85% for BA, MP, and PP respectively using gradient mode, with corresponding values of 99.79%, 100.39%, and 99.87% for the isocratic elution mode. In addition, gradient elution was further applied to detect and assay the selected preservatives in different pharmaceutical formulations demonstrating that their quantities are within the stated ranges, and eventually, a comparative overview was introduced.