Development and validation of HPTLC and green HPLC methods for determination of furosemide, spironolactone and canrenone, in pure forms, tablets and spiked human plasma

The improvement of routine drug quality control analysis of some antihypertensive drugs using high-performance thin-layer chromatography densitometry method with greenness profile evaluation

The common antihypertensive drugs are B-blockers and diuretics. For the determination of beta-blocker medicines (bisoprolol fumarate and carvedilol) and diuretic drug (Furosemide), new and accurate chromatographic method has been developed. The separation was achieved using a developing system that includes chloroform:methanol:ethyl acetate:ammonia (6:2:2:0.2 by volume) as a mobile phase and the bands were detected at 240 nm. The concentration ranges were 5-25, 1-7, and 1-3.5 μg/band for bisoprolol fumarate, carvedilol, and furosemide, respectively. This chromatographic approach is the first methodology for simultaneously determining bisoprolol fumarate, carvedilol, and furosemide in their pure forms and in their pharmaceutical dosage forms. The advantages of using known analytical procedures are their simplicity, speed, cost effectiveness, lack of laboriousness, and ability to save time as the three tablets are determined in one step and can be used for routine analysis of the investigated combinations in quality control laboratories. According to International Conference of Harmonization guidelines, the established procedures have been validated, and the results were statistically compared to those obtained by the reported reversed-phase-high-performance liquid chromatography methods using Student's t-test and F-test, with no significant difference between them, indicating that the proposed methods can be used for routine drug quality control analysis.

Estimation of Two Diuretics Using Fluorescent Nitrogen Doped Carbon Quantum Dots: Application to Spiked Human Plasma and Tablets

Highly fluorescent nitrogen doped carbon quantum dots (N-CQDs) were prepared by a single-step method based on microwave heating of cane sugar and urea. The produced N-CQDs were applied as nano-sensors for the spectrofluorimetric determination of eplerenone and spironolactone. A strong emission band at 376 nm was obtained after excitation at 216 nm due to the produced N-CQDs. The native fluorescence of N-CQDs was obviously quenched upon adding increased concentrations of each drug. A strong correlation was found between the fluorescence quenching of N-CQDs and the concentration of each drug. The method was found to be linear over the range of 0.5 to 5.0 μg/mL for eplerenone and 0.5 to 6.0 μg/mL for spironolactone with LOQ of 0.383 μg/mL and 0.262 μg/mL. The developed method was further extended for determination of both drugs in their pharmaceutical tablets and spiked human plasma. The results obtained were statistically compared with those of reported methods. The mechanism of fluorescence quenching of N-CQDs by the two drugs was discussed.

Diuretics in Different Samples: Update on the Pretreatment and Analysis Techniques

Diuretics are drugs that promote the excretion of water and electrolytes in the body and produce diuretic effects. Clinically, they are often used in the treatment of edema caused by various reasons and hypertension. In sports, diuretics are banned by the World Anti-Doping Agency (WADA). Therefore, in order to monitor blood drug concentration, identify drug quality and maintain the fairness of sports competition, accurate, rapid, highly selective and sensitive detection methods are essential. This review provides a comprehensive summary of the pretreatment and detection of diuretics in various samples since 2015. Commonly used techniques to extract diuretics include liquid-liquid extraction, liquid-phase microextraction, solid-phase extraction, solid-phase microextraction, among others. Determination methods include methods based on liquid chromatography, fluorescent spectroscopy, electrochemical sensor method, capillary electrophoresis and so on. The advantages and disadvantages of various pretreatment and analytical techniques are elaborated. In addition, future development prospects of these techniques are discussed.

Use of green fluorescent nano-sensors for the determination of furosemide in biological samples and pharmaceutical preparations

BACKGROUND

Carbon quantum dots (CQDs) are new class of carbon nanoparticles. Recently, they have been widely used as fluorescent probes due to their easy accessibility, optical properties and chemical inertness. Many available precursors are used in the synthesis of carbon quantum dots. The electrical and optical properties of CQDs could be enhanced by doping hetero atoms such as nitrogen or sulfur into their structure.

OBJECTIVE

The current work presents the synthesis and characterization of water-soluble nitrogen doped carbon quantum dots (N-CQDs) and their use as fluorescent nano-sensors for the spectrofluorimetric determination of furosemide in its pharmaceutical preparations and spiked human plasma.

METHODS

A domestic microwave was used to prepare the N-CQDs by heating a solution of sucrose and urea till complete charring (about ten minutes). The produced N-CQDs exhibit a strong emission band at 376 nm after excitation at 216 nm. Furosemide caused a quantitative quenching in the fluorescence intensity of the produced N-CQDs.

RESULTS

The proposed method was validated according to ICH Guidelines. The method was found to be linear over the range of 0.1-1.0 µg/mL with LOQ of 0.087 µg/ml.

CONCLUSION

Ecofriendly nano fluorescent sensors (N-CQDs) were successfully synthesized. The size of N-CQDs was distributed in the range of 6.63 nm to 10.23 nm with an average of 8.2 nm. The produced N-CQDs were used as fluorescent probes for the estimation of furosemide in its pharmaceutical preparations as well as spiked human plasma samples.

Simultaneous determination of five diuretic drugs using quantitative analysis of multiple components by a single marker

BACKGROUND

Loop diuretics are commonly used in clinical practice to manage high fluid loads and to control fluid balance. In this paper, a novel quantitative analysis method for multiple components with a single marker (QAMS) was developed for the simultaneous determination of 5 diuretic drugs furosemide, torasemide, azosemide, etacrynic acid, and bumetanide, by HPLC. Qualitative analysis was performed using relative retention time and ultraviolet (UV) spectral similarity as the double indicator. The QAMS method was conducted with etacrynic acid as an internal reference substance. The quantities of the other four diuretics were calculated by using the relative correction factors for etacrynic acid. The quantities of the 5 diuretic drugs were also determined by the external standard method (ESM). Chromatographic separation was achieved on a Shimadzu HC-C₁₈ column (150 mm × 4.6 mm, 5 µm) using 50 mM potassium dihydrogen phosphate (pH adjusted to 4.0 with phosphoric acid) with acetonitrile (64:36, v/v) as the mobile phase at a flow rate of 1.0 mL/min and a column temperature of 30 ℃.

RESULTS

Under these conditions, the 5 diuretic drugs were well separated, showing linear relationships within certain ranges. The quantitative results showed that there was no significant difference between the QAMS and ESM methods.

CONCLUSIONS

Overall, the HPLC-QAMS analytical scheme established in this study is a simple, efficient, economical, and accurate method for the quantitative evaluation of 5 diuretic drugs.

Solvent bar microextraction combined with HPLC-DAD for simultaneous determination of diuretics in human urine and plasma samples

BACKGROUND

A simple and powerful microextraction procedure, the solvent bar microextraction (SBME), was used for the simultaneous determination of two diuretics, furosemide and spironolactone in human urine and plasma samples, using high-performance liquid chromatography coupled with diode array detection (HPLC-DAD).

METHODS

The appropriate amount (2 µL) of 1-octanol as an organic solvent confined within (2.5 cm) of a porous hollow fiber micro-tube, sealed at both ends was used for this procedure. The conditions for the SBME were optimized in water and the analytical performance were examined in spiked human urine and plasma samples.

RESULTS

The optimized method exhibited good linearity (R2 > 0.997) over the studied range of higher than 33 to 104 µg L-1 for furosemide and spironolactone in urine and plasma samples, illustrating a satisfactory precision level with RSD values between 2.1% and 9.1%.

DISCUSSION

The values of the limits of detection were found to be in the range of 6.39 to 9.67 µg L-1, and extraction recovery˃ 58.8% for both diuretics in urine and plasma samples. The applicability and effectiveness of the proposed method for the determination of furosemide and spironolactone in patient urine samples were tested.

CONCLUSION

In comparison with reference methods, the attained results demonstrated that SBME combined with HPLC-DAD was proved to be simple, inexpensive, and promising analytical technology for the simultaneous determination of furosemide and spironolactone in urine and plasma samples.

A Fast and Validated HPLC Method for Simultaneous Determination of Dopamine, Dobutamine, Phentolamine, Furosemide, and Aminophylline in Infusion Samples and Injection Formulations

A simple, fast, and validated HPLC method was developed for the simultaneous quantization of five cardiovascular agents: dopamine (DPM), dobutamine (DBM), phentolamine (PTM), furosemide (FSM), and aminophylline (APL) either in infusion samples or in an injection dosage form. The proposed method was achieved with a 150 mm × 4.6 mm, 5.0 μm C₁₈ column, by using a simple linear gradient. Mobile phase A was buffer (50 mM KH₂PO₄) and mobile Phase B was acetonitrile at a flow rate of 1.0 mL/min. The column temperature was kept at 30°C, and the injection volume was 20 μL. All analytes were separated simultaneously at a retention time (tr) of 3.93, 5.84, 7.06, 8.76, and 9.67 min for DPM, DBM, PTM, FSM, and APL, respectively, with a total run time of less than 15.0 min. The proposed method was validated according to ICH guidelines with respect to accuracy, precision, linearity, limit of detection, limit of quantitation, and robustness. Linearity was obtained over a concentration range of 12.0-240.0, 12.0-240.0, 20.0-200.0, 6.0-240.0, and 10.0-200.0 μg/mL DPM, DBM, PTM, FSM, and APL, respectively. Interday and intraday accuracy and precision data were recorded in the acceptable limits. The new method has successfully been applied for quantification of all five drugs in their injection dosage form, infusion samples, and for evaluation of the stability of investigated drugs in mixtures for endovenous use. The results of the stability study showed that mixtures of DPM, DBM, PTM, FSM, and APL in 5% glucose or 0.9% sodium chloride injection were stable for 48 hours when stored in polypropylene syringes at 25°C.

Green analysis of newly approved binary omeprazole/aspirin mixture in presence of aspirin impurity using ultra-high-performance liquid chromatography and thin-layer chromatography methods

Two green, simple, and accurate chromatographic methods were developed and validated for the simultaneous determination of omeprazole and aspirin mixture in the presence of salicylic acid, a major impurity of aspirin. Method A is a reversed-phase ultra-high-performance liquid chromatography; the separation was performed on a C18 column, with a mobile phase composed of ethanol:0.1% aqueous solution of triethylamine acidified with orthophosphoric acid (pH 3) (30:70, v/v) at 0.15 mL/min flow rate and 230 nm. Omeprazole, aspirin, and aspirin impurity retention times were 7.47, 4.40, and 5.13 min, respectively. Good linearity was achieved in the concentration ranges of 5-80, 5-85, and 3-50 μg/mL for the three mentioned components, respectively. Method B is thin-layer chromatography (TLC) where silica gel TLC F254 plates were utilized to achieve separation using ethanol:ethyl acetate (2:8, v/v) as a developing system at 240 nm. The resulted R_f values were 0.83, 0.65, and 0.23 for omeprazole, aspirin, and impurity, respectively. The concentration ranges of 0.1-3 μg/band for the three drugs showed good linearity. The proposed methods are eco-friendly and greener when compared to the already reported method (Microchemical Journal, 152, 104350). This is the first use of TLC method for the determination of the three drugs. International Council for Harmonization (ICH) guidelines were followed to ensure the validity of developed methods.

Development and Validation of Two Chromatographic Methods for Simultaneous Determination and Quantification of Amiloride Hydrochloride, Hydrochlorothiazide, and Their Related Substances, in Pure and Tablet Forms

Background

Amiloride hydrochloride (AM) is a potassium sparing diuretic, while hydrochlorothiazide (HCZ) is the protype of thiazide diuretics. The combining of the studied drugs exhibits a synergistic effect. Moreover, HCZ prevents the potassium depletion side effect caused by AM.

Objective

Two accurate and precise simultaneous chromatographic separation methods were promoted and investigated to quantify AM, HCZ, official impurities of HCZ (cholorothiazide and salamide), and the official impurities of AM (methyl 3, 5-diamino-6-chloropyrazine-2-carboxylate).

Methods

The components of the quintuple mixture were quantified by two methods. The first method was high-performance thin layer chromatography (HPTLC), where exemplary separation was achieved on silica gel HPTLC F254 plates at the stationary phase using ethyl acetate–ethanol–ammonia solution (8 + 2 + 0.2, v/v) as a developing system. Scanning of bands at 273 nm was done. The second method was a reversed-phase chromatography (RP-HPLC) method using C18 (4.6 × 100 mm) column and mobile phase comprising 0.1% phosphoric acid solution–acetonitrile (90 + 10, v/v) with UV determination at 273 nm. Adjustment of the flow rate at 1 mL/min and pH at 3.6 was performed.

Results

Regarding RP-HPLC, optimum separation of the quintuple mixture was achieved within just five minutes. According to HPTLC, symmetric and sharp peaks were separated on the resulted chromatogram. Validity of the introduced methods was investigated by applying international conference on harmonization (ICH) guidelines.

Conclusions

The methods were successfully applied for assays of the studied drugs in their pure and tablet forms. No significant difference was revealed through application of statistical comparison between results of the suggested methods and those of the reported method regarding both accuracy and precision.

Simultaneous determination of canrenone, digoxin and tolvaptan by UHPLC-MS/MS: application in heart failure patients

Aim: Heart failure patients are frequently given comedication of digoxin and diuretics like spironolactone and tolvaptan. A UHPLC-MS/MS assay for determining canrenone (main active metabolite of spironolactone), digoxin and tolvaptan simultaneously should be developed so as to support related drug-drug interaction studies. Results: A UHPLC-MS/MS method for simultaneous determination of these three drugs in human plasma was established and fully verified as per CFDA guidelines. Chromatographic separation was achieved using a 4-min isocratic elution. Mass analyses were performed under positive electrospray ionization mode. The calibration curves were established over 1.0-400.0 ng/ml for canrenone and tolvaptan while over 0.1-40.0 ng/ml for digoxin. Conclusion: The developed method was feasible in detecting concentration and related drug-drug interaction studies.