Simple and Accurate HPTLC-Densitometric Method for Quantification of Delafloxacin (A Novel Fluoroquinolone Antibiotic) in Plasma Samples: Application to Pharmacokinetic Study in Rats

Quantification of Suvorexant in Human Urine Using a Validated HPTLC Bioanalytical Method

Suvorexant (SUV) is a new sedative/hypnotic medicine that is recommended to treat insomnia. It is an important medicine from a forensic point of view due to its sedative/hypnotic and depressant effects. To the best of our knowledge, high-performance thin-layer chromatography (HPTLC) bioanalytical methods have not been published to measure SUV in human urine and pharmaceutical samples. Accordingly, this study was designed and validated a sensitive and rapid bioanalytical HPTLC method to determine SUV in human urine samples for the very first time. The densitometric measurement of SUV and the internal standard (IS; sildenafil) was performed on glass-coated silica gel normal-phase-60F254S TLC plates using a mixture of chloroform and methanol (97.5:2.5 v/v) as the eluent system. Both the SUV and IS were detected at a wavelength of 254 nm. Both analytes were extracted using the protein precipitation technique utilizing methanol as the solvent. For the IS and SUV, the Rf values were 0.09 and 0.45, respectively. The proposed bioanalytical method for SUV was linear in the 50-1600 ng/band range. The current bioanalytical technique was linear, precise (% RSD = 3.28-4.20), accurate (% recovery = 97.58-103.80), robust (% recovery = 95.31-102.34 and % RSD = 2.81-3.15), rapid, and sensitive (LOD = 3.73 ng/band and LOQ = 11.20 ng/band). These findings suggested that the current bioanalytical method can be regularly used to determine SUV in wide varieties of urine samples.

Updated Review on Clinically-Relevant Properties of Delafloxacin

The extensive use of fluoroquinolones has been consequently accompanied by the emergence of bacterial resistance, which triggers the necessity to discover new compounds. Delafloxacin is a brand-new anionic non-zwitterionic fluoroquinolone with some structural particularities that give it attractive proprieties: high activity under acidic conditions, greater in vitro activity against Gram-positive bacteria-even those showing resistance to currently-used fluoroquinolones-and nearly equivalent affinity for both type-II topoisomerases (i.e., DNA gyrase and topoisomerase IV). During phases II and III clinical trials, delafloxacin showed non-inferiority compared to standard-of-care therapy in the treatment of acute bacterial skin and skin structure infections and community-acquired bacterial pneumonia, which resulted in its approval in 2017 by the Food and Drug Administration for indications. Thanks to its overall good tolerance, its broad-spectrum in vitro activity, and its ease of use, it could represent a promising molecule for the treatment of bacterial infections.

A Rapid and Sensitive Stability-Indicating Eco-Friendly HPTLC Assay for Fluorescence Detection of Ergotamine

Eco-friendly liquid chromatographic methods for measuring ergotamine (EGT) are scant in the published database. Accordingly, the goal of the current study was to develop a high-performance thin-layer chromatography (HPTLC) method for fluorescence detection of EGT in commercially available tablets. This approach was based on the application of ethyl alcohol-water (80:20 v/v) as the eco-friendly eluent mixture. The fluorescence detection of EGT was carried out at 322 nm. The greenness score of the present approach was evaluated by "Analytical GREENness (AGREE)" technology. The present approach for measuring EGT in the 25-1000 ng band^-1 range was linear. The present assay for fluorescence detection of EGT was validated successfully by ICH guidelines for various parameters. The method was found to be rapid, sensitive, eco-friendly, and stability-indicating. The computed AGREE index for the current strategy was 0.84, displaying outstanding greenness features. The present methodology successfully separated the EGT degradation products under forced-degradation circumstances, exhibiting its stability-indicating qualities and selectivity. An amount of 99.33% of EGT was found in commercial formulations, indicating the validity of the current method for pharmaceutical analysis of EGT in commercial products. The results showed that EGT in commercial products might be regularly measured by the existing method.

Green NP-HPTLC and green RP-HPTLC methods for the determination of thymoquinone: A contrast of validation parameters and greenness assessment

INTRODUCTION

Thymoquinone (TQ) is a naturally derived bioactive compound with several therapeutic effects.

OBJECTIVE

The highly sensitive, rapid and green normal-phase (NP)/reversed-phase (RP) high-performance thin-layer chromatography (HPTLC) densitometry technique was developed for the determination of TQ in various plant extracts of different geographical regions, commercial capsules, creams and essential oils.

METHODOLOGY

The NP densitometry estimation of TQ was performed using a cyclohexane-ethyl acetate (90:10, v/v) green solvent system, while, the RP-densitometry estimation of TQ was performed using an ethanol-water (80:20, v/v) green solvent system. The estimation of TQ was conducted at 259 nm.

RESULTS

The NP and RP densitometry techniques were observed linear in the range of 25-1000 and 50-600 ng/band, respectively. All validation parameters such as accuracy, precision, robustness and sensitivity of NP/RP densitometry were observed within the limit of regulatory requirements and hence found to be suitable for the determination of TQ. The TQ contents were found to be highest in the Saudi Arabian extract followed by the Syrian extract, Indian extract, commercial capsules, commercial creams, Jordanian extract, Egyptian extract, Palestinian extract and commercial essential oils using NP densitometry. The TQ contents were found in same order using RP densitometry, but they were much lower than those recorded using NP densitometry. The Analytical GREEnness (AGREE) scores of NP and RP densitometry were found to be 0.82 and 0.84, respectively, suggesting an excellent greenness profile.

CONCLUSIONS

Based on these results, NP/RP densitometry was found to be suitable for the pharmaceutical assay of TQ.

A Greener Stability-Indicating High-Performance Thin-Layer Chromatography Approach for the Estimation of Topiramate

Despite various reported analytical methods for topiramate (TPM) analysis, greener analytical approaches are scarce in literature. As a consequence, the objective of the current research is to design a normal-phase stability-indicating high-performance thin-layer chromatography (SI-HPTLC) methodology for TPM analysis in marketed tablet dosage forms that is rapid, sensitive, and greener. TPM was derivatized densitometrically and analyzed at 423 nm in visible mode with anisaldehyde-sulfuric acid as the derivatizing agent. The greener SI-HPTLC technique was linear in the 30–1200 ng band⁻¹ range. In addition, the suggested SI-HPTLC methodology for TPM analysis was simple, rapid, cheaper, precise, robust, sensitive, and environmentally friendly. The greener SI-HPTLC method was able to detect TPM along with its degradation products under acid, base, and oxidative degradation conditions. However, no TPM degradation was recorded under thermal and photolytic stress conditions. TPM contents in commercial tablet dosage forms were recorded as 99.14%. Using 12 different principles of green analytical chemistry, the overall analytical GREEnness (AGREE) score for the greener SI-HPTLC method was calculated to be 0.76, confirming the proposed normal-phase SI-HPTLC method’s good greener nature. Overall, these results demonstrated that the suggested SI-HPTLC technique for TPM measurement in pharmaceutical products was reliable and selective.

Determination of Thymol in Commercial Formulation, Essential Oils, Traditional, and Ultrasound-Based Extracts of Thymus vulgaris and Origanum vulgare Using a Greener HPTLC Approach

In the literature, greener analytical approaches for determining thymol in its commercial formulations, plant-based phytopharmaceuticals, and biological fluids are scarce. As a result, the goal of this study is to develop and validate a normal-phase "high-performance thin-layer chromatography (HPTLC)" method for determining thymol in commercial formulations, essential oils, traditional extracts (TE), and ultrasound-based extracts (UBE) of Thymus vulgaris and Origanum vulgare obtained from various geographical regions. The greener mobile phase for thymol analysis was a binary combination of cyclohexane and ethyl acetate (85:15, v/v). The derivatized densitometric analysis of thymol was carried out under visible mode at 530 nm utilizing anisaldehyde-sulfuric acid as a derivatizing/visualizing agent. In the 10-2000 ng/band range, the greener normal-phase HPTLC method was linear. Furthermore, for thymol analysis, the proposed analytical approach was simple, quick, inexpensive, accurate, precise, robust, sensitive, and greener. The thymol contents in commercial formulation were computed as 7.61% w/w. In general, the thymol contents were maximum in essential oils of T. vulgaris and O. vulgare compared to the other sample matrices studied. The thymol contents of TE of T. vulgaris and O. vulgare of different geographical regions were significantly low compared to their UBE extract. Using 12 distinct components of green analytical chemistry, the overall "analytical GREEnness (AGREE)" scale for the proposed analytical approach was computed 0.79, showing the good greener nature of the proposed analytical approach. Overall, the greener normal-phase HPTLC technique was found to be reliable for determining thymol in commercial formulations and plant-based phytopharmaceuticals.

A Greener HPTLC Approach for the Determination of β-Carotene in Traditional and Ultrasound-Based Extracts of Different Fractions of Daucus carota (L.), Ipomea batatas (L.), and Commercial Formulation

Various analytical approaches for determining β-carotene in vegetable crops and commercial dosage forms have been documented. However, neither the qualitative nor quantitative environmental safety and greener aspects of the literature analytical methodologies of β-carotene analysis have been assessed. As a result, the goal of this research is to develop and validate a reversed-phase “high-performance thin-layer chromatography (HPTLC)” approach for determining β-carotene in traditional (TE) and ultrasound-assisted (UBE) extracts of different fractions of Daucus carota (L.), Ipomea batatas (L.), and commercial formulation. The greener mobile phase for β-carotene analysis was a ternary mixture of ethanol, cyclohexane, and ammonia (95:2.5:2.5, v v v−1). The detection of β-carotene was done at a wavelength of 459 nm. In the 25–1000 ng band−1 range, the greener reversed-phase HPTLC approach was linear. Other validation factors for β-carotene analysis, including as accuracy, precision, robustness, and sensitivity, were likewise dependable. The contents of β-carotene were found to be maximum in hexane: acetone (50:50%) fractions of TE and UBE of D. carota and I. batatas compared to their acetone and hexane fractions. The amount of β-carotene in hexane: acetone (50:50%) portions of TE of D. carota, I. batatas and commercial formulation A was estimated to be 10.32, 3.73, and 6.73 percent w w−1, respectively. However, the amount of β-carotene in hexane: acetone (50:50%) portions of UBE of D. carota, I. batatas and commercial formulation A was estimated to be 11.03, 4.43, and 6.89 percent w w−1, respectively. The greenness scale for the proposed HPTLC strategy was calculated as 0.81 using the “analytical GREEnness (AGREE)” method, indicating that the proposed HPTLC methodology has good greenness. The UBE approach for extracting β-carotene outperformed the TE procedure. These results indicated that the greener reversed-phase HPTLC approach can be utilized for the determination of β-carotene in different vegetable crops, plant-based phytopharmaceuticals, and commercial products. In addition, this approach is also safe and sustainable due to the utilization of a greener mobile phase compared to the toxic mobile phases utilized in literature analytical approaches of β-carotene estimation.

Highly Sensitive and Ecologically Sustainable Reversed-Phase HPTLC Method for the Determination of Hydroquinone in Commercial Whitening Creams

Hydroquinone (HDQ) is a natural depigmenting agent, which is commonly used in skin-toning preparations. The safety and greenness of analytical methods of HDQ quantification were not considered in previous literature. Therefore, a highly sensitive and ecologically greener reversed-phase high-performance thin-layer chromatography (RP-HPTLC)-based assay was established for HDQ estimation in four different commercial whitening creams (CWCs). The binary ethanol–water (60:40, v·v−1) mixture was utilized as the green solvent system. The estimation of HDQ was carried out at 291 nm. The present RP-HPTLC-based assay was linear in the 20–2400 ng band−1 range. The present analytical method was highly sensitive based on the detection and quantification data. The other validation parameters, such as accuracy, precision, and robustness, were also suitable for the determination of HDQ. Maximum HDQ quantities were obtained in CWC A (1.23% w·w−1) followed by CWC C (0.81% w·w−1), CWC D (0.43% w·w−1), and CWC B (0.37% w·w−1). The analytical GREEnness (AGREE) score for the present analytical method was estimated as 0.91, indicating the excellent greener characteristics of the present RP-HPTLC assay. These results suggest that the present analytical method is highly sensitive and ecologically sustainable for the quantitation of HDQ in its commercial formulations.

Eco-Friendly UPLC-MS/MS Quantitation of Delafloxacin in Plasma and Its Application in a Pharmacokinetic Study in Rats

A novel UPLC-MS/MS assay was developed for rapid quantification of delafloxacin (a novel fluoroquinolone antibiotic in plasma samples by one step sample cleanup procedure. Delafloxacin (DFX) and internal standard (losartan) were separated on a UPLC BEH C18 column (50 × 2.1 mm; 1.7 μm) by using gradient programing of a mobile phase containing 0.1% formic acid in acetonitrile and 0.1% formic acid in water. The quantification was performed by a using triple-quadrupole mass detector at an electrospray ionization interface in positive mode. The precursor to the product ion transition of 441.1 → 379.1 for the qualifier and 441.1 → 423.1 for the quantifier was used for DFX monitoring, whereas 423.1 → 207.1 was used for the internal standard. The validation was performed as per guidelines of bioanalytical method validation, and the evaluated parameters were within the acceptable range. The greenness assessment of the method was evaluated by using AGREE software covering all 12 principles of green analytical chemistry. The final score obtained was 0.78, suggesting excellent greenness of the method. Moreover, Deming regression analysis showed an excellent linear relationship between this method and our previously reported method, and it is suitable for high-throughput analysis for routine application. The proposed method was effectively applied in a pharmacokinetic study of novel formulation (self-nanoemulsifying drug delivery systems) of DFX in rats.

A Sustainable Reversed-Phase HPTLC Method for the Quantitative Estimation of Hesperidin in Traditional and Ultrasound-Assisted Extracts of Different Varieties of Citrus Fruit Peels and Commercial Tablets

Hesperidin (HSP) is a bioactive flavanone glycoside, present abundantly in the variety of citrus fruits. The environmental safety and sustainability of the reported analytical assays of HSP analysis have not been considered in the literature. Hence, a sensitive and sustainable “reversed-phase high-performance thin-layer chromatography (RP-HPTLC)” method has been developed and validated for HSP analysis in traditional (TE) and ultrasound-based (UBE) extracts of four different varieties of citrus fruit peels and its commercial tablet dosage forms. The binary combination of green solvents such as ethanol-water (50:50, v v−1) was used as the mobile phase. The detection of HSP was performed at 287 nm. The sustainable RP-HPTLC method was linear in 20–2000 ng band−1 range. The studied validation parameters, including accuracy, precision, robustness, sensitivity were acceptable for HSP analysis. The content of HSP in TE of four different varieties of citrus fruits including grapefruit peels (Citrus paradisi), mosambi peels (Citrus limetta), lemon peels (Citrus lemon), and orange peels (Citrus sinensis) was detected as 8.26, 6.94, 5.90, and 6.81% w w−1, respectively. The content of HSP in TE of commercial formulations A and B was detected as 5.31 and 5.55% w w−1, respectively. However, the content of HSP in UBE of grapefruit peels, mosambi peels, lemon peels, and orange peels was detected as 11.41, 8.86, 7.98, and 8.64% w w−1, respectively. The content of HSP in UBE of commercial formulations A and B was detected as 6.72 and 6.92% w w−1, respectively. The greenness score of the sustainable RP-HPTLC method was predicted as 0.83 using analytical GREEnness (AGREE) metric approach, indicated the excellent greenness profile of the RP-HPTLC method. UBE procedure for HSP was superior over its TE procedure. These observations and results suggested that the present RP-HPTLC method can be successfully used for the quantitative estimation of HSP in the variety of citrus fruit peels and its commercial formulations. In addition, this method is simple, rapid, precise, accurate, and economical compared to the reported analytical methods of HSP analysis. It is also safe and sustainable method due to the use of ethanol-water solvents systems, as both the solvents are green solvents compared to the solvents used in reported analytical methods of HSP analysis.

Establishment of a dual-aptasensor for simultaneous detection of chloramphenicol and kanamycin

Aptamers, as single-stranded DNA or RNA fragments, have been widely applied as the bio-recognition element for fabrication of flexible and reliable aptasensors to be used in food safety control, clinical therapy and diagnosis and environment monitoring fields. With increasingly fierce antibiotics resistance appearing as a worldwide problem, a highly efficient method is urgently needed to detect antibiotics residues in animal-sourced food. Herein, a simply operated aptasensor based on quantitative real-time PCR (qRT-PCR) was fabricated to realise the simultaneous detection of two antibiotics (i.e. chloramphenicol and kanamycin). The limit of detection (LOD) of 6.13 ng/mL for chloramphenicol and of 19.17 ng/mL for kanamycin of this dual-aptasensor were achieved. Actually, such LOD values were not as good as that of an aptasensor individually established for each antibiotic. The circular dichroism analysis suggested that in the dual-aptasensor, adjacent aptamers might disturb each other's binding with their respective target. Although certain detection sensitivity was lost, the dual-aptasensor could still fulfil the detection requirements, and more importantly, it would improve the detection efficiency. Finally, this dual-aptasensor was applied for detecting chloramphenicol and kanamycin in real spiked food samples, and results indicated good recovery rates. These results demonstrated this developed dual-aptasensor to be a promising highly efficient method with low cost for simultaneous detection of chloramphenicol and kanamycin residues in animal-sourced food samples.

Quantitative Analysis of Emtricitabine in Dosage Forms Using Green RP-HPTLC and Routine NP-HPTLC Methods-A Contrast of Validation Parameters

In this research, an antiviral drug emtricitabine (ECT) was quantified using the validated green reversed-phase high-performance thin-layer chromatography (RP-HPTLC) and routine normal-phase HPTLC (NP-HPTLC) methods in the marketed oral solutions and capsules. Green RP-HPTLC-densitometry quantification was performed using the acetone/water (70:30, v/v) solvent system as the mobile phase. Routine NP-HPTLC-densitometry quantification was performed using the chloroform/methanol (85:15, v/v) solvent system as the mobile phase. The detection was performed at λmax-285 nm for both of the methods. Both densitometry methods were validated for different parameters. Most of the validation parameters including linearity, precision, accuracy, detection, and quantification limits for the green densitometry method were found to be superior compared to the routine densitometry technique. The ECT contents of commercial oral solution and commercial capsules were found to be 100.85 and 98.27%, respectively, using the green densitometry technique. The ECT contents of oral solutions and capsules were 97.16 and 95.54%, respectively, using the routine densitometry technique. Accordingly, the green densitometry technique was found to be better than the routine densitometry technique for ECT assays. Thus, the green densitometry technique can be successfully applied for the quantitation of ECT in the marketed formulations.

Determination of Delafloxacin in Pharmaceutical Formulations Using a Green RP-HPTLC and NP-HPTLC Methods: A Comparative Study

In this work; delafloxacin (DLFX) was determined using a validated green RP-HPTLC and NP-HPTLC methods in commercial tablets and in-house developed solid lipid nanoparticles (SLNs). RP-HPTLC determination of DLFX was performed using "RP-18 silica gel 60 F254S HPTLC plates". However; NP-HPTLC estimation of DLFX was performed using "silica gel 60 F254S HPTLC plates". For a green RP-HPTLC method; the ternary combination of ethanol:water:ammonia solution (5:4:2 v/v/v) was used as green mobile phase. However; for NP-HPTLC method; the ternary mixture of ethyl acetate: methanol: ammonia solution (5:4:2 v/v/v) was used as normal mobile phase. The analysis of DLFX was conducted in absorbance/reflectance mode of densitometry at λmax = 295 nm for both methods. RP-HPTLC method was found more accurate, precise, robust and sensitive for the analysis of DLFX compared with the NP-HPTLC method. The % assay of DLFX in commercial tablets and in-house developed SLNs was determined as 98.2 and 101.0%, respectively, using the green RP-HPTLC technique, however; the % assay of DLFX in commercial tablets and in-house developed SLNs was found to be 94.4 and 95.0%, respectively, using the NP-HPTLC method. Overall, the green RP-HPTLC method was found superior over the NP-HPTLC. Therefore, the proposed green RP-HPTLC method can be successfully applied for analysis of DLFX in commercial tablets, SLNs and other formulations containing DLFX.

Quantitative determination of canagliflozin in human plasma samples using a validated HPTLC method and its application to a pharmacokinetic study in rats

Canagliflozin (CNZ) is the first sodium-glucose co-transporter-2 inhibitor approved for treatment of type 2 diabetes mellitus. In the proposed work, a sensitive, rapid and validated high-performance thin-layer chromatography (HPTLC) method was established for the estimation of CNZ in human plasma for the first time. HPTLC analysis of CNZ and internal standard (sildenafil) was performed on glass coated silica gel 60 F₂₅₄ HPTLC plates using a binary mixture of chloroform-methanol 9:1 (%, v/v) as the mobile phase. Densitometric detection was done at 295 nm. Retardation factor values were obtained as 0.22 and 0.52 for the CNZ and the IS, respectively. The linearity range of CNZ was obtained as 200-3,200 ng/ml. A simple protein precipitation method was used for the extraction of analyte from plasma using methanol. The proposed HPTLC technique was validated for linearity, accuracy, precision and robustness. The proposed HPTLC technique was successfully utilized for the assessment of pharmacokinetic profile of CNZ in rats after oral administration. After oral administration, the peak plasma concentration of CNZ was obtained as 1458.01 ng/ml in 2 h. The proposed HPTLC method could be applied to the study of the pharmacokinetic profile of pharmaceutical formulations containing CNZ.