Simultaneous Determination of Paracetamol and Caffeine in Human Plasma by LC–ESI–MS

Development of Response Surface Approach for Determination of Paracetamol, Chlorpheniramine Maleate, Caffeine and Ascorbic Acid by Green HPLC Method: A Desirability-Based Optimization

Design of experiment is an efficient and cost-effective tool to optimize the chromatographic separation of a multicomponent mixture. The central composite design was conducted to develop and optimize a green high performance liquid chromatography (HPLC) method for simultaneous quantitation of a quaternary mixture of paracetamol, chlorpheniramine maleate, caffeine and ascorbic acid in their pharmaceutical dosage form as well as the determination of their dissolution profile. A five-level three-factor model was performed to investigate the effect of mobile phase composition, pH and flow rate on enhanced resolution and short run time. Analysis was performed using a Kinitex EVO C18 column and a mobile phase composed of methanol: 0.02 M phosphate buffer pH 3.3 (34:66, v/v) at 1.0 mL/min using photodiode array detection. Optimum chromatographic separation was achieved in <6 min with a desirability of 0.999. Linearity was achieved over a range of 1.00-300.00, 1.00-50.00, 2.00-50.00 and 2.00-100.00 μg/mL for paracetamol, chlorpheniramine maleate, caffeine and ascorbic acid, respectively, with a limit of detection (<0.1 μg/mL). The greenness profile was evaluated using the analytical eco-scale and Analytical GREEnness Metric Approach with values of 81 and 0.77, respectively.

Enhanced fluorimetric detection of diphenylpyraline HCl using micelle and cyclodextrin mediated approach: Spectrofluorimetric and micellar liquid chromatographic application for either single or combined formulation with caffeine and paracetamol

Highly sensitive micellar spectrofluorimetric method (Method I) has been developed and validated for the determination of diphenylpyraline HCl in pharmaceutical tablets and in plasma. Sodium dodecyl sulfate improves the intensity of fluorescence of diphenylpyraline at 286 nm at pH 5 that allow its determination in plasma at nano-level. the mean percent recovery ± S.D was 99.719 ± 0.338 in plasma. In addition, Green cyclodextrin-modified micellar liquid chromatographic method (Method II) has been developed and validated for simultaneous determination of diphenylpyraline, paracetamol and caffeine using cyclodextrin micellar mobile phase consisted of 30 mM Brij*35, 0.5 mM hydroxypropyl β-cyclodextrin and phosphate buffer pH 4: MeOH (95:5, %v/v) that allows their simultaneous determination with enhanced spectrofluorimetric detection of diphenylpyraline. Method II was effectively applied for the simultaneous determination of diphenylpyraline, paracetamol and caffeine in a ternary laboratory prepared mixture which contained all possible excipients with mean percent recoveries ± S.D of 100.176 ± 1.008, 101.166 ± 0.415 and 100.708 ± 1.836, respectively. Linearity range for Method I was 0.1-1 μg. mL^-1 for diphenylpyraline and for Method II was 0.3-50, 25-350, and 0.5-50 for caffeine, paracetamol and diphenylpyraline, respectively. Method I was also applied in spiked human plasma with linearity range 0.2-0.5 μg. mL^-1. The methods are verified to have excellent greenness.

A Simple Stability-Indicating UPLC Method for the Concurrent Assessment of Paracetamol and Caffeine in Pharmaceutical Formulations

A fixed-dose combination of paracetamol (PCM) and caffeine (CAF) tablets/capsules is the most frequently used over-the-counter medicine for fever and headache. In this paper, a simple, reliable, sensitive, rapid, and stability-indicating ultra-performance liquid chromatography (UPLC) analytical method was proposed for simultaneously assessing PCM and CAF in pharmaceutical formulations. The UPLC method was developed on an Acquity UPLC® CSHTM C18 column, and the column oven temperature was maintained at 35 ± 5 °C with isocratic elution by using a solution of methanol and water (30:70, v/v). The maximum absorbance of PCM and CAF was observed at 272.5 nm. The flow rate was 0.2 mL/min, and the injection volume was 1 µL, with the total run time of 2 min for the separation of PCM and CAF. The proposed UPLC method was validated according to the ICH guidelines, and it demonstrated excellent linearity, with correlation coefficients of 0.9995 and 0.9999 over the concentration ranges of 40–400 and 7–70 ng/mL for PCM and CAF, respectively. The mean retention times of 0.82 ± 0.0 and 1.16 ± 0.02 were observed for PCM and CAF, respectively. The limits of detection and quantification were 16.62 and 3.86 for PCM, respectively, and 50.37 and 11.70 for CAF, respectively. PCM and CAF were subjected to acidic, alkali, oxidative, phytochemical, dry-heat, and wet-heat degradation. The method was found to well separate the analytes’ peaks from degradation peaks, with no alterations in retention times. The proposed method is linear, precise, accurate, specific, and robust, and it can indicate stability and be used for the quantitative assessment of pharmaceutical formulations comprising PCM and CAF within a short period of time.

Simultaneous Determination of Caffeine and Paracetamol in Commercial Formulations Using Greener Normal-Phase and Reversed-Phase HPTLC Methods: A Contrast of Validation Parameters

There has been no assessment of the greenness of the described analytical techniques for the simultaneous determination (SMD) of caffeine and paracetamol. As a result, in comparison to the greener normal-phase high-performance thin-layer chromatography (HPTLC) technique, this research was conducted to develop a rapid, sensitive, and greener reversed-phase HPTLC approach for the SMD of caffeine and paracetamol in commercial formulations. The greenness of both techniques was calculated using the AGREE method. For the SMD of caffeine and paracetamol, the greener normal-phase and reversed-phase HPTLC methods were linear in the 50-500 ng/band and 25-800 ng/band ranges, respectively. For the SMD of caffeine and paracetamol, the greener reversed-phase HPTLC approach was more sensitive, accurate, precise, and robust than the greener normal-phase HPTLC technique. For the SMD of caffeine paracetamol in commercial PANEXT and SAFEXT tablets, the greener reversed-phase HPTLC technique was superior to the greener normal-phase HPTLC approach. The AGREE scores for the greener normal-phase and reversed-phase HPTLC approaches were estimated as 0.81 and 0.83, respectively, indicated excellent greenness profiles for both analytical approaches. The greener reversed-phase HPTLC approach is judged superior to the greener normal-phase HPTLC approach based on numerous validation parameters and pharmaceutical assays.

An ultra-rapid drug screening method for acetaminophen in blood serum based on probe electrospray ionization-tandem mass spectrometry

Poisoning incidents caused by drugs, accidental ingestion of poisons, attempted suicide, homicide, and exposure to toxic compounds occur frequently every year across the globe. This raises the need to rapidly identify toxic agents in poisoned patients in a clinical emergency setting. In addition, determining drug/poison concentration is undoubtedly necessary to arrive at a toxicological treatment plan. The purpose of this study was to develop an ultra-rapid drug screening method for the clinical treatment of poisoning. Probe electrospray ionization (PESI), one of the ambient ionization techniques, is able to detect compounds from various biological materials almost directly. We applied the PESI technique to the rapid detection of acetaminophen (APAP). Blood serum samples were diluted 100-fold with 10 mM ammonium formate/ethanol (1:1 v/v) solution including deuterium-labeled internal standards (IS; APAP-d4). Only 10 μL of the diluted sample was used for measurement. The tandem mass spectrometer (MS/MS) equipped with a PESI was used in selected reaction monitoring mode for the quantitation of APAP; the measurement time was only 18 s. Transitions were set at 152 > 110 for quantitation, 152 > 65 for qualifier, and 156 > 114 for IS (APAP-d4). All measurements were conducted in positive mode. The calibration curve (1/x2) was linear over the range of 1.56-200 μg/mL (r2 = 0.998), and the limit of detection and quantitation were 0.37 μg/mL and 1.56 μg/mL, respectively. The accuracy (bias) and precision (RSD%) of the method were within an acceptable range (-0.15-2.8% and 2.3-6.1%, respectively) and matrix effect at 3 concentrations (95.1-104%) indicated that PESI-MS/MS is only slightly affected by matrices. In real forensic cases, quantitative values of APAP determined by the PESI-MS/MS were almost identical to those determined by the liquid chromatography-MS/MS method. Since PESI-MS/MS is a simple, reliable, and rapid determination method for toxic agents with virtually no need for blood serum pre-treatment, it would be highly suitable for poisoning cases in clinical emergency settings. In the future, a method for simultaneous rapid determination of multiple toxic agents will be developed.

Validation thin layer chromatography for the determination of acetaminophen in tablets and comparison with a pharmacopeial method

Adsorption thin layer chromatography (NP-TLC) with densitometry has been established for the identification and the quantification of acetaminophen in three leading commercial products of pharmaceutical tablets coded as brand: P1 (Product no. 1), P2 (Product no. 2), and P3 (Product no. 3). Applied chromatographic conditions have separated acetaminophen from its related substances, namely, 4-aminophenol and and 4′-chloroacetanilide. UV densitometry was performed in absorbance mode at 248 nm. The presented method was validated by specificity, range, linearity, accuracy, precision, detection limit, quantitative limit, and robustness. The TLC-densitometric method was also compared with a pharmacopeial UV-spectrophotometric method for the assay of acetaminophen, and the results confirmed statistically that the NP-TLC-densitometric method can be used as a substitute method. It could be said that the validated NP-TLC-densitometric method is suitable for the routine analysis of acetaminophen in quantity control laboratories.

Determination of glucosamine and carisoprodol in pharmaceutical formulations by LC with pre-column derivatization and UV detection

A simple and reliable precolumn derivatization liquid chromatography method with ultraviolet detection has been developed and validated for the analysis of glucosamine (GS) in various dietary supplement formulations and raw materials. Additionally, the proposed method was used for analysis of carisoprodol (CR) found in ternary mixture with paracetamol (PR) and caffeine (CF). The linearity ranges were 1-100 μg/mL for GS, 1-150 μg/mL for CR, PR and CF. Derivatization was used with 1,2-naphthoquinone-4-sulphonic acid sodium salt in the presence of borate buffer. Chromatographic separation of GS-naphthoquinone derivative was achieved by using a mixture of acetonitrile and water (pH 7.3 adjusted with 0.1 M NaOH) in the ratio 10:90, v/v and flow-rate of 1.0 mL/min. UV detection was carried out at 280 nm. For PR, CF, and CR-naphthoquinone derivative, the chromatographic separation was achieved by using mixture of acetonitrile and 20 mM KH(2)PO(4) (pH 3.0 adjusted with phosphoric acid) in the ratio 20:80, v/v and flow-rate of 1.0 mL/min. UV detection was carried out at 275 nm. The limits of detection were 37.2, 35.9, 30.4 and 40.0 ng/mL for GS, CR, PR and CF, respectively.

The activity and expression of NTPDase is altered in lymphocytes of multiple sclerosis patients

BACKGROUND

Multiple sclerosis (MS) is a demyelinating neurological disease, which is presumed to be a consequence of infiltrating lymphocytes that are autoreactive to myelin proteins. ATP and adenosine contribute to fine-tuning immune responses and NTPDase (CD39) and adenosine deaminase (ADA) are important enzymes in the control of the extracellular levels of these molecules at the site of inflammation. We evaluated the activity and expression of NTPDase and adenosine deaminase (ADA) activity in lymphocytes from patients with the relapsing-remitting form of MS (RRMS).

METHODS

This study involved 22 patients with RRMS and 22 healthy subjects as a control group. The lymphocytes were isolated from blood and separated on Ficoll density gradients and after isolation the NTPDase and ADA activities were determined.

RESULTS

The NTPDase activity and expression were increased in lymphocytes from RRMS patients when compared with the control group (p<0.05). In addition, a decrease in ADA activity was observed in lymphocytes from these patients when compared to the control group (p<0.05).

CONCLUSIONS

The regulation of ATP and adenosine levels by NTPDase and ADA activities may be important to preserve cellular integrity and to modulate the immune response in MS.

Activities of the enzymes that hydrolyze adenine nucleotides in platelets from multiple sclerosis patients

Multiple sclerosis (MS) is the most common chronic disabling neurological disease in young adults. Alterations in platelet function have been observed in MS; however, the mechanism and the relevance of this blood cell disorder with regard to MS pathogenesis are not yet understood. The aim of this study was to evaluate activities of ectonucleoside thiphosphate diphosphohydrolase (NTPDase, CD39), ectonucleotide pyrophosphatase/phosphodiesterase (E-NPP), 5'-nucleotidase and adenosine deaminase (ADA) in platelets from patients with the relapsing-remitting form of MS (RRMS), as well as to analyze platelet aggregation and expression of NTPDase. The results obtained show that NTPDase, 5'-nucleotidase, E-NPP and ADA activities were decreased in platelets of RRMS patients when compared with the control group (p < 0.05). In addition, NTPDase expression in platelets was also decreased in these patients (p < 0.05); however, no differences were observed in platelet aggregation between RRMS patients and the control group. Our results suggest that the alterations in NTPDase, E-NPP, 5'-nucleotidase and ADA may have contributed to the alterations in platelet function in MS by altering the levels of nucleotides and nucleosides in the circulation.