Mean Percentage Recoveries Research Articles

Development of thin layer chromatographic densitometric method for simultaneous quantification of Ivabradine HCl and Bisoprolol fumarate

AbstractThe literature review reveals that no thin‐layer chromatographic method has been developed for the simultaneous estimation of Bisoprolol fumarate and Ivabradine HCl in the combined dosage form. A sensitive, precise, accurate, and robust thin‐layer chromatographic method was developed and validated for the simultaneous quantification of a newer combination of Bisoprolol fumarate and Ivabradine HCl used in the treatment of angina, according to the International Council for Harmonization Q2 (R1) guideline. The stationary phase was pre‐coated silica gel aluminum plate 60 F254 and toluene‒methanol‐triethylamine (9:1:0.1, v/v/v) was used as the mobile phase. A common detection wavelength of 279 nm was selected for the simultaneous quantification of Bisoprolol fumarate and Ivabradine HCl. The method was validated for different parameters like linearity, precision, accuracy, robustness, the limit of detection, and the limit of quantification as per the International Council for Harmonization guidelines. The correlation coefficients (r2) for Bisoprolol fumarate and Ivabradine HCl were found to be 0.9976 and 0.9965, respectively. The mean percentage recoveries for Bisoprolol fumarate and Ivabradine HCl were found to be 99.19%–101.70% and 98.71%–101.86%, respectively. As per the International Council for Harmonization Q2 (R1) guideline, the proposed TLC method was repeatable and selective as per statistical analysis and it can be used for simultaneous estimation of Bisoprolol fumarate and Ivabradine HCl in bulk and formulation.

Quantitative Study of Impurities in Bedaquiline Fumarate: Identification and Characterization of Its Three Degradation Products Using HPLC, LC/ESI-MS, and NMR Analyses

The study aimed to establish a high-performance liquid chromatography (HPLC) method for the quantitative analysis of the related substances of bedaquiline fumarate. Nuclear magnetic resonance and mass spectrometry were used for characterization and assay. A chromatographic method was used for separation. The conditions used were: gradient elution system composed of methanol 0.01mol/L KH2PO4 and 0.01 mol/L K2HPO4 (pH = 4.1) with a flow rate of 1 mL/min, at 224 nm as the detection wavelength. In this study, three degradation products of bedaquiline fumarate have been disclosed for the first time. The related impurities and degradation products of the drug were well separated. The method provided linear responses within the concentration range, which varied from 0.20 to 10.08 μg/mL with limits of detection of 0.10 μg/mL and limits of quantification of 0.20 μg/mL. The mean percent recovery varied between 91.64 and 105.89%. The method was validated for other parameters such as specificity, stability, and robustness. This method was validated and worked well for the impurity studies and quality control analysis of the laboratory-prepared samples of bedaquiline fumarate.

Validated RP-HPLC Method for Estimation of Chrysin in Bulk Form and Nanostructured Lipid Carriers for Topical Application

Background: Chrysin, a flavonoid, occurs naturally in plants and possesses many pharmacological actions, but there is a lack of suitable analytical methods for its estimation. Objective: To develop a simple analytical method and validate it for the estimation of chrysin using reverse phase high-performance liquid chromatography (RP-HPLC). Methods: Isocratic elution was carried out in methanol and 0.1% v/v formic acid in a 70:30 ratio using a C-18 reverse-phase column. The flow rate was set to 1 mL min-1 and the detection wavelength at 268 nm. As per ICH Q2 (R1) guidelines, the developed method was validated in terms of accuracy, precision, system suitability, and robustness. Results: The retention time of Chrysin was found at 10.269 min. In the concentration range of 2-10 μg/mL, the developed method was linear with a regression coefficient (R2) value of 0.998. The mean percentage recovery of chrysin was found within 95-105% at all three levels, which confirms that the developed method was accurate. Moreover, the % RSD was found to be less than 2% confirming that the developed method was precise. The limit of detection and limit of quantification were found to be 0.071 and 0.217 μg/mL. Moreover, the validated method was robust with no significant changes in response to variation in flow rate, mobile phase composition, wavelength, and different lots of columns. Conclusion: It was concluded that the developed method has passed all validation tests and was successfully applied to estimate the presence of Chrysin in bulk as well as in pharmaceutical formulations.

Recovery of Dermatophagoides pteronyssinus (Acariformes: Astigmata: Pyroglyphidae) is influenced by vacuuming protocol, fabric type and the viability of dust mites

Dermatophagoides pteronyssinus (Trouessart, 1897) (Acariformes: Astigmata: Pyroglyphidae) is amongst the most common house dust mites (HDMs) species in Europe. Vacuuming is commonly employed as a method for the recovery for the subsequent quantification of mite densities. The vacuuming protocols employed and their efficiencies are frequently unreported. In this study, a constant-flow vacuum sampler was used to evaluate the recovery of laboratory-reared D. pteronyssinus from cotton, denim or fleece. Two vacuuming protocols were employed. Protocol 1 (P1) entailed a single unidirectional pass of the vacuum head across the fabrics for 60, 90 or 120 seconds. For Protocol 2 (P2), fabrics were vacuumed twice (laterally followed by diagonally) for the same time periods. Vacuuming was carried out on fabrics seeded with live mites (LM), dead mites (DM), and live mites, which were applied to fabric surfaces for 10 minutes and then euthanized by freezing prior to vacuum sampling (EM). There was a significant difference (P<0.001) in mean HDMs recovery with regard to mite viability (LM, DM, EM), fabric type (cotton, denim, fleece), duration of sampling (60, 90, 120s) and vacuuming protocols employed (P1, P2). The numbers of mites recovered from fleece (compared to cotton and denim) were lower for each treatment type where LM and EM were deployed. Overall, the use of protocol 2 resulted in the greatest mean percentage recovery (>80%) of dust mites for all fabrics combined. Recovery rates were also influenced by entrapment of mites (or active attachment) in the fabric microstructure within the weave. The results have implications for the standardisation of mite recovery from fabrics by means of vacuuming.

Separation of ampicillin on polar-endcapped phase: Development of the HPLC method to achieve its correct dosage in cardiac surgery

AbstractThe accurate, simple, and selective reversed phase high performance liquid chromatography (RP-HPLC) has been established and validated for the determination of an antibiotic ampicillin (AMP) in human blood plasma. The SPE extraction was used for the sample preparation. Chromatographic separation was accomplished by a mobile phase containing 15 mM monopotassium phosphate solution of pH 3.3 and methanol (75:25, v/v) in an isocratic mode at a flow rate of 1.4 mL min−1 at 30 °C. The separation was evaluated on a column with a new polar-endcapped C18 stationary phase Arion® Polar C18 or well-known phase Luna® Omega Polar C18. Excellent linearity (R2 0.9998) was shown over range 10–300 mg L−1 with mean percentage recovery 90%. Peak shapes were symmetrical in both columns, Arion® Polar C18 and Luna® Omega Polar C18, with asymmetry factor of 1.0 and 1.4, tailing factor of 1.0 and 1.2, and retention factor of 4.6 and 5.6, respectively. The Arion® Polar C18 was almost 1.4-fold more effective than Luna® Omega Polar C18 phase. The LOQ for ampicillin was achieved 10 mg L−1 for Luna® Omega Polar C18 and 5 mg L−1 for Arion® Polar C18 using 20 µL of a solution containing 0.24 mg mL−1 of cephalexin as an internal standard.A number of articles dealing with the determination of ampicillin is limited, therefore, this study showed the HPLC method suitable for the determination of AMP in human blood plasma from patient who underwent elective cardiac surgical revascularization. In addition, the determination of AMP was also performed for the first time using an Arion® Polar C18 column, which effectively separated AMP from other compounds present in human blood plasma. This new polar-endcapped phase can help in separation of polar antibiotics or other polar compounds, which are unsuccessfully separated on conventional C18 column, and thus can help during method development.

Smart UV Derivative Spectrophotometric Methods for Simultaneous Determination of Metformin and Remogliflozin: Development, Validation and Application to the Formulation

Abstract: Background: The result of pharmaceutical industry research for the new class and the new combination of drugs for the treatments of diabetes is the newly approved combination of metformin (MET) and remogliflozin (REM). For the quality control of this formulation, three smart, reproducible and non-sophisticated spectroscopic techniques were developed by modification of UV spectra. Materials and Methods: The first two methods were based on the measurements of the peak height of the third derivative and second derivative ratio spectra of MET and REM and the third method was the constant center spectrum subtraction method. Results: The proposed methods exhibited Beer’s law in the range of 2.5 to 30 μg/ml and 1 to 24 μg/ml for MET and REM correspondingly by all three methods. The mean percentage recovery was found to be in the range of 99.08% to 100.15% for MET and 98.73% to 100.27% for REM. Further, both analytes were quantified from the formulation using proposed spectroscopic methods with high accuracy. Comparison of all three methods with the reported HPLC method showed no variation in the assay outcomes in relation to accuracy and precision. Conclusion: The suggested techniques are simple, accurate and reproducible, hence could be used for regular quality control of formulation consisting of MET and REM. Key words: Metformin, Remogliflozin, UV, Derivative spectroscopy, Validation, Formulation.

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.

FADI EVALUATION OF THE EFFECTS OF KINESITHERAPY AFTER ANKLE FRACTURE.

The aim of the study was to analyze the values of Foot and Ankle Disability Index (FADI) after kinesitherapy in subjects with bimalleolar or trimalleolar fracture of the ankle after surgery treatment and the obtained values of manual muscle test (MMT) and range of motion (ROM) after rehabilitation, compared with the obtained values of FADI index and on that basis evaluate its possibility in assessing the functionality of the respondents after surgery for bimalleolar or trimalleolar fracture of the ankle. The sample included 60 subjects over the age of 18 who underwent surgery for osteosynthesis due to bimalleolar or trimalleolar fracture of the ankle. All subjects were treated with kinesitherapy as part of the postoperative rehabilitation program. The research was conducted from 2013 to 2018 at the Department of Orthopedics of Dr. Safet MujiÊ Cantonal Hospital in Mostar and Mostar University Clinical Hospital. A statistically significant correlation was found between FADI index values per group and average percentage recovery per MMT (p<0.05), as well as a statistically significant correlation between FADI score values per group and mean percentage ROM value (p<0.05). A statistically significant association was found between mean percentage recovery per ROM and MMT (p<0.05). The conducted research confirmed the working hypothesis of the conducted study. The effects of kinesitherapy after ankle surgery can be evaluated using the FADI index, as well as by manual muscle test and ROM measurement.

A novel analytical method development and validation of estimation of meclizine HCL by UV spectroscopic method

A new simple, accurate, rapid, precise, reproducible and cost-effective spectrophotometric method for the quantitative estimation of Meclizine Hcl. The developed UV spectrophotometric method for the quantitative estimation of meclizine HCl is based on measurement of absorption at maxima wavelength 232nm using Methanol: DMF (40:60). The standard and sample solution were prepared by using Methanol: DMF as a solvent. Quantitative determination of the drug was performed at wavelength range 228-234nm.The linearity was established over the concentration range 5, 10, 15, 20, 25, µg/ml for the meclizine HC l with correlation coefficient value of 0.999 Precision studies showed that 1% relative standard deviation was within range of acceptable limits. The mean percentage recovery was found to be 98.9%. The proposed method has been validated as per ICH guidelines.

Synchronous fluorescence techniques for the detection and monitoring of selected fluorescent dyes in binary and multifluorophoric mixtures

The present study deals with non-destructive conventional emission, constant-wavelength synchronous fluorescence spectroscopy (CWSFS) and first derivative of CWSFS for selective estimation of two fluorescent xanthene dyes viz. rhodamine B (RhB) and fluorescein (Fls) in their binary and multifluorophoric mixtures via spike method in an aqueous environment. Various parameters (Δλ, pH, ionic strength, etc.) affecting these methods were optimized. Based on the results, measurement of RhB and Fls were performed at Δλ, 20.0 nm, pH 7.0, 25.0 ⁰C temperature and scan rate of 240.0 nm/min without their prior separation in mixtures. CWSFS and first derivative CWSFS measurements were carried out at 556.0 nm and 547.0 nm for RhB (R2 = 0.988 and 0.983) and 493.0 nm and 484.0 nm for Fls (R2 = 0.999 and 0.999) over the concentration range of both dyes at 0.10–0.70 mg/L. The mean percentage recoveries from aqueous binary mixtures of RhB and Fls were found to be 98.95, 99.97 (RhB) and 100.68, 100.73 (Fls) for CWSFS and first derivative CWSFS respectively. Results were statistically analyzed in terms of accuracy and precision.

Zero-Biased and Visible Light-Driven Immunosensing of Cardiac Troponin I Biomarker Based on a BiOI/S-g-C3N4/Bi-NaTaO3 Photoelectrochemical Platform

This work describes the development of a platform based on bismuth oxyiodide (BiOI), sulfur-doped graphitic carbon nitride (S-g-C3N4), and bismuth-doped sodium tantalate perovskite (Bi-NaTaO3) for zero-biased photoelectrochemical immunosensing of cardiac troponin I (cTnI) biomarker. The spectroscopic, structural, morphological, and compositional characteristics of the photoelectrochemical (PEC) materials were evaluated by Raman and Fourier-transform infrared spectroscopy (FTIR), powder X-ray diffraction (PXRD), scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDS). Electrochemical impedance (EI) measurements were performed under the incidence and absence of light to investigate the effects of photons on the charge transfer resistance of the photoelectrochemical platform. The influence of the cTnI biomarker on the photoelectrochemical response of the anti-cTnI antibody-modified photoelectrochemical platform (anti-cTnI/BiOI/S-g-C3N4/Bi-NaTaO3/FTO) was evaluated by measuring the photocurrent of the system. The immunosensor presented a linear response range from 1 pg mL-1 to 50 ng mL-1, mean recovery percentage between 95.98 and 99.78% in real human serum samples, and selectivity for the cTnI biomarker.

Factorial design-assisted reverse phase HPLC–UV approach for the concurrent estimation of cetirizine and azelastine in aqueous humor

A new analytical quality by design-assisted HPLC–UV approach is presented, for the first time, for the concurrent determination of cetirizine (CTZ) and azelastine (AZE) in raw materials, commercial eye drops and aqueous humor. The two drugs are co-administered as eye drops in severe ocular allergies. A 23 full factorial design was adopted for the chromatographic optimization to ensure the best analytical performance and reliability, as well as to save time, effort and solvent consumption. The parameters, including pH, acetonitrile ratio, and flow rate, were selected as independent factors. The responses analyzed were resolution and tailing of peaks. The separation was achieved through isocratic elution on C8 column with mobile phase made up of acetonitrile: 0.3% triethylamine of pH 5 (60:40 v/v) at a flow rate of 1.2 mL min−1 and detection at 216 nm. The elution time was less than 6 min. The approach was fully validated in accordance with International Council for Harmonization (ICH) guidelines. Good linearity was achieved over the concentration ranges of 1.0–30 and 0.5–10 µg mL−1 with limits of detection of 0.310 and 0.158 µg mL−1 and limits of quantification of 0.940 and 0.479 µg mL−1 for CTZ and AZE, respectively, with correlation coefficients of 0.9998. The intra- and inter-day precisions were lower than 2%. The good sensitivity of the approach permits the analysis of CTZ and AZE in spiked aqueous humor with mean percentage recoveries of 100.93 ± 1.42 and 100.11 ± 1.55, respectively. The statistical comparison between results of the developed method and the comparison method revealed no differences, indicating the accuracy of the method.

Development of Nanoliposome of Labisia pumila Standardized Extract

Background: Labisia pumila Labisia pumila Labisia pumila Labisia pumila Labisia pumila Labisia pumila Labisia pumila Labisia pumila Labisia pumila has been used traditionally for the treatment of several ailments such as gonorrhoea, dysmenorrhoeaand as tonics for females females.AimsAims: To investigate the standardization procedure of Labisia pumila Labisia pumila Labisia pumila Labisia pumila Labisia pumila Labisia pumila Labisia pumila Labisia pumila Labisia pumila extract (LPE) and evaluation of its nanoliposomes.Methods:Labisia pumila Labisia pumila Labisia pumila Labisia pumila Labisia pumila Labisia pumila Labisia pumila Labisia pumila Labisia pumila Labisia pumila extract was standardized by high performance liquid chromatography (HPLC), and gallic acid, caffeicacid, rutin and 2,4 2,4-Di -tert tert-butylphenol were quantified in the extract. Then, the standardized extract was prepared as nanoliposomeusing soy bean phospholipid by the film method and after that was characterized by zetasizer, zeta potential, UV -Visspectrophotometer and FTIR techniques techniques.Results:For the standardization, the mean percentage recovery values of the concentration studied were 98.49 98.49±1.43, 97.01 97.01±2.04,97.7097.70±1.55 and 99.43 99.43±3.04 % for gallic acid, caffeic acid, rutin and 2,42,4-Di -tert tert-butylphenol, respectively. The accuracy values werebetween 95.06 and 104.86% for the marker compounds, while the corresponding precision values were betwee n 0.09 and 5.18% forwithinwithin-day and between between-day analysis, respectively. The average particle size for LLP was 174.20±4.58 nm with zeta potential ofparticles surface charge from −43.40 to − 44.40 mV. The polydispersity index was 0.19±0.02 and the morpholo gy and presence ofliposomes were further confirmed by transmission electron microscopy which revealed the presence of spherical liposomes of &lt; 200nm.Conclusion:HPLC method for the simultaneous determination of selected marker compounds has been develop ed; the method wasreliable, repeatable and reproducible. The method was successfully applied in standardization of LPE. LPE was successfully pr eparedas nanoliposome using soybean phospholipid.

Development and Validation of RP-HPLC Method for Simultaneous Estimation of Haloperidol and Trihexyphenidyl Hydrochloride in Tablet Dosage Form

Haloperidol is a common antipsychotic drug used to treat schizophrenia, and Trihexyphenidyl hydrochloride is an antiparkinsonian medication. The combination formulation is used to treat schizophrenia as well as depression. A simple, accurate, and precise assay as well as a rapid stability-indicating reversed-phase high performance liquid chromatography (RP-HPLC) method for the simultaneous estimation of Haloperidol (HAL) and Trihexyphenidyl hydrochloride (THP) from their combination drug product have been developed and validated. The proposed method is based on reversed-phase separation of the two drugs using a Zorbax Eclipse XDB C18 column (150 mm x 4.6 mm, 5 um) kept at 30°C. The optimal mobile phase was composed of 0.5 mL triethylamine 0.05 M phosphate buffer having pH 3.75: acetonitrile: (65:35 v/v), a flow rate of 1.2 mL.min-1, and PDA detection at 210 nm. The method was validated in accordance with ICH standards. It was found to be precise and reproducible. Linearity was achieved in the concentration ranges of 6-60 ug mL-1 for HAL and 8-80 ug mL-1 for THP, with correlation coefficients of 0.999 and 1.000, respectively. The mean percent recovery of triplicate samples at each level for both drugs was 99.10-100.7% for Haloperidol and 98.7-100.6% for Trihexyphenidyl hydrochloride. The proposed method can be used to successfully test quality control and stability samples from bulk manufacturing and pharmaceutical dosage forms.

Method of Simultaneous Estimation of Nitazoxanide and Ofloxacin from Bulk and Tablet Dosage Form Using RP-HPLC

For the simultaneous determination of Nitazoxanide and Ofloxacin in tablet dosage form, a simple reverse phase liquid chromatographic method was developed and validated. A mobile phase containing acetonitrile, methanol, and 0.4 M citric acid (60:30:10, v/v/v) was used for the separation. Thermo C18 (4.6mm*250 mm, 5 ) column was used, with a flow rate of 1 mL/min and UV detection at 300 nm. Nitazoxanide and ofloxacin had retention times of 3.071 and 12.47 minutes, respectively. The described method was linear over a concentration range of 5-30 g/mL for Nitazoxanide (r2&gt;0.999) and 2-12 g/mL for Ofloxacin (r2&gt;0.998). The mean percentage recovery for Nitazoxanide was 99.96% and 101.05% for Ofloxacin. Nitazoxanide and Ofloxacin had limits of detection (LOD) of 0.3788 and 0.0929 g/mL, respectively. The limit of quantification (LOQ) for Nitazoxanide and Ofloxacin, respectively, was 1.1479 g/mL and 0.2816 g/mL. The study's findings revealed that the proposed RP-HPLC method is simple, fast, precise, accurate, and cost effective, making it suitable for routine determination of Nitazoxanide and Ofloxacin in bulk and tablet dosage forms.

Smart stability indicating spectrophotometric methods for determination of modafinil: the promising treatment for post-covid neurological syndrome

Modafinil (MDF) is one of the neurostimulants with a potential effect in the COVID-19 ICU ventilated patients and post-COVID neurological syndrome treatment. Four rapid, simple and cost-effective stability indicating spectrophotometric methods were used for estimation of MDF in the presence of its acidic degradation product, namely; ratio difference (RD), first derivative of the ratio spectra (1DD), mean centering (MCR) and ratio subtraction method (RS). These methods were validated according to ICH guidelines and all methods revealed a good linearity in concentration range of (5-30 µg/mL) in addition to a good accuracy and precision with mean percentage recovery of 99.97 ± 0.305 for (RD), 100.10 ± 0.560 for (1DD), 100.02 ± 0.483 for (MCR) & 99.18 ± 1.145 for (RS) method. Specificity of the proposed methods was assessed and MDF was determined in the presence of up to 80% of its acidic degradation product for RD, 1DD, MCR and RS methods. The proposed methods were successfully applied for the determination of MDF in bulk powder and its tablet dosage form with mean percentage recovery of 100.33 ± 0.915 for (RD), 100.62 ± 0.985 for (1DD), 99.70 ± 0.379 for (MCR) and 100.21 ± 0.313 for (RS) method. The results obtained were statistically compared with those of official HPLC method and showed no significant difference with relevance accuracy and precision.

Experimentally designed electrochemical sensor for therapeutic drug monitoring of Ondansetron co-administered with chemotherapeutic drugs

The experimental design extracts valuable information about the main effects and interactions from the least number of experiments. The current work constructs a solid-state sensor for selective assay of Ondansetron (OND) in pharmaceutical dosage form and plasma samples. During optimization, the Design Expert® statistical package constructed a custom design of 15 sensors with different recipes. We fed the software with the experimentally observed performance parameters for each sensor (slope, LOQ, correlation coefficient, and selectivity coefficient for sodium ions). The computer software analyzed the results to construct a prediction model for each response. The desirability function was adjusted to optimize the Nernstian slope, minimize the LOQ and selectivity coefficients, and maximize the correlation coefficient (r). The practical responses of the optimized sensor were close to those predicted by the model (slope = 60.23 mV/decade slope, LOQ = 9.09 × 10–6 M, r = 0.999, sodium selectivity coefficient = 1.09 × 10−3). The sensor successfully recovered OND spiked to tablets and human plasma samples with mean percentage recoveries of 100.01 ± 1.082 and 98.26 ± 2.227, respectively. Results were statistically comparable to those obtained by the reference chromatographic method. The validated potentiometric method can be used for fast and direct therapeutic drug monitoring of OND co-administered with chemotherapeutic drugs in plasma samples.

Smart spectrophotometric methods for enhancement spectral resolution and rapid simultaneous determination of dapoxetine and sildenafil in commercial tablets using fuzzy inference system and continuous wavelet transform

Dapoxetine (DAP) and sildenafil (SIL) have been clinically prescribed for the treatment of premature ejaculation and erectile dysfunction. The analysis of the combination of DAP and SIL has a challenge due to the high overlap spectra of these compounds. In this study, fuzzy inference system (FIS) along with principal component analysis (PCA) and continuous wavelet transform (CWT) methods were combined with UV–Vis spectrophotometry for solving such a challenging overlap and spectral resolution. Hence, simultaneous determination of DAP and SIL was performed in mixtures and pharmaceutical samples using these methods. The mean recovery percentage values of FIS were 98.22% and 98.44% for DAP and SIL, respectively. In addition, the root mean square error (RMSE) of DAP and SIL was found to be 0.158 and 0.933, respectively. The detection limits (LOD) of CWT were 1.134 and 0.179 μg mL−1 for DAP and SIL, respectively. Also, the limit of quantification (LOQ) values of DAP and SIL were 1.169 and 0.238 μg mL−1, respectively. Relative standard deviation (RSD) values related to the real samples were lower than 0.5% for both methods. Statistically, there was no significant difference between results found for the proposed and the high-performance liquid chromatography (HPLC) methods. The result obtained revealed that the suggested methods were found to be precise, accurate, simple, cost-effective, and robust. The present study provides an excellent approach for the concurrent determination of DAP and SIL in combined tablet formulation.

Application of green first derivative synchronous spectrofluorometric method for quantitative analysis of fexofenadine hydrochloride and pseudoephedrine hydrochloride in pharmaceutical preparation and spiked human plasma

Fexofenadine hydrochloride and pseudoephedrine hydrochloride are prescribed in a combined dosage form for the treatment of allergic rhinitis. In the present work, a sensitive synchronous fluorescence spectroscopic method was applied in conjunction with first derivative for quantitative estimation of fexofenadine hydrochloride and pseudoephedrine hydrochloride in pure form, pharmaceutical tablets and spiked human plasma. Fexofenadine hydrochloride showed its conventional emission spectrum at 294 nm when excited at 267 nm. On the other hand, pseudoephedrine hydrochloride showed its conventional emission spectra at 286 nm when excited at 261 nm. The fluorescence intensities were greatly enhanced by the use of sodium dodecyl sulphate as a micellar surfactant. Application of the synchronous mode to measure the fluorescence spectra of the above drugs provided sharp narrowing bands, but the overlap was not completely resolved. Derivatization of the synchronous spectra to the first order completely resolved the overlap of the fluorescence spectra and allowed simultaneous quantitative determination of the drugs under study. Fexofenadine hydrochloride and pseudoephedrine hydrochloride could be determined from their first-order synchronous spectra at 286 and 294 nm, respectively, without interfering with each other. The method showed linearity with an excellent correlation coefficient in the concentration range of 100–1500 ng/mL for Fexofenadine hydrochloride and 50–1000 ng/mL for pseudoephedrine hydrochloride. The method was successfully applied for the simultaneous determination of the studied drugs in pharmaceutical formulation, with mean percent recoveries for Fexofenadine hydrochloride and pseudoephedrine hydrochloride of 99.49 ± 0.931 and 98.67 ± 0.634, respectively, and in spiked human plasma, with mean percent recoveries for Fexofenadine hydrochloride and pseudoephedrine hydrochloride of 95.21 ± 1.938 and 94.89 ± 1.763, respectively. Furthermore, the greenness of the described method was assessed using four different tools namely, the national environmental method index, the analytical eco-scale, the green analytical procedure index and the AGREE evaluation method. The proposed method seemed to be superior to the reported HPLC method with respect to the metrics of the greenness characters.

Development and validation of a method for determination of 17 endocrine disrupting chemicals in milk, water, blood serum and feed by UHPLC-MS/MS

The concern for human exposure to bisphenol A (BPA) has led to the introduction of other bisphenols to be used as substitutes in industrial processes. These compounds show activity similar to BPA as endocrine disruptors and could be already widespread both in the environment and in food. To monitor their possible occurrence in the food chain, an analytical method based on affinity chromatography clean-up and UHPLC coupled to tandem mass spectrometry detection was developed and in-house validated according to European law, for simultaneous determination of 17 bisphenols in milk and blood serum from bovine and buffalo, in drinking water and in feed. The analytical performance parameters of the method for these matrices were determined. The results showed satisfactory precision in terms of relative standard deviation (3.3%–21.4%), overall good trueness as mean percentage recoveries (77.0%–119.4%), with the only exception of bisphenol PH and bisphenol S in milk and BPA diglycidyl ether in serum. The high specificity and sensitivity of the method allowed us to determine the analytes at very low concentrations, that is, 0.01–1.0 ng/mL in water, 0.1–2.0 ng/mL in milk, 0.01–1.0 ng/g in blood serum and 1.0–10.0 ng/g in feed.