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Tetracyclines are frequently employed in animal husbandry. Bromhexine is a mucolytic drug that improves the efficacy of tetracyclines. It has been reported that residues of tetracyclines in milk may have negative effects on humans. Two versatile and accurate methods were developed for concurrent analysis of oxytetracycline (OTC) and bromhexine (BR) residues in spiked milk samples. Sample preparation was carefully considered for extraction and cleanup using the ecofriendly chemicals acetic acid, 0.1 N EDTA and ethanol or methanol. The first method was a TLC-densitometric method in which TLC plates previously treated with 10% EDTA (pH 9 with 40% sodium hydroxide) were used as a stationary phase. A solvent mixture of methanol : methylene chloride : 2% aqueous acetic acid (8 : 2 : 0.5, by volume) was the developing system, and detection was carried out at 254 nm. Metformin was used as the internal standard, and linearity was achieved in the ranges of 0.2–10 and 0.04–2 μg per band for OTC and BR, respectively. The second method was a RP-HPLC method; separation was performed on a C18 column using an isocratic mixture of ethanol : 7.5% aqueous acetic acid (70 : 30, v/v). Separation was achieved within 10 minutes, and linearity was proven in the ranges of 0.05–50 and 0.05–30 μg mL−1for OTC and BR, respectively. Diclofenac sodium was used as an internal standard. The proposed methods were validated in accordance with the FDA Center for Veterinary Medicine guidelines. Moreover, the performance and health and environmental impacts of the methods were evaluated using several greenness metrics, namely, the National Environmental Methods Index (NEMI), modified NEMI, Green Analytical Procedure Index (GAPI), Analytical Eco-Scale and Analytical GREEnness (AGREE) metric approaches. All the obtained results proved the validity of the developed methods concerning its performance and ecological effects. The methods can be used to investigate the presence of OTC residues in various marketed milk samples to maintain public health.

Three simple, sensitive, and validated methods were developed for the quantitative determination of fosinopril sodium (FOS) and hydrochlorothiazide (HCZ) in the presence of an HCZ impurity, chlorothiazide (CZ). The first method (I) was the ratio difference spectrophotometric method (RD), in which a standard spectrum of 8 μg mL-1HCZ was used as a divisor, and the difference in amplitude values at 204.6 and 231.2 nm and 290 and 302.6 nm was used for the determination of FOS and CZ, respectively. Meanwhile, for the determination of HCZ, a standard spectrum of 6 μg mL-1CZ was the chosen divisor, and the amplitude difference at 275 nm and 293.6 nm was selected for the calculation of its concentrations. The second method (II) was mean centering of ratio spectra spectrophotometric method (MCR), which depended on the implementation of the mean-centered ratio spectra in two successive steps and the measurement of the amplitudes of the mean-centered second ratio spectra at 243.4 nm for CZ and peak-to-peak amplitudes at 215.6 and 215.8 nm for FOS and at 223.8 and 224 nm for HCZ. On the other hand, the third method (III) was thin-layer chromatography (TLC)—densitometry at which the chromatographic separation of this ternary mixture was performed using pre-activated silica gel 60 F254TLC plates and a developing system mixture consisting of ethyl acetate—chloroform—methanol—formic acid (60:40:5:0.5, by volume) with ultraviolet (UV) scanning at 215 nm. The developed methods were validated according to the International Conference of Harmonization (ICH) guidelines and were successfully used for the determination of FOS and HCZ in their pharmaceutical formulations. Also, a statistical comparison between the developed methods and the reported HPLC method was attained. Using Student’ s t-test and F-test, the results confirmed that there was not any significant difference between them regarding accuracy and precision.

Two validated, simple, and precise chromatographic methods were described for the determination of vildagliptin (VIL) and metformin (MET) in the presence of metformin toxic impurity, melamine (MEL). Method 1 is thin-layer chromatography (TLC)—densitometric method, at which methanol—chloroform—formic acid (7:3:0.3, by volume) was used as the developing system, and separation was carried out on Merck TLC silica gel 60 F254aluminum sheets. The developed plates were air-dried and scanned at 215 nm. Linearity was constructed in the range of 0.2–2.6, 0.4–4.5, and 0.05–1.4 µg per band of VIL, MET, and MEL, respectively. Method 2 is reversed-phase ultra-performance liquid chromatography (RP-UPLC), where the separation was performed on a C18 column using methanol-acetonitrile—0.01 msodium dihydrogen phosphate solution containing 50% 0.01 msodium lauryl sulfate, pH = 5 with H3PO4as the mobile phase at a flow rate of 1 mL min−1at 205 nm. The calibration curves showed good linear relationships in the concentration ranges of 1–50, 2–70, and 0.5–30 µg mL−1of VIL, MET, and MEL, respectively. The developed methods were applied to Galvus Met® tablets, and no interference from excipients was observed. The methods were validated as per the International Conference on Harmonisation (ICH) guidelines, and they compared favorably with the reported one.

Three accurate, sensitive, simple, and precise spectrophotometric methods along with thin-layer chromatography (TLC)–densitometric method were developed, optimized, and validated for the determination of folic acid in the presence of its two impurities (photodegradation products), namely, pteroic acid and para-aminobenzoic acid. Method A is the ratio difference spectrophotometric method (RDSM) which depends on measuring the difference value in the ratio spectrum, where the difference between 291 and 313 nm was used for the determination of folic acid, while the difference between 305 and 319 nm was selected for the estimation of para-aminobenzoic acid; on the other hand, pteroic acid can be determined using the first derivative of ratio spectra spectrophotometric method at 262 nm. Method B is the double-divisor spectrophotometric method (DDSM); this method is based on using the ratio spectrum obtained by the division of the spectrum of ternary mixture by the spectrum of binary mixture containing two of the three mentioned components, and in this method, folic acid, para-aminobenzoic acid, and pteroic acid were measured at 242, 313, and 258 nm, respectively. Method C is the mean-centering of ratio spectra spectrophotometric method (MCR); in this method, folic acid, para-aminobenzoic acid, and pteroic acid can be measured using the mean-centered second ratio spectra amplitudes at 317–318 (peak to peak), 264–265 (peak to peak), and 232 nm, respectively. Lastly, method D is a TLC—densitometric one that depends on the separation and quantification of the mentioned components on TLC silica gel 60 F254plates, using methanol—iso-propanol—water—acetic acid (9:0.5:0.5:0.2, by volume) as the developing system, followed by densitometric measurement of the separated bands at 280 nm. Method validation was carried out according to the International Conference on Harmonisation (ICH) guidelines, and the proposed methods were successfully applied to the analysis of folic acid in pharmaceutical formulations, where no interference from additives has been found. The results obtained by the proposed methods were statistically compared with those obtained by the official reversed-phase high-performance liquid chromatography (RP-HPLC) method, in which no significant difference was observed.

AbstractThree simple, accurate, sensitive and selective spectrophotometric stability-indicating methods for determination of Benztropine Mesylate (BNZ) in the presence of its hepatotoxic and carcinogenic degradation product; Benzophenone (BPH); were developed and validated without preliminary separation. The developed spectrophotometric methods are; first derivative, first derivative of ratio spectra and ratio difference were developed for the determination of BNZ in the presence of BPH in pure form and in pharmaceutical formulation. The most important advantage of this work is that it is the first time to develop spectrophotometric methods for determination of BNZ and its carcinogenic degradation product. BNZ was subjected to stress degradation conditions (acid, alkaline and oxidation), and the obtained degradate was confirmed to be BPH. Calibration curves of these methods are linear over the concentration ranges of 5-20 and 3-20 μg mL−1for BNZ and BPH, respectively. Method (I); first derivative spectrophotometric method where BNZ was measured at 228.2 nm. Method (II); first derivative of ratio spectra spectrophotometric one where the overlapping spectra of BNZ and BPH were well resolved and BNZ was measured at peak amplitude 228.8 nm. Method (III); ratio difference spectrophotometric method which depends on measuring difference in peak amplitude values between two different wavelengths of the ratio spectrum at 224 and 234 nm for determination of BNZ. While BPH was determined by the first derivative at 245 NM without interference from BNZ. The proposed methods were successfully applied for determination of the studied drug in its pharmaceutical formulation. These methods were validated according to ICH guidelines. Results obtained by applying the proposed methods were statistically analyzed and compared with those obtained by reported one using Fand student’s t-tests showed no significant difference was obtained regarding both accuracy and precision.

Dantrolene sodium (DAN) is widely used as a muscle relaxant drug for the treatment of malignant hyperthermia. 5-(4-Nitrophenyl)-2-furaldehyde is reported to be DAN-related compound C (DC), and it is the synthetic precursor of DAN that may be presented as process-related impurity in a pharmaceutical formulation. Also, it is considered to be the acidic and photolytic degradation product of DAN. The synthesis of DC has been performed from p-nitroaniline with good yield and high purity; structure elucidation has been confirmed by infrared (IR), mass spectrometry (MS), and nuclear magnetic resonance (NMR) analyses. In the present study, high-performance thin-layer chromatography (HPTLC) technique was developed and validated for the separation and quantification of DAN along with DC. Separation was carried out on HPTLC silica gel 60 F254plates using a developing system consisting of chloroform—ethylacetate—acetic acid (10:0.5:0.01, by volume) with ultraviolet (UV) scanning at 380 nm. The method was highly sensitive and could be used for the determination of DAN and DC in the range of 0.1–1.5 μg band−1and 0.1–2.0 μg band−1, respectively. The method has been validated in compliance with the International Conference on Harmonization (ICH) guidelines and was successfully applied to a pharmaceutical formulation. The method was compared favorably with the reported British Pharmacopoeia high-performance liquid chromatography (BP HPLC) method.

The presented study was intended to design two validated, simple, and precise chromatographic methods for the determination of chlorzoxazone (CHZ) and diclofenac potassium (DIC) in the presence of chlorzoxazone nephrotoxic degradation product, 2-amino-4-chlorophenol (ACP) which was reported to be its main impurity. Reversed-phase high-performance liquid chromatography (RP-HPLC) was the first method where chromatographic separation was performed on ZORBAX Eclipse Plus C8 column using methanol—water—phosphoric acid (75:25:0.05, by volume) as the mobile phase at a flow rate of 1 mLmin−1. CHZ, DIC, and ACP retention times were found to be 4.26, 7.94, and 3.17, respectively, using photodiode array detector (DAD) at 230 nm. The calibration curves showed good linear relationships in the concentration ranges of 3–45 μg mL−1for CHZ, 3–40 μg mL−1for DIC, and 5–45 μg mL−1for ACP. The second method was thin-layer chromatography (TLC) at which chromatographic separation was carried out on Merck TLC silica gel 60 F254aluminum plates followed by measurement of separated bands at 230 nm and using chloroform—ethanol—triethylamine (9:1:0.1, by volume) as the developing system. The studied components were successfully separated with significantly different RFvalues (CHZ, RF= 0.63; DIC, RF= 0.35; ACP, RF= 0.42). Linearity was constructed in the range of 1.2–5 μg band−1for CHZ, 0.5–4 μg band−1for DIC, and 0.4–4 μg band−1for ACP. The developed methods were applied to Declophen plus® capsules, and no interference from excipients was observed. The methods were validated as per the United States Pharmacopeia (USP) guidelines, and they were compared favorably with the reported method.

AbstractLedipasvir (LED) and Sofosbuvir (SOF) are newly approved antiviral agents co-formulated for treatment of hepatitis C virus (HCV). Up till now, no analytical methods have been published for determination of this pharmaceutically important combination. In this work novel spectrophotometric methods were developed for resolving the partially overlapped spectra of LED and SOF with simple data manipulation and without preliminary separation steps. In method (I), LED was directly determined using its extended spectra at 325 nm where no interference from the co-formulated SOF while the absorption at the isoabsorptive point (λ= 262.4 nm) was used for measuring concentrations of both. By subtraction, concentration of SOF could be obtained. Method (II) is the absorbance subtraction method (AS) at which a mathematically estimated factor representing the absorbance ratio (A262.4/A325) for pure LED was used for simultaneous quantitation of LED and SOF using a unique equation computed at λiso(262.4 n m). Method (III) depended on using ratio spectra and then measuring the amplitude of the constant at 325 nm for LED while using ratio subtraction spectrophotometric method to quantify SOF at 262 nm. Finally, method (IV) was area under the curve correction method (AUCC) at which the areas from 245-265 and 315-335 nm and a mathematically calculated factor for pure LED were used. The methods were validated in compliance to USP guidelines and were successfully applied to available dosage form.

AbstractSimple, precise and economic spectrophotometric and multivariate calibration methods were developed for determination of Paracetamol (PAR), Ascorbic acid (ASC) and Pseudoephedrine hydrochloride (PSH). In method (I) ASC and PSH were determined by applying 1DD spectrophotometric method at 266 and 280 nm for ASC and 218 nm for PSH while PAR was determined by using 1D spectrophotometric method at 257 nm where the linearity ranges are 2-16, 3-40 and 2-28 μg/mL for ASC, PSH and PAR, respectively. While in the developed MCR method the absorption spectra of PAR, ASC and PSH were recorded over 200-400 nm and divided by the spectrum of suitable divisor of PAR, ASC and PSH then the obtained ratio spectra were mean centered. The amplitudes at 287, 286 and 290 nm for PAR, ASC and PSH, respectively were determined where the linearity ranges are 4-20, 3-40 and 2-28 μg/mL for ASC, PSH and PAR, respectively. In method (III) the developed PCR and PLS models were built using a calibration set consisting of seventeen mixtures while the validation set consisted of different eight mixtures in the range of 206-290 nm. The accuracy and precision of the developed methods were proved while their selectivity has been tested by their application for determination of the studied components in different synthetic mixtures. Statistical comparison of the suggested methods with the reported HPLC one using F-and student’s t-tests showed no significant difference.

Accurate, selective, and sensitive thin-layer chromatography (TLC)—densitometry and reversed-phase high-performance liquid chromatography (RP-HPLC) methods have been developed and validated for the simultaneous determination of vitamin E (VIT E) and vinpocetine (VINP) in the presence of the alkaline-induced degradation product of vinpocetine (DEG). The proposed TLC—densitometric method depends on the separation and quantitation of VIT E, VINP, and VINP alkaline-induced degradation product on TLC silica gel 60 F254plates, using methanol—chloroform—ethyl acetate—glacial acetic acid—ammonia solution (6:2:2:0.5:0.1, by volume) as the developing system followed by densitometric measurement at 235 nm. The studied components were well resolved from each other with significantly different RFvalues of 0.81, 0.62, and 0.41 for VIT E, VINP, and DEG, respectively. On the other hand, the developed RP-HPLC method was based on the separation of the studied components using 0.05 M KH2PO4(adjusted to pH = 3) and methanol in gradient elution mode on C8 column at a flow rate of 1.5 mL min−1and ultraviolet (UV) detection at 235 nm. The studied components were well resolved from each other with significantly different Rtvalues of 10.90, 2.89, and 1.90 min for VIT E, VINP, and DEG, respectively. The developed methods were validated according to the International Conference on Harmonization (ICH) guidelines demonstrating good accuracy and precision. The results were statistically compared with those obtained by the reported method, and no significant difference was found. The developed methods are the first developed stability-indicating assay methods (SIAMs) for the analysis of the studied binary mixture.

AbstractTwo selective, accurate, precise and validated spectrophotometric methods were developed for determination of mefenamic acid (MEF) and its two toxic impurities, benzoic acid (BA) and 2, 3 dimethylaniline (DMA) without preliminary separation. The developed methods are direct spectrophotometric method {0D} {Method I}, area under the curve {AUC} {Method II}. In method {I} Mefenamic determine directly by measured absorbance at 350 nm in the range of 2-15 μg/mL. In method {II} the drug was determined by measuring AUC in the wavelength range of 330-370 nm while the impurities could be determined by dividing by of 10 μg/mL MEF then interference from MEF was eliminated by subtracting the amplitude of the constant at 350 nm and then multiplying by the divisor. Then by using AUC at the range 220-230 nm and 235245 nm and by applying in Cramer’s rule, concentrations of BA and DMA could be calculated. The work introduces a low cost and does not need sophisticated steps for determination of MEF, BA and DMA in their powders and in pharmaceutical preparations. The validation of methods was performed according to ICH guidelines regarding accuracy, precision and selectivity. No significance difference was found when these methods were compared to the reported one.

AbstractStability indicating spectrophotometric methods have been developed and validated for determination of Vitamin E (VIT E) and Vinpocetine (VINP) in presence of alkaline induced degradation product of Vinpocetine (DEG) without prior separation. In method (A), two wavelengths were selected for each drug in such a way that the difference in absorbance was zero for the other drugs. Absorbance difference between 217.4 and 234.4 nm were used to determine VIT E while difference between 250.4 and 314.0 nm were selected for VINP determination and the difference between 258.6 and 312.0 nm were selected to determine DEG. In method (B), area under the curve method (AUC) was used for measuring VINP concentration by direct measuring AUC in the range of 330-350 nm, at which no interference from other components. While for determination of VIT E and DEG, the ternary mixture was divided by standard spectrum of 6 μg/mL VINP, in the obtained ratio spectra VIT E and DEG has been directly determined at 210.0 and 230.0 nm, respectively. In method (C), VIT E and DEG were determined by second derivative of ratio spectra (2DD) method by measuring their peak amplitudes at 215.2 and 237.2 nm, respectively, using 6 μg/mL standard spectrum of VINP as a divisor, while the absorbance at isoabsorptive point (λiso=264.4 nm) was used to determine the total concentration of VINP and DEG (where no contribution from VIT E) in the mixture and then by subtraction, VINP concentration could be obtained. The developed methods were validated according to ICH guidelines revealing good accuracy and precision. The results obtained by the proposed methods were statistically compared with those obtained by the reported HPLC methods and no significant difference was obtained. These methods are the first developed SIAM ones for analysis of the studied components.

The electroanalytical sensing of linezolid (LIN) is explored utilising an electrochemical sensing platform based upon a multiwalled carbon nanotubes (MWCNTs)/bromocresol green (BCG) modified carbon paste electrode (MWCNT/BCG/CPE). Cyclic voltammetry, differential pulse voltammetry, chronoamperometry, electrochemical impedance spectroscopy (EIS) and scanning electron microscopy techniques are all used to characterise the properties of the electrochemical sensor. The synergetic effects of BCG and MWCNTs result in an electrocatalytic-type response providing a significantly improved electroanalytical response compared to a bare unmodified CPE. Additionally, the MWCNT/BCG/CPE sensing platform outperforms electrochemical sensors previously reported in the literature with a larger linear response and lower limit of detection. The MWCNT/BCG/CPE electrochemical sensing platform was evaluated towards the sensing of LIN where a linear range from 5.00 × 10−8to 1.45 × 10−4mol L−1with a good linearity and high correlation (0.9968) was observed with the limits of detection and quantification found to correspond to 7.57 × 10−9and 2.50 × 10−8mol L−1respectively. The proposed sensor was applied to the determination of LIN in the presence of cefixime trihydrate (CEF) which are both found in combined dose tablet formulations. The sensor was shown to be successfully applied to the determination of LIN in a pharmaceutical formulation and human urine and saliva samples with satisfactory recoveries. The proposed electrochemical sensing platform is simple and inexpensive and has the potential to be applied to clinical analysis, quality control and the routine determination of drugs in pharmaceutical formulations.

This research article describes a simple and sensitive thin-layer chromatographic (TLC)-densitometric method for simultaneous determination of guaifenesin (GUF) and pseudoephedrine HCl (PSH) in their binary mixtures and in the presence of guaifenesin impurity and related substance, guaiacol. The proposed chromatographic method has been developed using silica gel plates 60 F254as a stationary phase with hexane-acetone-ethyl acetate-triethylamine-water (3:4:3:0.1:0.3, by volume) as a developing system followed by densitometric measurements at 208 (for pseudoephedrine HCl and guaifenesin) and 278 nm (for guaiacol). Experimental conditions have been optimized to get the desired separation and sensitivity. Calibration curves for the three studied components were constructed using polynomial equation which was superior to linear equation with respect to correlation coefficients and quantified ranges (14–25, 2–12, and 0.1–1.1 µg band−1) for pseudoephedrine HCl, guaifenesin and guaiacol, respectively. The developed method has been successfully applied for determination of pseudoephedrine HCl and guaifenesin in Triaminic® Chest Congestion syrup where no interference from syrup additives has been found. The data obtained from method validation confirm the specificity, sensitivity and accuracy of the method. Statistical comparison of the results obtained by the proposed chromatographic method and of those obtained by the reported chemometric technique showed no significant difference at 95% confidence limit.

Ambroxol hydrochloride (AMB), guaifenesin (GUF) and theophylline (THP) are co-formulated together for treatment of common cold and influenza. A newly developed spectrophotometric method; namely; ratio isoabsorptive point and ratio difference in subtracted spectra (RIDSS) spectrophotometric method was applied for resolving this ternary mixture with overlapping spectra in two steps. The proposed method is based on dividing the ternary mixture of the studied drugs by the spectrum of AMB to get the division spectrum, from which concentration of AMB can be obtained by measuring the amplitude values in the plateau region at 310 nm. Then the amplitude value of the plateau region at 310 nm was subtracted from the division spectrum and THP concentration was obtained by measuring the difference in amplitude values at 235 and 268 nm (corresponding to zero difference of GUF) while the total concentration of THP and GUF in the mixture was measured at their isoabsorptive point in the division spectrum at 235 nm (Aiso). GUF concentration is then obtained by subtraction. Validity of the method was tested by application to laboratory prepared mixtures and pharmaceutical formulations containing the studied drugs. Statistical comparison between the results of the proposed method and those of the reported HPLC method showed no significant difference.

Paracetamol (PAR) and methocarbamol (MET) are co-formulated together in Methorelax® tablets which are widely used as a muscle relaxant and in the treatment of muscle-skeletal pain. On the other hand, 4-aminophenol (4-AP) and guaifenesine (GU) have been reported to be related substances and degradation products of PAR and MET, respectively. The target of this work was to develop and validate a simple, sensitive and selective stability indicating RP-HPLC method for the determination of PAR, MET, 4-AP and GU in their bulk powders and laboratory prepared mixtures. Chromatographic separation was achieved within 10 minutes with the required asymmetry, accuracy and precision on ODS column using 0.05 M KH2PO4buffer : acetonitrile (72.5 : 27.5, v/v, pH = 6) as the mobile phase at a flow rate of 1 mL min−1with UV detection at 225 nm. The developed method has been validated as per ICH guidelines and the calibration plots were linear over the concentration ranges of 3–20, 4–25, 0.6–8 and 0.6–8 μg mL−1for PAR, MET, 4-AP and GU, respectively. The method has been successfully applied in the analysis of Methorelax® tablets and good results were obtained. Moreover, its results have been compared to a previously reported RP-HPLC method and no significant difference was found between the two methods.

In this work two well known antihypertensive drugs that are administered in combination and provide greater therapeutic effects than with either drug alone are selectively determined in the presence of their degradation products. Two chemometric methods and TLC-Densitometric one have been developed for the selective determination of Atenolol (ATE) and Chlorthalidone (CLT) along with their hydrolytic degradation products. The developed chemometric models are principal component regression (PCR) and partial least squares (PLS). These models have been updated to be used for prediction of ATE and CLT in another dosage form in which Amiloride HCl (AMH) is included. The updated models are capable of predicting the concentrations of the three components of the new dosage form with good accuracy and precision without reconstruction of the calibration set. The developed TLC-Densitometric method depends upon quantitative densitometric separation of thin layer chromatogram of ATE, CLT, Atenolol degradation product (ATE Deg) and Chlorthalidone degradation product (CLT Deg) using silica gel plates at 227 nm and chloroform: methanol: ethyl acetate: ammonia solution (75: 28: 2: 1.6, by volume) as a developing system. The suggested methods have been used for the determination of the studied drugs in their pharmaceutical formulations and the results were statistically compared to the reported RP-HPLC method.

p-Aminophenol (PAP) is a potentially toxic and mutagenic compound used and/or emitted in industrial, pharmaceutical and agriculture fields. Ion-selective electrode potentiometry (ISE) introduces an effective tool for real-time, portable and direct analysis to overcome lengthy sample preparation, treatment and derivatization steps. The current work aims to develop a portable ISE-potentiometric sensor for direct assay of PAP in industrial, environmental and biological matrices. Sensor assembly included a glassy carbon electrode upon which membrane cocktails were drop-casted. Optimization was carried out using a custom experimental design for the comprehensive evaluation of the main effects of the critical quantitative (percentage of ion-exchanger, PVC to plasticizer ratio and membrane thickness) and qualitative (ionophore type) factors on the sensor performance (Nernstian slope, LOD, LOQ, correlation coefficient). The optimized sensor included 1.20% ion exchanger, PVC: plasticizer ratio 1:4 and calix-[8]-arene as ionophore in 0.07 mm thick PVC membrane. The sensor proved a near-Nernstian slope of 61.9 mV decade?1within a linear range of 2.99 × 10?5?1 × 10?2M, a LOD of 2.86 × 10?5M and rapid response time (1-5 s). The developed method was validated for PAP assay in urine, plasma, water, soil, hair dyes and in paracetamol marketed formulations. Eventually, the developed sensor can have multifarious applications in environmental, clinical and industrial fields.

This study aimed to demonstrate the effect of adding saline to the respirable-solution of salbutamol placed in a nebulization chamber on the clinical status of the ventilated patient.

A plethora of scientific researches has constantly studied the electrochemical detection of different pesticides due to their serious effects on humans. Imidacloprid (IMD) is a pesticide that belongs to the neonicotinoids group. In the current work, a carbon paste electrode (CPE) modified with bismuth ferrite microflowers (BiFeO3/CPE) was used for sensing of IMD in water samples in the presence of fipronil (FIP). The modifier (BiFeO3) was characterized by different techniques. To evaluate the efficiency of the developed electrode towards the detection of both IMD and FIP in water samples, the square wave voltammetry (SWV) technique was employed and spiked water samples were used. The calibration curves were within the range of 1.0–100.0 μM for both analytes. The detection limits (LODs) for IMD and FIP were determined as 0.97 μM and 0.81 μM, respectively. The recovery percentages for IMD and FIP in environmental water samples varied from 90.0%–105.0%. In conclusion, the developed sensor was successfully optimized and can be used for the simultaneous detection of both IMD and FIP in environmental water samples.