Drugs In Pure Forms Research Articles

Eco-friendly, sensitive and inventive first derivative synchronous spectrofluorimetric determination of ciprofloxacin and phenylephrine in their pure form, single and combined eye drops

A facile, sensitive, accurate and green spectrofluorimetric method was evolved for the assay of ciprofloxacin hydrochloride (CFX) and phenylephrine hydrochloride (PLN) in their co-formulated eye drops with their challengeable ratio of 30:1 for CFX and PLN, respectively. Such drops are clinically used for the treatment of eye bacterial infections. They relieve the symptoms of infection by stopping further growth of the causative microorganisms. The assay principle based on first-order synchronous spectrofluorometric scan using Δ λ = 40 nm in which PLN peak amplitudes were recorded at 283.4 nm, meanwhile CFX was measured at 326.2 nm in the same scans. The calibration curves were linear within the concentration ranges: 0.02–0.5 µg/mL and 0.5–5.0 µg/mL for PLN and CFX, respectively. The method validation was confirmed following the International Conference of Harmonization (ICH) Guidelines. This suggested method was the first one that described simultaneous analysis of PLN and CFX by a spectrofluorimetric technique. In this method, green analytical procedures were implemented to lessen occupational and environmental perils and method greenness was assessed by four assessment tools. GAPI, NEMI, AGREE and Analytical eco-scale were applied to this study and it was deduced from their results that the method had high degree of greenness as it fulfilled all requirements of GAPI, NEMI pictograms and it had high scores of analytical eco scale (97) and AGREE methods (0.82). Subsequently, it was successfully applied to assay both drugs in pure forms, pharmaceutical single and co-formulated eye drops.

Greenness assessment of two chromatographic methods developed for the determination of Mupirocin in two binary mixtures along with its impurity

Two simple, accurate and precise chromatographic methods have been developed and validated for estimating Mupirocin (MUP) in two binary mixtures. Mixture (1); with Fluticasone propionate (FLU) together with two of their impurities, namely; Pseudomonic acid-D (Pseud-D) and Fluticasone impurity C (FIC). Mixture (2); with Mometasone furoate (MF) along with Pseud-D impurity. High performance thin layer chromatography (HPTLC-densitometry) and high performance liquid chromatography (RP-HPLC) were the two proposed methods. In the HPTLC method, good separation of both mixtures was achieved by using HPTLC plates pre-coated with silica gel 60 F254 as stationary phase and the mobile phase consisted of toluene: chloroform: ethanol at a ratio of (5: 4: 2, by volume). The detection was carried out at 220 nm for MUP and 254 nm for FLU, MF, Pseud-D and FIC. In the HPLC method, chromatographic separation was carried out using Agilent Eclipse XDB (250 mm×4.6 mm, 5 μm) C18 column. For mixture (1), a mobile phase of methanol: sodium di-hydrogen phosphate (pH 3.0) was applied in stepwise gradient elution starting at ratios of (50: 50, v/v) and then switching to (80: 20, v/v) after 7 min at a flow rate of 1 mL.min− 1. Detection was performed using diode array detector at 220 nm for MUP and Pseud-D and 240 nm for FLU and FIC. For mixture (2), the same mobile phase was used, but in isocratic elution in the ratio (80: 20, v/v) at flow rate of 1 mL.min− 1 and detection at 220 nm for MUP and Pseud-D and 248 nm for MF. The two methods successfully separated the cited drugs and were used to determine the drugs in pure form as well as pharmaceutical dosage forms. Validation was done as per International Council on Harmonization guidelines. Furthermore, the greenness of the proposed methods compared to the reported method, was evaluated as per the National Environmental Method Index, analytical Eco scale, Green Analytical Procedure Index and Analytical Greenness metric approaches.

Green Spectrophotometric Determination of Amoxicillin Anti-Biotic Drug in Pure Form and Pharmaceuticals Using Ninhydrin

An inexpensive, accurate, and simple green spectrophotometric assay was developed and validated for the determination of the antibiotic drug, Amoxicillin (AMX), in pure drug and tablet using ninhydrin (NIH). The method relied on the condensation reaction between the drug and Ninhydrin reagent (NIH) in the present NaHCO3, and then the colored product was measured at 420 nm. The absorbance measured was related to AMX concentration. Different experimental conditions of assay were studied, and optimized. Beer’s law for the method is obeyed over the concentration ranges 30-180 µg mL-1. The molar absorptivity value was 1.76×103 L mol-1 cm1. The limits detection (LOD) and quantification (LOQ) values were 0.9 and 2.73 mg mL-1. The method was validated according to ICH guidelines for precision and accuracy, robustness and ruggedness, and selectivity. The intraday and inter-day relative standard deviation (%RSD) values for precisions were found to be in the range of 1.53–2.62%, whereas the respective relative error (%RE) values for accuracy were better than 2.25%. Robustness and ruggedness were tested, and the %RSD values were within the accepted limits in both instances. Also, placebo blank and synthetic mixture analysis was applied for method selectivity. The results showed that there is no interference resulting from co-formulated materials in the developed method. The assay was successfully applied for the determination of AMX in commercial tablets and capsules with reliable, satisfactory results, and indicated that the proposed method was as accurate and precise as the official methods. Hence, the proposed method can be applied in pharmaceutical laboratories of quality control.

Synchronous spectrofluorimetric determination of favipiravir and aspirin at the nano-gram scale in spiked human plasma; greenness evaluation

Favipiravir and aspirin are co-administered during COVID-19 treatment to prevent venous thromboembolism. For the first time, a spectrofluorometric method has been developed for the simultaneous analysis of favipiravir and aspirin in plasma matrix at nano-gram detection limits. The native fluorescence spectra of favipiravir and aspirin in ethanol showed overlapping emission spectra at 423 nm and 403 nm, respectively, after excitation at 368 nm and 298 nm, respectively. Direct simultaneous determination with normal fluorescence spectroscopy was difficult. The use of synchronous fluorescence spectroscopy for analyzing the studied drugs in ethanol at Δλ = 80 nm improved spectral resolution and enabled the determination of favipiravir and aspirin in the plasma matrix at 437 nm and 384 nm, respectively. The method described allowed sensitive determination of favipiravir and aspirin over a concentration range of 10–500 ng/mL and 35–1600 ng/mL, respectively. The described method was validated with respect to the ICH M10 guidelines and successfully applied for the simultaneous determination of the mentioned drugs in pure form and in the spiked plasma matrix. Moreover, the compliance of the method with the concepts of environmentally friendly analytical chemistry was evaluated using two metrics, the Green Analytical Procedure Index and the AGREE tool. The results showed that the described method was consistent with the accepted metrics for green analytical chemistry.

Application of the green analytical procedure index to the simultaneous analysis of co-formulated tinidazole and ciprofloxacin in pure form, tablet dosage form, and human plasma using an environmentally friendly micellar high-performance thin-layer chromatographic technology

In individuals with chronic refractory pouchitis and other gastrointestinal disorders, the combination of ciprofloxacin (CIP) and tinidazole (TIN) is beneficial and safe. As a result, a green micellar high-performance thin-layer chromatographic (HPTLC) approach for the immediate analysis of TIN and CIP in pure, spiked human plasma, and co-formulated tablet dosage form has been developed. It is rapid, extremely easy, sensitive, cost-effective, and environmentally friendly. The stationary phase was Merck aluminum HPTLC plates covered with silica gel 60 F254, while the mobile phase was acetone–ethanol–2% watery sodium dodecyl sulfate (3:4:2, V/V). For quantification of both medications, the densitometric scanner was set at 310 nm. For TIN and CIP, this chromatographic separation yielded symmetric, compact peaks with RF values of (0.22 ± 0.009) and (0.42 ± 0.007), respectively. At 310 nm, the separated spots were densitometrically scanned. For TIN and CIP, the detection thresholds were 6.7 ng/band and 25.03 ng/band, respectively. For TIN and CIP, the quantification limits were 20.3 ng/band and 75.25 ng/band, respectively. The approach was validated according to International Council for Harmonisation (ICH) principles and then used to determine the researched medicines in their various pharmaceutical dosage forms, and human plasma yielding an exceptional percent of recovery. In terms of precision and accuracy, the results were in great accordance with the published approach. This method is suitable for the sequential analysis of the two drugs in pure form, tablet dosage forms, and spiked human plasma due to its simplicity, speed, greenness, robustness, and low cost.

Spectrophotometric Methods for Determination of Clopidogrel in Bulk and in Pharmaceutical Formulations

The present article reports three simple, sensitive, and accurate spectrophotometric methods which have been progressed for monitoring of clopidogrel bisulphate (CG) in bulk and in pharmaceutical formulations. The three methods are depended on the production of yellow ion-pair complexes between the investigated drug and bromophenol blue (BPB), bromthymol blue (BTB), and bromocresol purple (BCP) as dyes in a universal buffer of pH range (2.0- 4.0). The chloroform was used for formed complexes extraction and measured at 421 nm, 414 nm, and 409 nm, respectively for the three systems. The best conditions of the reactions were tested and optimized. Beer’s law was obeyed in the concentration ranges 2.0 – 18.0 µg mL-1 with molar absorptivity of 4.4 × 104 , 6.4 × 104 and 6.9 × 104 L mol-1cm-1, for the BPB, BTB and BCP methods, respectively. Sandell’s sensitivity, correlation coefficient, quantification and detection limits are also studied. The investigated methods have been achieved successfully for the determination of the drug in pure form and in pharmaceutical formulations. Interference between common pharmaceutical excipients and additives was disappeared. Statistical comparison of the results with those observed by the HPLC method exhibits excellent agreement and shows no significant difference in terms of accuracy and precision.

Green fitted second derivative synchronous spectrofluorometric method for simultaneous determination of remdesivir and apixaban at Nano gram scale in the spiked human plasma

Remdesivir and apixaban have been included in the treatment guidelines of several countries for severe COVID-19 infections. To date, no analytical method has been developed for the determination of remdesivir and apixaban in plasma matrix. The main objective of this work was to develop a highly sensitive, green-adapted spectrofluorometric method for the determination of remdesivir and apixaban at the Nanoscale. Remdesivir and apixaban showed overlapping fluorescence emission spectra at 403 nm and 456 nm when excited at 246 nm and 285 nm, respectively. This overlap was resolved in two steps. The first step was synchronous fluorescence scanning of remdesivir and apixaban, and the second step was manipulation of the second-order derivative for the obtained spectra. These steps allowed complete resolution of the overlapping fluorescence spectra and selective determination of remdesivir and apixaban at 410 and 469 nm, respectively. The variables affecting the synchronous scanning of the aforementioned drugs were optimized in terms of sensitivity parameters and principles of green analytical chemistry. The described method allowed sensitive determination of remdesivir and apixaban over the concentration range of 5–200 ng/mL and 50–3000 ng/mL, respectively. The described method was validated and successfully applied for the simultaneous determination of the mentioned drugs in pure form and in spiked human plasma.

Smartphone as a Portable Detector for Thin-Layer Chromatographic Determination of Some Gastrointestinal Tract Drugs.

Thin-layer chromatography (TLC) is an effective and simple technique for screening, evaluating, and quantifying low-quality and counterfeit pharmaceutical products. Smartphones have recently been used as accessible, cheap, and portable detectors that can replace more complicated analytical detectors. In this work, we have developed a simple and sensitive TLC method utilizing a smartphone charged-coupled device (CCD) camera not only to verify and quantify some gastrointestinal tract drugs, namely, loperamide hydrochloride (LOP) and bisacodyl (BIS), but also to detect acetaminophen (ACT) as a counterfeit drug. Both drugs (LOP and BIS) were chromatographed separately on a silica gel 60 F254 plate as a stationary phase under previously reported chromatographic conditions, using ethyl acetate:methanol:ammonium hydroxide (24:3:1, by volume) and ethyl acetate:methanol:glacial acetic acid (85:10:5, by volume) as developing systems to determine LOP and BIS, respectively. Universal stains, namely, iodine vapors and vanillin, were used to visualize the spots on the TLC plates to get a visual image using the smartphone camera and a spotlight as an illumination source with no need for a UV illumination source. The spot intensity was calculated using a commercially available smartphone application for quantitative analysis of the studied drugs utilizing ″acetaminophen″ as an example of a counterfeit substance. Rf values were calculated using the recorded images and found to be 0.77, 0.79, and 0.74 for LOP, BIS, and ACT, respectively, providing drug identity. Linear calibration curves using the smartphone–TLC method were obtained between the luminance and the corresponding concentrations over the ranges of 2.00–10.00 μg/mL and 1.00–10.00 μg/mL with limits of detection of 0.57 and 0.10 μg/mL for LOP and BIS, respectively. The suggested method was validated according to the International Conference of Harmonization (ICH) guidelines. The method was then successfully applied for the qualitative and quantitative determination of LOP or BIS as an example for gastrointestinal tract drugs in pure form and in their pharmaceutical dosage formulations. The proposed method is considered as a perfect alternative to traditional reported densitometric methods due to its simplicity, easy application, and inexpensiveness. No previously reported methods utilizing smartphones have been published for the determination of the studied drugs. The developed approach is considered the first TLC method using smartphones for the determination of some gastrointestinal tract drugs in their pure form and in pharmaceutical formulations.

Development of novel univariate and multivariate validated chemometric methods for the analysis of dasatinib, sorafenib, and vandetanib in pure form, dosage forms and biological fluids

New precise, responsive and selective univariate and multivariate chemometric spectrophotometric methods were developed and validated for determination of vandetanib (VTB), dasatinib (DTB), and sorafenib (SFB) in pure form, tablets, spiked human (plasma and urine). Determination of these drugs is essential because of their therapeutic benefits. These methods included double divisor ratio spectra derivative univariate method and chemometric multivariate method including partial least-squares (PLS) and principal component regression (PCR). A novel univariate method was developed for the estimation of these drugs. This method depends on the UV-Spectrophotometric data for simultaneous analysis of a ternary overlapped mixture. The Double divisor ratio spectra derivative absorption minima at 358.4 nm was used for quantification of VTB, absorption maxima at 300.3 nm for quantification of DTB and absorption maxima at 259.8 nm for quantification of SFB. This method shown a linearity in the extent of 2–9 μg/mL for VTB and DTB and over the concentration range of 3–9 μg/mL SFB within correlation coefficient (r2) of 0.9999. This method was successfully applied to pure form, tablet dosage form, spiked human (urine and plasma). Chemometric PLS and PCR models were found to be linear in the range of 2–9, 2–9, and 3–9 μg/mL for VTB, DTB and SFB, respectively. These models were estimated using eighteen mixtures as calibration set and seven mixtures as validation set. In the original data, the minimum root mean square error of prediction (RMSEP) was 0.11, 0.09 and 0.09 for VTB, DTB and SFB by PLS and 0.05, 0.04 and 0.03 by PCR while in the derivative data, the RMSEP was 0.09, 0.10 and 0.09 by PLS and 0.06, 0.06 and 0.03, by PCR for VTB, DTB and SFB, respectively. These methods were applied for the determination of the drugs in pure form and dosage form. Updating PLS model permitted the determination of the VTB, DTB and SFB in spiked human urine, plasma and drug-dissolution test of their tablet.

Stability indicating HPLC-Fluorescence detection method for the simultaneous determination of linagliptin and empagliflozin in their combined pharmaceutical preparation

A sensitive, accurate, and precise liquid chromatographic method has been developed and validated for the determination of Linagliptin (LNG) and Empagliflozin (EMP) in their combined tablets. Chromatographic separation was carried out on ODS-3 Inertsil® C18 column (150×4.6 mm, 5 µm). The mobile phase A (consisting of 0.30% Triethyl amine buffer (TEA) at pH = 4.5, adjusted using ortho-phosphoric acid); the mobile phase B (consisting of acetonitrile) was pumped through the column whose temperature was maintained at 40 °C, with a flow rate 1.7 mL/min, using gradient elution from 0-3 min A:B (75:25, v:v), then from 3-6 min the ratio changed to be A:B (60:40, v:v). Fluorescence detection (FLD) was performed at 410 nm after excitation at 239 nm. Acceptable linearity, accuracy and precision values of the proposed method were found over the concentration ranges of 0.5-15 µg/mL for LNG and 1.0-30 µg/mL for EMP with correlation coefficients of 0.9997 and 0.9998 in the case of LNG and EMP, respectively. The recoveries and relative standard deviations percentages were found in the following ranges: 98.56-101.85 and 0.53-1.52% for LNG and 98.00-101.95 and 0.31-1.05% for EMP. The detection and quantification limits were 0.15 and 0.45 µg/mL for LNG and 0.22 and 0.67 µg/mL for EMP. The optimized method was validated and proved to be specific, robust, accurate and reliable for the determination of the drugs in pure form or in their combined pharmaceutical preparations. No significant difference was found regarding accuracy and precision upon statistical comparison between the obtained results of the proposed method and those of the reported method. Furthermore, the proposed method is proved to be a stability-indicating assay after exposure of the studied drugs to variable forced degradation parameters, such as acidic, alkaline and oxidative conditions, according to the recommendations of the International Conference on Harmonization guidelines. The simplicity and selectivity of the proposed method allows its use in quality control laboratories.

Eco-Friendly Method for Determination of Allopurinol Drug in pure form and Pharmaceuticals After Cloud Point Extraction11

A new spectrophotometric method for the determination of allopurinol drug was investigated. The proposed method was based on the determination of allopurinol in pharmaceuticals. The method relies on the interaction of metal ions with allopurinol in an alkaline medium to form a micelles extracted from a non-ionic surfactant (Triton X-114) and allopurinol-Ag II at a maximum of 906 nm. Experimental variables were performed individually to obtain high extraction efficiency for both compounds. Under optimal conditions, Beer’s law was obeyed in the concentration range of 5-35 μg ml-1 ( r=0.9997) the detection limits of 0.245951 μgml-1 The proposed method was applied successfully for the determination of allopurinol drug in pharmaceuticals with a good accuracy and precision. The optimum condition for the colour development has also been investigated.

Chemometry‐assisted UV‐spectrophotmetric methods for the simultaneous determination of paritaprevir, ritonavir, and ombitasvir in their combined tablet dosage forms: A comparative study

AbstractThe ternary mixture under study is a recent hepatitis‐C antiviral medicine composed of three new directly acting antiviral drugs, namely, ombitasvir, paritaprevir, and ritonavir. They are co‐formulated as a single‐dose combined tablet dosage form. With more than 170 million infected patients worldwide, a large production scales of antivirals medicine is expected, and hence, new simple and fast methodologies are required to cover millions of analyses that are done routinely in the different pharmaceutical quality control and research laboratories. Ultraviolet spectrophotometry represents sensitive, fast, and cheap tool of analysis in all research and quality control laboratories that can cover the massive quality control of these regimens. However, the simultaneous determination of these three drugs using multivariate chemometric methods represents a high challenge as their spectra are strongly overlapping besides the large difference in their potency within the same tablet. In this research paper, four new different multivariate chemometric methods were developed for their simultaneous determination, namely, classical least square (CLS), principal component regression (PCR), partial least squares (PLS), and genetic algorithm‐partial least squares (GA‐PLS) techniques. The validated methods do not require extraction, separation, or derivatization steps. A comparative study was conducted among the four developed methods. All methods provided satisfactory results, whereas GA‐PLS showed better analytical performance as it had the lowest error with good higher correlation coefficient. The methods were applied in the simultaneous determination of the three drugs in pure form and in their combined tablet dosage form. The comparison confirmed agreement of the values obtained for all techniques.

Diode Array Detection for UPLC Determination of Cinnarizine and Dimenhydrinate in their Combined Dosage Form

Background: Cinnarizine is used to treat nausea and vomiting accompanied by motion sickness. Dimenhydrinate is used in the treatment of nausea and vomiting and dizziness. The coformulation of the two drugs showed the lowest rate of adverse effects compared to single dimenhydrinate. Objective: A fully validated ultra-performance liquid chromatographic method has been conducted for the simultaneous estimation of cinnarizine (CIN) and dimenhydrinate (DIM). Materials and Methods: The UPLC method used Acquity Column as stationary phase and mobile phase methanol: buffer (pH = 3.5 ± 0.05) and acetonitrile in the ratio of 50: 25: 25 at a flow rate of 0.2 mL/min. Detection was performed by DAD at 260 nm. Results and Discussion: Retention time was 0.71 and 1.12 min for DIM and CIN, respectively. The linearity was found to be 1-40 μg/mL and 2-80 μg/mL for CIN and DIM; respectively. Conclusion: The method was appropriately used for the quantitation of both drugs in pure form, synthetic mixtures and tablet preparation.

A Glassy Carbon Electrode for the Determination of Linagliptin, an Antidiabetic Drug in Pure Form, Tablets and Some Biological Fluids by Adsorptive Stripping Voltammetry.

The present work provides a fast, simple, accurate, and inexpensive analytical method for the determination of Linagliptin (anti-diabetic drug). The analysis was performed using a square wave adsorptive anodic stripping voltammetric technique (SWAASV) and glassy carbon electrode (GCE) as a working electrode. The experimental and instrumental parameters were studied and discussed to ensure the validity of the method. The method has a very good linearity (R2 = 0.9984), wide concentration range (0.189 - 2.268 μg mL-1), low detection limit of 0.052 μg mL-1 and low quantitation limit of 0.172 μg mL-1. Linagliptin was identified successfully using the proposed method in pharmaceutical formulations, spiked human urine and plasma with 99.67, 91.96, and 92.78% recovery, respectively, and the results obtained were compared with other reported methods.

Conductometric determination of trospium chloride by silver nitrate and phosphomolybidic acid

Two simple, accurate, sensitive and precise conductometric methods were developed for determination of trospium chloride in pure form and in pharmaceutical formulations. It is based on using two precipitating reagents; Phosphomolybdic acid (PMA) and Silver nitrate (AgNO3). The mean recovery for Silver nitrate is in the range (98-100.95%) and for Phosphomolybdic acid in the range (98-101.69%). A molar ratio has been determined conductometrically for the two reagents, revealed (1/1) for (drug/reagent). The proposed methods were validated and successfully applied for the determination of the studied drug in pure form and in its pharmaceutical preparation. The results of the proposed methods were compared to the results of reported method with no significant difference between them.

Investigation of micellar enhancement in simultaneous assay of rosuvastatin and amlodipine in their fixed-dose combined tablets

The native fluorescence of both rosuvastatin and amlodipine was investigated to carry out a new facile method for their simultaneous determination based on synchronous fluorimetric technique. It was found that addition of Tween-80 in a concentration above its critical micelle concentration causes significant increase in the sensitivity of the measurements for the two studied drugs. The developed method measured the first derivative synchronous amplitude (1D) for rosuvastatin at the zero-crossing point of amlodipine and vice versa over the linear ranges of (1.0–10.0 µg/mL) and (0.2–5.0 µg/mL) for rosuvastatin and amlodipine, respectively. All the validation criteria were assessed according to ICH guidelines. The method was further continued to the determination of the two drugs in pure forms, synthetic mixtures, single and combined Tablets with good percentage recoveries that ranged from about (98.0–102.0%). A comparison between the results of the suggested spectrofluorimetric method and previous reports for determination of each of the studied analytes has been carried out and statistical analysis revealed good agreement.

Chromatographic Methods for the Determination of Aminexil, Pyridoxine, and Niacinamide in a Novel Cosmetic Hair Preparation.

Aminexil, a new compound patented by L'Oreal, has a stimulating effect on human keratin fibers. Pyridoxine HCl and niacinamide are added to boost the hair tonic effect of aminexil. Two novel chromatographic methods were developed for the determination of aminexil (AX), niacinamide (NA) and pyridoxine HCl (PD) in the novel hair tonic preparation. The developed methods were high-performance liquid chromatography (HPLC) and thin layer chromatography (TLC) with densitometric determination. Different experimental parameters were investigated and optimized to achieve complete baseline separation and well resolved peaks. The RP-HPLC separation was achieved using a Thermoscientific BDS hypersil C18 (250 × 4.6 mm, 5 µm) column using 0.005 M hexane sulfonic acid: methanol (80: 20, v/v) as a mobile phase. For the TLC method, the three analytes were partitioned between propanol: toluene: ammonia solution (40:60:2, v/v/v) and fluorescent silica plates. The two methods were validated in compliance with International Conference on Harmonization (ICH) guidelines. The obtained data were statistically analyzed to confirm the existing results. The developed methods were successfully applied for determination of the studied drugs in pure forms and in the cosmetic preparation. For the HPLC method, the RSDs of AX, NA and PD were 0.70, 0.88 and 1.17 respectively. For the TLC method, the RSDs of AX, NA and PD were 1.06, 1.37 and 0.73 respectively. The proposed chromatographic methods showed high sensitivity and selectivity for the three compounds under analysis in the laboratory prepared mixture and in the hair tonic preparation. Aminexil, Pyridoxine, Niacinamide, HPLC. The present work offers two reproducible, accurate, validated, time and cost saving alternatives for the quantitative and qualitative determination of medicated hair preparation.

Spectrophotometric Determination of Clonazepam Drug in Pure form and Pharmaceutical Preparation by Diazotization Reaction

Spectrophotometric Determination of Clonazepam Drug in Pure form and Pharmaceutical Preparation by Diazotization Reaction

Micellar high performance liquid chromatographic method for separation and validation of two anti-hepatitis C- virus drugs in pure form, human plasma and human urine

In the present study, an eco- friendly micellar liquid chromatographic technique was validated for separation and quantification of two drugs; namely ribavirin (RIV), and sofosbuvir (SBV) in pure form, pharmaceuticals containing them, human plasma and human urine. These drugs are administered co-administered for treatment of Hepatitis C virus (HCV) that causes hepatitis C in humans. These drugs were separated using Nucleosil 100-5 phenyl column. Sodium dodecyl sulphate (SDS) solution (0.05M, pH 7.0) containing triethylamine (0.3%) and n-butanol (10%) was used as a mobile phase with 1.2 mLmin-1 flow rate and 215nm detection wavelength. Nine minutes were required for resolving the two drugs from the matrix. The method showed good linearity for RIV and SBV with correlation coefficients (r2) more than 0.9996 within the concentration ranges of (20-400) and (40-400) ngmL-1 in pure form, (30-300) and (50-300) ngmL-1 in human plasma and (20-400) and (40-400) ngmL-1 in human urine, respectively. The recommended method was applied for examination of RIV and SBV in pure and pharmaceuticals. The obtained results were statistically matched with reported methods with no significant differences. Also, the recommended method was effectively applied for estimation of both drugs in spiked human urine and plasma without purification or extraction steps and real samples of plasma and urine of humans having therapy of RIV and SBV, as well as, performing tablets dissolution-rate tests with satisfactory results.

Spectrophotometric Determination of some Drugs using Oxidation Reduction Reactions

A spectrophotometric method is proposed for the determination of some drugs containing amino group such as mesalazine, metoclopramide and dopamine in pharmaceutical formulations. It was simple, precise, accurate, rapid, and based on the oxidation of each drug with chromate as an oxidizing agent in the presence of 1N hydrochloric acid. Then indigo carmine is reacted with residual chromate in the presence of a catalysis factor (sodium oxalate). Increasing in absorbance's value of the color system is proportional to the amount of the three drugs which is measured at the selected wavelength of 610 nm.
 The proposed method is obeying Beer's law in the ranges of (1-40, 2-44 and 2-52) ppm for the concentration of mesalazine, metoclopramide and dopamine respectively. Molar absorptivity was 0.191×104, 0.449×104 and 0.191×104 L.mol-1.cm-1 mesalazine, metoclopramide and dopamine respectively. While, Sandell's sensitivity index of 0.0806, 0.0667 and 0.0806 μg.cm-2 mesalazine, metoclopramide and dopamine respectively.
 The proposed spectrophotometric method has a good recovery when it is applied for the determination of the three drugs in pure form and pharmaceutical doses.