Combined Pharmaceutical Dosage Form Research Articles

Spectral resolution techniques for the simultaneous spectrophotometric determination of anti-Parkinson drugs in their combined pharmaceutical dosage form and biological sample based on multivariate calibration and absorbance subtraction methods

In this study, simultaneous determination of levodopa (LEV) and carbidopa (CBD) in binary mixtures, pharmaceutical formulation, and biological sample was conducted using the application of simple, fast, sensitive, and accurate UV-spectrophotometry in combination with chemometrics methods. The first method is net analyte signal (NAS) based on the multivariate calibration methods. The limit of detection (LOD) and limit of quantification (LOQ) were 0.9758, 0.7633 µg/mL and 2.956, 2.313 µg/mL over the linear range of 5–40 and 0.5–20 µg/mL for LEV and CBD, respectively. In the NAS approach, the mean recovery values of mixtures were 100.12 % for LEV and 99.65 % for CBD, where root mean square error (RMSE) values were 0.0106 and 0.0141 for LEV and CBD, respectively. The second method is absorbance subtraction (AS) based on the absorption factor technique for analyzing the isosbestic point. This model was constructed at an isosbestic point of 261 nm in the range of 5–40 and 0.5–20 µg/mL with coefficient determination (R2) of 0.9985 and 0.9996 for LEV and CBD, respectively. AS method could estimate LEV and CBD with LOD values of 1.924 and 0.5657 μg/mL and LOQ values of 5.833 and 1.714 μg/mL, respectively. The recovery percentage was between 91.50 % to 104.60 % with RMSE of 0.1455 for LEV and 92.00 % to 106.66 % with RMSE of 0.2508 for CBD. The introduced approaches have the benefit of concurrent analysis of the mentioned components without any pretreatment. Statistical comparison of the results of real sample analysis with high-performance liquid chromatography (HPLC) did not show a significant difference. These methods can replace HPLC in quality control laboratories when fast, precise, and low-cost analysis is needed.

Analytical Method Developement and Validation of Beclomethasone, Clotrimazole, Ofloxacin, Lidocaine by RP-HPLC in Combination Dosage Form

A rapid and precise method (in accordance with ICH guidelines) is required for the quantitative simultaneous determination of drugs in a combined pharmaceutical dosage form. The pursuit of desired quality is a continual challenge for pharmaceutical industries, necessitating a meticulous approach known as validation. Sensitive and specific RP-HPLC method involving UV detection was carried for determination and quantification of various drug in combination dosage form. The aim is "Analytical Method developement and Validation of Beclomethasone, Clotrimazole, Ofloxacin, Lidocaine by RP- HPLC In Combination Dosage Form " as per ICH guidelines. The developed method was validated for various parameters as per ICH guidelines like system suitability, specificity, linearity, system precision, method precision, accuracy, ruggedness and robustness. The separation method was carried out by using a mobile phase A consisting of Potassium dihydrogen phosphate buffer (0.05M): Methanol 45:55 v/v) pH 3.5 ± 0.1 and Mobile phase B comprises Acetonitrile in the ratio of 50:50 v/v. The detection was carried out by using UV detector at 300nm. The column was Agilent C 18 (250X4.6mm) 5µ. The flow rate was selected as 1.5 ml/min. The retention time of Ofloxacin, Lidocaine, Beclomethasone, and Clotrimazole, was found to be 5.67, 9.44, 18.29, and 21.85 respectively.

Development and validation of a green spectrophotometric method for simultaneous determination of combined pharmaceutical dosage form (paracetamol and caffeine) using chemometrics technique in comparison with HPLC

Development and validation of a green spectrophotometric method for simultaneous determination of combined pharmaceutical dosage form (paracetamol and caffeine) using chemometrics technique in comparison with HPLC

A sustainable HPLC method coupled with diode array detection for versatile quantification of telmisartan, chlorthalidone and amlodipine in a fixed-dose antihypertensive formulation and dissolution studies

Cardiovascular diseases, especially hypertension, stand as prominent contributors to global mortality. Hypertension, often referred to as a silent killer syndrome, necessitates the use of multiple medications for effective control and management. A new environmentally friendly HPLC–DAD method is introduced in this study for the concurrent analysis of telmisartan (TEL), chlorthalidone (CHT) and amlodipine besylate (AML), in both pure forms and combined pharmaceutical dosage form. An isocratic elution mode was employed to achieve chromatographic separation, utilizing an Inertsil C18 column (250 × 4.6 mm, 5.0 µm) and a mobile phase mixture of acetonitrile and phosphate buffer (pH 3.0 ± 0.1) with ratio of 35:65, v/v. The separation was achieved within 10 min at a flow rate of 1.0 mL/min. The proposed method's validation was carried out following the guidelines outlined by the International Council for Harmonisation (ICH). The achieved linearity range was 1.0–140.0 μg/mL for TEL and 1.0–100.0 μg/mL for CHT and AML with quantification limits of 0.061, 0.177, and 0.313 μg/mL for TEL, CHT, and AML, respectively. The fixed combination tablet dosage form demonstrated acceptable release profile, as indicated by the in-vitro dissolution studies. The studied dissolution media were phosphate buffer pH 7.5, 0.01 N HCl, and water, utilizing a USP type II apparatus at 37 ± 0.5 °C with a stirring rate of 75 rpm. The proposed method was applied successfully for the quality assessment of Telma-ACT® Tablets with good precision and accuracy. Various tools were used for evaluating the level of greenness, including Green Analytical Procedure Index (GAPI), Analytical Greenness Metric for Sample Preparation (AGREEprep), Analytical Eco-Scale (AES), and Analytical Method Greenness Score (AMGS). These tools had confirmed the eco-friendliness of the proposed method. Additionally, the newly introduced White Analytical Chemistry (WAC), and the Blue Applicability Grade Index (BAGI) have been specifically developed to evaluate the sustainability and the applicability of the method.

A new RP-HPLC method for the simultaneous detection and quantification of minocycline and ascorbic acid in pure forms and combined pharmaceutical dosage forms

We report the first reverse-phase, high performance liquid chromatography (RP-HPLC) method for the rapid and simple simultaneous detection and quantification of minocycline and ascorbic acid in raw and pharmaceutical dosage forms. Detection was performed on a Sunniest C-18 column (5 μm particle size, 150 mm × 4.6 m mi.d(, at UV wavelength of 255 nm. The mobile phase consisted of potassium dihydrogen phosphate pH 2.8: Acetonitrile: Methanol (85:10:5), with 0.6 v/v% TEA and adjusted with orthophosphoric acid to a pH of 2.8 in an isocratic elution mode, with a flow rate of 0.8 mL/min. Performed analysis on the method proved that the newly developed method was sensitive, selective, accurate, precise, and robust. The method demonstrated good linearity with r2 = 0.9999 (n = 7) for both drugs and was validated in the sample concentration ranges of 1–100 and 5–500 µg mL−1 for minocycline and ascorbic acid, respectively. Both intra- and inter-day precisions were less than 2 % for both drugs, with limits of detection of 1.59 and 7.89 µg/mL and limits of quantification of 4.83 and 23.89 µg/mL, for minocycline and ascorbic acid, respectively. The applicability of the method was demonstrated by accurately determining the drug content of two commercial pharmaceutical formulations.

ChlorTox scale assessment, greenness, and whiteness evaluation of selective spectrophotometric analysis of dimenhydrinate and cinnarizine

Nausea and vomiting are considered common series side effects induced by chemotherapy treatment in cancer patients. This annoying side effect can impair the patient’s compliance to cancer treatment and affect their quality of life. Dimenhydrinate and cinnarizine in combined pharmaceutical dosage form is used to control chemotherapy induced nausea and vomiting in cancer patients. For safety, selective spectrophotometric methods based on novel dual resolution strategies were introduced to estimate dimenhydrinate and cinnarizine in presence of their harmful impurities namely benzophenone and 1- (diphenylmethyl)piperazine, respectively. These methods namely, dual ratio difference (DRD), dual ratio extraction (DRE) and dual absorbance extraction coupled with dual ratio extraction (DAE-DRE) were successfully performed to simultaneously analyze the drug of interests dimenhydrinate and cinnarizine in their pure form, synthetic mixtures and in market dosage form. Linearity ranges were 6.0–60.0 μg/mL and 3.0–30.0 μg/mL for dimenhydrinate and cinnarizine, respectively with good recovery% of Mean ± SD for all the proposed methods 99.82 ± 0.48, 99.79 ± 0.40, 100.14 ± 0.82, 100.03 ± 0.69, respectively. ICH guidelines were adhered in accordance with confirming validation of the proposed methods where fulfilling results were accomplished. Various unified greenness and whiteness assessment tools, such as the chlorTox scale, greenness index via spider chart, AGREE (The Analytical Greenness Metric), green certificate, and the RGB12 algorithm were employed in this research to assess the greenness and sustainability of the introduced UV-spectrophotometric methods in comparison to the reported HPLC method. As a result, these methods hold significant potential for utilization in the quality control department of pharmaceutical companies, contributing to enhanced pharmaceutical product analysis and overall sustainability practices.

Determination of levofloxacin, norfloxacin, and moxifloxacin in pharmaceutical dosage form or individually using derivative UV spectrophotometry

PurposeIn this study, first, second, third, and fourth-order derivative spectrophotometric methods utilizing the peak—zero (P—O) and peak-peak (P—P) techniques of measurement were developed for the determination of levofloxacin, norfloxacin, and moxifloxacin. These methods were applied to their combined pharmaceutical dosage form or individually for levofloxacin, norfloxacin, and moxifloxacin.MethodsLinearity was established in the concentration range of 2–20 µg/mL. The procedures are simple, quick, and precise. The developed methods are sensitive, accurate, and cost-effective, demonstrating excellent correlation coefficients (R2 = 0.9998) and mean recovery values ranging from 99.20% to 100.08%, indicating a high level of precision.ResultsThe developed approach was effectively employed to determine the levofloxacin, norfloxacin, and moxifloxacin content in commercially available pharmaceutical dosages.ConclusionsStatistical analysis and recovery tests confirmed the method's linearity and accuracy. The results suggest that this method can be utilized for routine analysis in both bulk and commercial formulations. The simplicity, accuracy, and cost-effectiveness of the developed methods make them valuable for pharmaceutical analysis.

Fast and efficient related substance determination of Rilpivirine and Dolutegravir in combined HIV therapy with RP-HPLC

The abstract discusses the development and validation of a Related Substance RP-HPLC method for the simultaneous estimation of Rilpivirine and Dolutegravir in a combined pharmaceutical dosage form, following their FDA approval for HIV treatment. The developed method utilized a simple and economical approach, employing an LC-20 AT C18 column with a Water:Methanol (70:30) mobile phase at a flow rate of 1 ml/min, and detection at 258 nm. Retention times for Rilpivirine and Dolutegravir were determined to be 3.82 min and 7.51 min, respectively, while Rilpivirine and Dolutegravir impurity retention times were found to be 4.32 min and 7.12 min, respectively. The method demonstrated excellent linearity for Rilpivirine impurity (5.0-15.0 μg/ml) and Dolutegravir impurity (7.5-22.5 μg/ml). Limits of detection (LOD) were 0.079μg/ml and 0.145μg/ml for Rilpivirine and Dolutegravir impurities, while limits of quantification (LOQ) were 0.241μg/mL and 0.441μg/mL, respectively. The proposed method was successfully applied for the simultaneous estimation of both drugs and their related impurities in a commercial combined dosage form.

A Validated RP-HPLC Method for Simultaneous Quantification of Abacavir and Zidovudine and their Impurities in Combined Dosage Forms

Develop a simple, accurate, and precise method for simultaneous analysis of Abacavir and Zidovudine, along with their related impurities, in combined pharmaceutical dosage forms. A reverse- phase high-performance liquid chromatography (RP-HPLC) method was developed using an LC-20 AT C18 column and a Water: Methanol (80:20) mobile phase. Detection was carried out at 240 nm. The method successfully separated Abacavir, Zidovudine, and their respective impurities with distinct retention times. Validation demonstrated good linearity, accuracy, and precision for both drugs and their impurities. Limits of detection (LOD) and quantification (LOQ) were determined and found to be suitable for analyzing impurities in commercial dosage forms. The developed RP-HPLC method offers a simple, accurate, and reliable tool for simultaneous quantification of Abacavir, Zidovudine, and their impurities in combined dosage forms, thereby contributing to quality control and ensuring drug safety. Keywords Abacavir, Zidovudine, Related Substance RP-HPLC Method, ICH Q2 (R1) guidelines

A modern chromatographic energy-saving approach for the analysis of doxycycline, ambroxol, and its precursor and impurity: Green metric assessment and comparison

The ternary mixture of doxycycline hyclate (DOX), ambroxol hydrochloride (AMB), and ambroxol synthetic precursor and process impurity (IMP) as chemically identified in the British Pharmacopeia as 2-amino-3, 5-dibromobenzaldehyde was examined for the first time using an ultra-performance liquid chromatographic technique. The presented work aimed to develop and validate a green accurate sensitive modern method for determination of this mixture. The obtained UPLC was accomplished by using an UPLC C18 column with mobile phase combination of acetonitrile: water (60:40, v/v) which was flowed at the rate of 0.22 mL per minute. Elution was in an isocratic manner and temperature control set at room temperature. UV was used to identify the effluent, which was injected at a volume of 5.00 µL; 370 nm for DOX and 240 nm for AMB and IMP. In concentration ranges; of (5–150) µg mL−1, linearity of both DOX and AMB was attained and of (0.5–40) µg mL−1, linearity of IMP was attained. Accuracy of this UPLC method was found to be 100.28, 99.66, and 100.36 for DOX, AMB, and IMP, respectively. ICH standards were followed while making the method validation. The existing combined pharmaceutical dosage form was analyzed by the obtained UPLC method for determination of the evaluated drugs successfully and the obtained results expressed as (Recovery % ± SD) were 101.02 ± 1.37 for DOX and 102.22 ± 1.56 for AMB. Also, the statistically significant correlation of our created approach to the reported HPLC method revealed no appreciable differences in terms of accuracy and precision. The developed method’s greenness profile was appraised using many greenness metrics, green assessment comparison between the established columnar method and the published ones was made.

Green electrochemical methodology for simultaneous determination of atorvastatin and ezetimibe: Application to biological matrices

In this context, we report the first electrochemical sensing platform for the simultaneous quantitation of two antihyperlipidemic drugs, namely, atorvastatin (ATR) and ezetimibe (EZT), fabricated of manganese oxide nanoparticles/multi-walled carbon nanotubes/modified carbon paste electrodes (Mn2O3/MWCNT/MCPE). The developed composite was characterized physicochemical and electrochemically and the experimental conditions were optimized. Using square wave voltammetry (SWV), two wide linear dynamic ranges were attained for both drugs: 1.0–100 × 10−8 M and 2.0–100 × 10−6 M. The calculated detection and quantitation limits were 3.97 × 10−9 and 12.03 × 10−9 M for ATR and 4.66 × 10−9 and 14.12 × 10−9 M for EZT, respectively. The suggested platform was successfully applied for the simultaneous analysis of both drugs in human urine and plasma samples, in addition to a combined pharmaceutical dosage form (ATOZET® film coated tablets) and satisfactory percentage recoveries were obtained using Eco-scale and AGREE greenness tools for evaluating the greenness of analytical methodology.Furthermore, repeatability, stability testing, interferences study and greenness assessment were conducted and confirmed the reliability of the suggested platform for the simultaneous determination of both drugs in quality control laboratories.

Simultaneous Determination of Estradiol Cypionate and Medroxyprogesterone Acetate Hormones in Injectable Suspension by UV Spectrophotometry Based on Least-Squares Support Vector Machine and Fuzzy Inference System: Comparison with HPLC.

The combination of estradiol cypionate (ECA) and medroxyprogesterone acetate (MPA) is used to prevent pregnancy in women. The analysis of the ECA and MPA combination reveals a challenge due to the strong overlap of the spectra of these compounds. Spectrophotometry techniques along with chemometrics methods are simple, fast, precise, and low-cost for the simultaneous determination of ECA and MPA in a combined pharmaceutical dosage form. Two developed approaches, the least-squares support vector machine (LSSVM) and fuzzy inference system (FIS), along with a spectrophotometric method were proposed to solve such a challenging overlap. Based on the cross-validation method, the regularization parameter (γ) and width of the function (σ) in the LSSVM model were optimized and the root mean square error (RMSE) values were found to be 0.3957 and 0.2839 for ECA and MDA, respectively. The mean recovery values were 99.87 and 99.63% for ECA and MDA, respectively. The FIS coupled with principal component analysis (PCA) showed mean recovery percentages equal to 99.05 and 99.50% for ECA and MDA, respectively. Also, the RMSE of both components was lower than 0.3. The analysis results of a real sample (injection suspension) using the proposed methods were compared with HPLC by a one-way analysis of variance (ANOVA) test, and no significant differences were found in the results. Intelligent methods were proposed for the simultaneous determination of ECA and MPA. The least-squares support vector machine and fuzzy inference system along with spectrophotometry were used. HPLC as a reference method was performed and compared with chemometrics methods. The benefits of the proposed approaches are that they are rapid, simple, low-cost, and accurate.

Development and validation of stability indicating thin‐layer chromatography method for simultaneous estimation of Benidipine hydrochloride and Telmisartan

AbstractFor the simultaneous estimation of Benidipine hydrochloride (BEN) and Telmisartan (TEL) in combined pharmaceutical dosage form, a stability‐indicating high‐performance thin‐layer chromatography (HPTLC) method has been developed and validated. It involves the use of HPTLC plates pre‐coated with silica gel 60F254 and a mobile phase comprising of Methanol: Acetonitrile (1:9 v/v). The measurements of both drugs were performed at 237 nm. The drugs were subjected to acid‐alkali hydrolysis, photolytic, thermal, and oxidation degradation. The linearity of BEN was found to be between 200–1000 ng/band (R2 = 0.9917), while for TEL, linearity was found to be between 2000 and 10000 ng/band (R2 = 0.9979). The limit of detection and limit of quantitation were found to be 3.28 and 9.94 ng/spot for BEN and 158.79 and 481.17 ng/spot for TEL. The % relative standard deviation of the precision study was determined to be less than 2%. Various system suitability parameters were determined. The Rf values of BEN and TEL were found to be 0.890 ± 0.0105 and 0.173 ± 0.0151, respectively. The resolution between BEN and TEL peak were found to be 4.48 and capacity factors were found to be 0.21 and 0.74 for BEN and TEL, respectively.

Mathematical processing of absorption as green smart spectrophotometric methods for concurrent assay of hepatitis C antiviral drugs, Sofosbuvir and Simeprevir: application to combined pharmaceutical dosage forms and evaluation of the method greenness

The present work was developed to create three rapid, simple, eco-friendly, cheap spectrophotometric methods for concurrent assay of Sofosbuvir (SOF) and Simeprevir (SMV) in their pure, laboratory prepared mixture and pharmaceutical dosage form with high degree of accuracy and precision. Three methods were developed including iso-absorptive point, ratio subtraction and dual wavelength. The linear range of the proposed methods was 3.0–50.0 and 2.0–50.0 µg mL−1 for SMV and SOF, respectively. The proposed methods were validated according to ICH guidelines in terms of linearity, accuracy, precision, limit of detection and limit of quantitation. The proposed approach is highly simple and the procedure is environmentally green making it suitable for the drug analysis in routine works.

New analytical LC–MS/MS method for fluconazole and ivermectin estimation in combined pharmaceutical dosage form: development and validation

BackgroundFluconazole, an antifungal drug, prevents fungi growth by inhibiting the formation of a protective covering. Ivermectin has several biological activities, such as antibacterial, antiviral, and anti-cancer characteristics, and offers various therapeutic outcomes. There are several commercial products containing these two drugs. Therefore, developing a method that can allow the simultaneous estimation of Fluconazole and ivermectin is inevitable to monitor them in commercial dosage forms. The hyphenated methodology that combines spectroscopic and chromatographic techniques is gaining high interest in the pharmaceutical industry. Consequently, the objective of present research work was to investigate robust and sensitive LC–MS/MS avenue for simultaneous determination of Fluconazole and ivermectin in pure material and combined dosage form.ResultsThe simultaneous quantification of Fluconazole and ivermectin in tablet dosage form has been developed and validated using a straightforward, sensitive, practical, and repeatable LC–MS/MS approach. The separation was performed using a C18 (150 × 4.6 mm) column, injection volume of 10 µL, and elution with acetonitrile: formic acid at a ratio of 70:30, with the column temperature at 30 °C, and a flow rate of 4.0 mL/min. The retention times of Ivermectin and Fluconazole were 1.10 min and 1.05 min, respectively. The calibration curves for Fluconazole and ivermectin demonstrated significant linearities indicated by the correlation coefficients (r2 = 0.999 and r2 = 0.997) and precision (% R.S.D. of 1.58 and 1.13). The linear correlation between peak area and concentration allowed high percentage recoveries of 98.5%–99.4% and 97.8%–99.3% for Fluconazole and Ivermectin, respectively. The L.O.D.s for Fluconazole and ivermectin were found to be 0.0034 and 0.074 g/mL, respectively. The L.O.Q.s for Fluconazole and ivermectin were 0.010 and 0.225 g/mL, respectively.ConclusionAll the analytical parameters were identified and found to be within the acceptable range set forth by the ICH guidelines, demonstrating the devised method's acceptability in the simultaneous detection and estimation of Fluconazole and ivermectin in the commercial dosage forms.

UV SPECTROSCOPIC METHOD DEVELOPMENT AND VALIDATION OF FIRST DERIVATIVE METHOD FOR SIMULTANEOUS ESTIMATION OF PRAZIQUANTEL AND ABAMECTIN IN FINISHED DOSAGE FORM

In the present investigation, methanol is employed as the solubilizing agent to solubilize poorly water soluble drugs such as praziquantel and abamectin. UV spectrophotometric method has been developed for simultaneous estimation of praziquantel and abamectin in bulk drug and in their combined pharmaceutical dosage form by first order derivative method. This method utilizes methanol as a common solvent and λmax of praziquantel and abamectin selected for analysis was found to be at 248 nm (at ZCP of abamectin) and 274 nm (at ZCP of praziquantel), respectively. Linearity was observed in the concentration range of 25-150 µg mL-1 for praziquantel (r2 = 0.9984) and 1-11 µg mL-1 for ABAM (r2 = 0.9986). The accuracy and precision were determined and found to comply with ICH guidelines. This method shows good reproducibility and recovery with % RSD in the desired range. Developed method was applied for marketed formulation. The results were found to be within acceptance criteria according to ICH guideline

Development and Validation of Stability‐Indicating HPLC Method for Simultaneous Quantification of Vardenafil and Dapoxetine in Bulk and in Combined Dosage Form

AbstractAn understanding of drug product degradation issues is needed to advise stable formulation and provide a reasonable shelf‐life evaluation for all drug products. For this purpose, we have developed and validated a novel HPLC method for assessing the stability of vardenafil and dapoxetine in a combined pharmaceutical dosage form. The chromatographic separation was accomplished on a ProntoSIL C18 KROMA PLUS column (250×4.6 mm, 5 μm). The column was run under isocratic conditions with a 2.0 mL/min flow rate. The mobile phase was made up of methanol and 20 mM potassium dihydrogen phosphate at 45 : 55 (v/v), which was adjusted to pH 3.0 with phosphoric acid; these two drugs were eluted at retention times of 5.33 and 9.91 min for vardenafil and dapoxetine, respectively. The proposed method shows a linearity of 1–50 ug/ml with a regression of 0.9999 for both drugs. The method was validated for accuracy, precision, linearity, specificity, and sensitivity. The developed HPLC method has been successfully implemented to analyse dapoxetine and vardenafil in tablets. Furthermore, the stress degradation experiments were conducted on the bulk powder of vardenafil and dapoxetine following the International Council for Harmonization (ICH) recommendations.

Construction of a Zinc Oxide Nanorod-Modified Coated Wire Electrode for Potentiometric Determination of Levocetirizine Dihydrochloride in Its Pure and Combined Form.

Coated wire electrodes (CWEs) are considered the most effective and selective type of ion- selective electrodes because of the electroactive materials which are used in surface modification. This study aims to construct the first potentiometric method for analysis of levocetirizine (LVZ) in its combination form with montelukast (MON) drug. A novel potentiometric sensor which consists of a silver wire coated with zinc oxide (ZnO) nanorod modified with a polymeric membrane (combining β-cyclodextrin and tetraphenyl borate, and plasticized with di-butyl phthalate) was constructed for the determination of LVZ·2HCl in its pure form and its combination dosage form. The fabricated sensor exhibited a linearity range of 5 × 10-6-1 × 10-2 mol/L with a Nernstian slope 57.88 mV/decade over the pH range 2-4.5. The effect of temperature on the constructed sensor was studied and it was found that the electrode worked effectively over 10-50°C. The electrode showed a fast response time and the lifetime of the electrode was found to be 72 days without significant change in the Nernstian slope value. The selectivity of the electrode toward LVZ was estimated in the presence of some obstructive ions. The method was validated according to International Council for Harmonisation of Technical Requirments for Registration of Pharmaceuticals for Human Use (ICH) rules and applied to the determination of LVZ in its pure and combined pharmaceutical dosage forms. This article introduces the synthesis of the first coated wire electrode modified with zinc oxide (ZnO) nanorods for the determination of the drug levocetirizine. The results demonstrate the ability of electrochemical methods to analyze drugs in combination. The presented method excels over the other analytical methods in terms of sensitivity, selectivity, and simplicity.

Stability Indicating HPLC Method for Simultaneous Assessment of Clopidogrel Bisulfate and Aspirin: Development and Validation

Objectives: The efforts were made to develop a HPLC analytical method for the simultaneous quantitative estimation of aspirin and clopidogrel and aim to identify and estimate the degradation of the drugs under the various stress conditions recommended by ICH guideline. Materials and Methods: The separation of two drugs were done by using LC-20AD liquid chromatograph having SPD-20A UV-vis detector on C18 (4.6 x 150 mm) column which was connected with loop 20μl and with HPLC-Dell system. Mobile phase consisted of acetonitrile: buffer in the ratio of 350:650 v/v. Flow rate was 1.3 ml/min and detection were done at 220 nm. Proportions of solvents and adjustment of mobile phase was carried out by screening. Results: The chromatographic separation of aspirin was noted at 4.299 minutes with average USP tangent of 8332.046 and clopidogrel was at 12.706 min with average of 11886.0397 tangent. A linear correlation was observed between concentration of aspirin and clopidogrel with their dilutions i.e r2 = 0.9986 and 0.9996 respectively. The outcome of study, with limit of detection 0.058 and 0.078 μg/ml and limit of quantification 0.117 and 0.156 μg/ml, for aspirin and clopidogrel revealed the repeatability, reproducibility and robustness of the method. Stability indicating parameters were tested by ICH guideline. Conclusion: It is concluded that the method is linear, reproducible, robust, rugged and stability-indicating for simultaneous calculation. It can be used as a routine quality control method for combined pharmaceutical dosage form and for its kinetic studies.

Rapid HPLC determination of ciprofloxacin, ofloxacin, and marbofloxacin alone or in a mixture

A simple, sensitive, and accurate chromatography (RP-HPLC) method for simultaneous estimation of Ciprofloxacin, Ofloxacin, and Marbofloxacin in their combined pharmaceutical dosage form or individually. The HPLC separation was achieved on a Hypersil (C18, 150 mm × 4.6 mm, 5 μm particle size) analytical column or equivalent. A mixture of triethanolamine (1 %), acetonitrile (80 %), and water was used as the mobile phase, with a flow rate of 1.2 mL /min and a detector wavelength of 280 nm at ambient temperature. In the HPLC method, the retention times of Ciprofloxacin, Ofloxacin, and Marbofloxacin were found to be 1.854, 2.480, and 4.688 min, respectively, and linearity was obtained in the range of 25–80 µg/mL for Ciprofloxacin, Ofloxacin, and Marbofloxacin. The correlation coefficient for the method was greater than 0.999. The RP-HPLC method validation parameter lay within its acceptance criteria as per the ICHq2 (R1) guideline. Hence, it can be successfully used for routine analysis of Ciprofloxacin, Ofloxacin, and Marbofloxacin in raw material or pharmaceutical dosage forms.