Spectrophotometric determination of meloxicam in medicinal products

Aim. To develop and validate a spectrophotometric technique for quantitative determination of glibenclamide in tablets by reaction with 2,3-dichloro-1,4-naphthoquinone. Materials and methods. In the study, the substance glibenclamide of pharmacopoeial purity was used, tablets – “Maninil” 5 mg and “Glibenclamid-Zdorovye” 5 mg, 2,3-dichloro-1,4-naphthoquinone of the “CFA” qualification was chosen as a reagent, as a solvent – dimethylformamide (DMF) “CFA”. The following analytical equipment was used for the research: spectrophotometer “Specord-200” (Analytic Jena AG, Germany), water bath “MEMMERT WNB7”, laboratory electronic scales RADWAG XA 210. 4Y, measuring laboratory vessels of class A. Results. A new, simple spectrophotometric method of quantitative determination of glibenclamide in tablets by reaction with 2,3-dichloro-1,4-naphthoquinone in DMF medium was developed. The absorption maximum was at 489–491 nm. The value of the detection limit is 10.9 μg/ml, which indicates sufficient sensitivity of the reaction. Subordination to the basic law of light absorption is within the limits of concentrations of 13.7–27.4 mg/100 ml. In the process of developing the methodology, the following validation characteristics were determined: specificity, linearity, precision, correctness, and robustness. Conclusions. The methodology for the quantitative determination of glibenclamide was developed and validated according to the requirements of the State Pharmacopoeia of Ukraine. It has been proven that the method is simple, accessible, and validated for such characteristics as linearity, convergence and robustness and can be used for application in laboratories for quality control of medicinal products.

Foot fungus (Candida, molds, dermatophytes) is a fairly common problem. According to the WHO, one-fifth of the world’s population is affected by fungal skin diseases. The prevalence of mycosis of the feet, which affects every second person, is especially increasing. Such a pathology can appear quite unexpectedly and at an inappropriate time. Today, Ukraine is under aggressive pressure from its northern neighbor, and military personnel are not only constantly at risk of receiving combat injuries and wounds, but also due to active hostilities, they may not have access to the necessary hygiene products, get cold, overheat in the sun, or not have time to change their clothes in time. and shoes. The reality is the absence or delay of treatment; the disease progresses and can spread quickly. If mycosis has appeared in one soldier, it can quickly affect others. Therefore, the problem of providing medical and pharmaceutical care is an urgent issue today. Expanding the assortment of drugs with the above action will ensure the needs of the Armed Forces and civilian patients with this dermatological pathology. It will be able to optimize antifungal therapy regimens. For quite a long time, 1,2,4-triazole derivatives have been a promising class of organic compounds that attract the attention of scientists from various fields. It has been proven that 2-(((3-(2-fluorophenyl)-5-thio-4H-1,2,4-triazole-4-yl)imino)methyl)phenol has high antifungal activity. A potential medicinal product based on this medicinal substance can be used for the treatment of various dermatological diseases. To continue the creation of new effective dosage forms for the effective therapy of mycosis of the feet, the urgent task of today is the development of an express, accurate, reliable, and affordable method of quantitative determination of the substance under study. The aim of the work is to develop an express, sensitive and easy-to-implement UV-method for the quantitative determination of 2-(((3-(2-fluorophenyl)-5-thio-4H-1,2,4-triazole-4-yl)imino)methyl)phenol. Materials and methods. The research object is a working standard sample of 2-(((3-(2-fluorophenyl)-5-thio-4H-1,2,4-triazole-4-yl)imino)methyl)phenol provided by NUNVF, LLC “Brovapharma” according to the “Research and production technological regulations for the production of 2-(((3-(2-fluorophenyl)-5-thio-4H-1,2,4-triazol-4-yl)imino)methyl)phenol” developed based on scientific developed by the Ukrainian Military Medical Academy in conjunction with the National Military Medical Clinical Center “Main Military Clinical Hospital” (term of validity of the regulations until 12/31/2034). Isopropanol of grade “chemically pure” was used as a solvent. Analytical equipment: spectrophotometer Specord 200, electronic scales Radwag XA 210.4Y, class A measuring vessels. Results. An express, eco-friendly spectrophotometric method was developed for the quantification of 2-(((3-(2-fluorophenyl)-5-thio-4H-1,2,4-triazole-4-yl)imino)methyl)phenol in isopropanol area, having analytically maximum at 310 nm. The studied solutions are stable for 30 minutes. The analytical technique is linear in the range of concentrations 0.440–0.754 mg/100 ml (70–130 %). The detection and quantification limits were 5.80 % and 15.70 % respectively. The score was 0.76, according to the “greenness” icon of the analytical technique, using the tools AGREE. The prediction of the total uncertainty of the results of the developed method is 1.70 % (max∆As 2.00 %). The proposed method is relevant according to the requirements of the State Pharmacopoeia of Ukraine. Conclusions. Pharmaceutical development, introduction into industrial production and further prescribing by dermatovenerologists of an effective, safe, and harmless medicinal product will help to expand the range and reduce the level of high import dependence of the domestic market of medicinal products, which will create a more complete and balanced system of medicinal supply in Ukraine and optimize antifungal therapy schemes.

A simple, accurate and sensitive spectrophotometric method for determination of bromhexine-HCl in aqueous solution has been described. The proposed method is based on the reduction of cerium (Іν) in acidic medium into cerium (Ш) by the drug followed by the complex formation of cerium (Ш) with arsenazo Ш to form a greenish-blue water soluble, stable complex that has a maximum absorbance at 651nm against the reagent blank. Beer’s law is obeyed in the range of 10 to 200μg of bromhexine-HCl /20 ml (i.e. 0.5-10 ppm) with molar absorptivity of 1.48×104 l.mol-1. cm-1 and a good determination coefficient (R2=0.9978). The limit of detection (LOD) and limit of quantification (LOQ) are 0.408 and 1.394μg ml−1, respectively. The relative error and a relative standard deviations are found in the range -0.354 to1.93 % and ± 0.135 to ± 1.033%, respectively, depending on the conc-entration level. The method is suitable for the determination of bromhexine-HCl in the presence of other ingredients that are usually present in dosage forms. This procedure is applied successfully for the analysis of bromhexine-HCl in pharmaceutical preparations (tablets, syrup and injection) without prior separation and with acceptable errors

Objective: The present work is aimed to develop a simple, rapid, selective and economical UV spectrophotometric method for quantitative determination of Glipizideinbulk and pharmaceutical dosage form.
 Methods: In this method Dimethyl Form amide (DMF) was used as solvent, the absorption maxima was found to be275 nm in DMF. The developed method was validated for linearity, accuracy, precision, ruggedness, robustness, LOD and LOQ in accordance with the requirements of ICH guideline.
 Results: The linearity was found to be 10-60 µg/ml having linear equation y=0.017x-0.006 with correlation coefficient of 0.997. The% recovery was found to be in the range of 98.7-100%. The % RSD for intra-day and inter-day precision was found to be 0.569923 and 0.40169 respectively. The limit of detection (LOD) and limit of quantification (LOQ) was found to be3.06 µg/ml and 9.27 µg/ml respectively.
 Conclusion: The developed method was validated as per ICH Q2(R1) guidelines. The novel method is applicable for the analysis of bulk drug in its pharmaceutical dosage form.

In Ukraine, there are about 100 thousand people with epilepsy. Gabapentin is an effective antiepileptic agent for oral use, presented in capsules of different dosages from different manufacturers. Therefore, the urgent task of pharmaceutical analysis today is the development of highly accurate, reliable, affordable and fast methods of quantitative determination. The aim of the work is to develop a spectrophotometric technique for the quantitative determination of gabapentin in capsules based on the reaction with diazole red 2J in compliance with the SPhU. Material and methods. As reagent and solvent, diazole red 2J of AR grade, acetone of AR grade and purified water was used. Analytical equipment: Specord 200 and Specord 250 Plus spectrophotometers, ABT-120-5DM and Radwag XA 210.4Y electronic scales, Elmasonic E 60H and Sonorex Digitec DT100H ultrasonic baths, measuring glassware of A class. Results. A simple, accurate and eco-friendly colourimetric method was developed for the quantification of gabapentin in capsules. The method was based on the reaction of gabapentin with diazole red 2J to give a coloured product having analytical maxima at 390 nm. Factors affecting colour development and stability were optimized and incorporated into the procedure. Regression analysis of Beer's plot showed a good correlation (not less than 0.999) in a concentration range of 2.10 – 3.64 mg/100 ml. The detection and quantification limits were 2.25 % and 6.19 %, respectively. The intra- and inter-laboratory precision demonstrates and reflects no interference by the capsule additives and confirms the reproducibility of the method in the selected concentration range. The prediction of the total uncertainty of the results of the developed method is calculated and displayed to assess the correctness of the reproduction of the method. Conclusions. It has been proven that the developed method meets the requirements of the State Pharmacopoeia of Ukraine and allows to perform the correct quality control of medicinal products.

A simple, sensitive, precise and accurate HPTLC method has been developed for the simultaneous estimation of the ciprofloxacin and ornidazole in tablets. The stationary phase used was precoated silica gel 60F 254 plate. The mobile phase used was a mixture of n-butanol:ethanol:8M ammonia (5:0.5:1.5, v/v/ v). The densitometric scanning was carried out at 315 nm. This system was found to give compact spots for ciprofloxacin (R f value of 0.25 0.004) and ornidazole (R f value of 0.82 ± 0.007). The method was validated in terms of linearity, accuracy, precision, limit of detection, limit of quantification and specificity in accordance with the ICH guidelines. The calibration curve was found to be linear between 40 to 140 ng/spot for each ciprofloxacin and ornidazole with significantly high value of correlation coefficient (r 2 > 0.99). The limit of detection and quantitation were found to be 10.01 and 33.03 ng/spot, respectively for ciprofloxacin and the limit of detection and quantification were found to be 7.62 and 25.15 ng/spot, respectively for ornidazole. The results of analysis have been validated statistically and by recovery studies. The proposed HPTLC method can be successfully applied in the routine analysis of commercial pharmaceutical tablets.

Objective: A new spectrophotometric method for the gliclazide quantitation in dosage forms has been developedMaterial and Method: The subjects of the study were modified-release tablets ("Diaglizide" 80 mg, "Diaglizide MR" 60 mg, "Diaglizide MR" 30 mg, "Diabeton" MR 60 mg, "Gliklada" 60 mg). As a reagent, bromocresol green in acetone was used. Analytical equipment: spectrophotometer Specord 200, electronic scales АВТ-120-5DM.Result and Discussion: It has been experimentally determined that gliclazide reacts with bromocresol green in acetone medium at room temperature to form a yellow product with maximum absorption at 411 nm. The method was validated for linearity, accuracy, precision, and robustness. The agent’s optimal concentration was established and the stability of the investigated solutions was checked by measuring their optical density for 30 minutes. Subordination of Beer's law is observed in the range of 62.00 - 94.00 mg/100 ml. The limit of detection is 4.02∙10-6 g/ml, which indicates a high sensitivity of the reaction. The proposed method is validated according to the requirements of the State Pharmacopoeia of Ukraine. The results of the study show that the developed method is simple and affordable to implement and can be used to determine gliclazide in drugs in laboratories for quality control of dosage forms.

A sensitive, reproducible isocratic reversed phase method has been developed and validated for the simultaneous quantification of enalapril and diuretics (hydrochlorothiazide and furosemide) in active pharmaceutical ingredients, dosage formulations and human serum using high-performance liquid chromatography (RP-HPLC). The method was validated according to ICH guidelines for the parameters: specificity, stability, limits of detection (LLOD), limits of quantification (LLOQ), linearity, accuracy, precision and recovery. Chromatographic separation was performed on Hypersil ODS C18 (150×4.6mm, 5micron) and Purospher Start C18 (250 mm×4.6 mm, 5 μm) columns using gradient elution, when methanol: water (75:25 v/v) was used as the mobile phase and pH adjusted to 3 with orthophosphoric acid having flow rate of 1.0 mL min-1 at ambient temperature. The lower limit of quantitation (LLOQ) and detection (LLOD) were 5,4.6,12.6 and 1.6,1.53,4.1 ngL-1 for HCT, ENP and FRS respectively. Calibration curves were linear in the concentration range of 2.5-100 μg mL-1 with a correlation coefficient ± 0.999 for all three drugs. Intra-day and inter-day precisions were less than 2 %. The accuracies were in the range of precision 98.0–102%. The retention time of HCT, ENP and FRS were found to be 3,3.5 and 4 mins respectively which shows the rapidness. This is the first full report of a method for the simultaneous determination of these three key drugs. The newly developed method is useful for future routine analysis of these drugs enalapril and diuretics in active pharmaceutical ingredients, pharmaceutical preparations, serum and could be used in therapeutic drug monitoring, clinical, laboratories and adherence to medicine studies, which would be helpful in decision making regarding treatment change in combination therapies.

Background and importancePharmaceutical compounding is an integral part of the services provided by pharmacies for the specific needs of patients. For these pharmaceutical preparations the requirements of the European Pharmacopoeia...

Aim. The research aims at developing a fast, simple, reliable spectrophotometric method according to "green" chemistry principles for the determination of lisinopril in pure substance and in drugs presented on the Ukrainian market. Materials and Methods. Chemical reference standard of lisinopril dihydrate (Sigma-Aldrich, ³98%, HPLC), methanol R (Honeywell Riedel-de Haen™, 99.9%), tablets of Lisinopril-Astrapharm 10 mg), Lisinopril-KRKA 10 mg (Slovenia) and Lisinopril-Teva 10 mg (Germany) were used in this study. Double-beam scanning spectrophotometer "Shimadzu UV-1800" (Japan) connected with software package UV-Probe 2.62 were used for measurements. Absorbance of the solutions in the UV region were recorded in 1 cm quartz cells vs. methanol R. Laboratory electronic balance RAD WAG AS 200 / C, ultrasonic bath Sonorex Digitec DT100H and measuring glassware of grade A were used. Statistical processing and determination of validation parameters were performed in accordance with the requirements of State Pharmacopoeia of Ukraine 2.0 and ICH Q2. Results and Discussions. The spectrophotometric method for the determination of lisinopril by direct measurement of the absorbance of the tested solutions in the ultraviolet region of the spectrum has been developed (lmax=212 nm). Validation parameters including linearity, range of application, specificity, accuracy, precision, limit of detection and limit of quantification, robustness were calculated for the proposed analytical procedure. The correctness of the analytical method was proved by calculating the complete uncertainty of the latter. The calculated uncertainty of sample preparation (DSP) for the determination of lisinopril in tablets was 2.46%. It was established that the maximum contribution to the uncertainty of sample preparation for operations of the quantification of lisinopril in tablets, make the operations of lisinopril CRS sampling and aliquots pipetting. The total uncertainty of the analytical procedure (DAs) in the analysis of the drug was 2.56%. The predicted complete uncertainty of the analysis results did not exceed critical values (DAs=2.56 % £ maxDAs=3.2 %), the method is correct. The specificity is proved by the absence of interfering influence of excipients due to nonoccurence of absorption at the analytical wavelength in the analysis of methanolic extract of placebo-tested tablets, Beers law was obeyed in the ranges of 20-100 mg / ml. The least squares method was used for statistical processing of the results. Regression analysis yielded the following calibration equation: y=26,791x-0,4398. The limit of detection and the limit of quantification were 2,3 і 6,9 mg/ml. Robustness of the method was estimated by studying of absorbance stability changes of tested solutions over time. Robustness was assessed by studying the absorbance stability of the tested solutions over time. It was found that freshly prepared solutions should be used within 100 min. Developed procedure for lisinopril determination in pure substance and tablet dosage form proved to be an excellent green analysis according to analytical eco-scale. Conclusions. Fast, simple, reliable, cost-effective, in accordance with the principles of "green" chemistry spectrophotometric method for determination of lisinopril in pure substance and tablets has been proposed. Validation of the analytical procedure on the parameters of linearity, application range, specificity, accuracy, precision, robustness, limit of detection and limit of quantification was carried out. The complete uncertainty of the analytical procedure at the level of 2.56% was obtained, which proves the possibility of obtaining correct analysis results in other laboratories.

The aim of the work was to develop a simple, rapid, economic spectrophotometric method for the determination of meldonium in capsules based on the reaction with alizarin. Materials and methods. Analytical equipment: double-beam UV-visible spectrophotometer Shimadzu UV 1800 (Japan), a pair of 1 cm matched quartz cells, software UV-Probe 2.62, laboratory electronic balance RAD WAG AS 200/C, pH-meter И-160МИ. Pharmacopoeial standard sample (CRS) of meldonium dihydrate (Sigma-Aldrich, (≥ 98 %, HPLC)), alizarin (Synbias), capsules Metamax (Darnytsia) 250 mg, Vasopro (Farmak) 500 mg, Mildronate (Grindex) 500 mg, dimethylformamide (“Honeywell Riedel-de Haen”). Results and discussion. A spectrophotometric method for determining meldonium in capsules by reaction with alizarine has been developed. The absorption maximum of the formed complex in dimethylformamide was at a wavelength of 517 nm. Stoichiometric ratios of reactive components «meldonium- alizarin» were 1:1. Validation of the developed analytical method for the determination of meldonium in medicines was carried out in accordance with the requirements of the SPhU. The optimal conditions for performing the quantitative determination of meldonium have been established: concentration of alizarin solution – 0.8 %, volume 0.8 % alizarin solution – 0.5 ml, heating time – 20 min, temperature – 95+/- 2 °C. Linearity has been in the concentration range of 0.0402- 0.1073 mg/mL, the limit of detection - 2.84 μg/mL, and the limit of quantification – 8.59 μg/mL. The eco-friendliness of the developed analytical method was carried out using the analytical eco-scale, AGREE, and GAPI methods. Conclusions. The developed method can be used as an arbitration method for the routine analysis of meldonium capsules

Opening the Black Box of Biomarker Measurement Error

Objectives: In this work, a new, rapid, simple, precise and specific method has been developed for the simultaneous determination of amlodipine (AML) and rosuvastatin (ROS) in pharmaceutical preparations by square wave voltammetry (SWV). Methods: Electrochemical behavior and simultaneous voltammetric determination of AML and ROS were investigated using platinum disk electrode. Validation parameters such as specificity, linearity, accuracy, precision, ruggedness, stability, limit of quantification and limit of detection were studied according to the ICH Guidelines. Results: The linearity of this developed method was established in the concentration range of 5-40 μg/mL for AML and ROS, respectively. The precision was less than 1.88 and 1.93%, determined from quality control samples for AML and ROS, and accuracy was within 1.69 and 1.97% in terms of relative error, respectively. The percentage recovery obtained for AML and ROS in pharmaceutical preparations were 99.5 and 100.2%, respectively. Limit of detection and quantification for AML were 0.70 and 2.10 µg/mL, for ROS 0.80 and 2.40 µg/mL, respectively. Conclusion: The developed SWV method can be used for routine analysis of AML and ROS in pharmaceutical preparations.

Objectives: In this study, a new, fast and reliable differential pulse voltammetry (DPV) method was developed and validated for the simultaneous determination of amlodipine (AML) and hydrochlorothiazide(HCT) in pharmaceutical preparations. Methods: Electrochemical behavior and simultaneous voltammetric determination of AML and HCT were investigated using glassy carbon electrode. Validation parameters such as specificity, linearity, accuracy, precision, ruggedness, stability, limit of quantification and limit of detection were studied according to the International Conference on Harmonisation (ICH) Guidelines. Results: The linearity of this developed method was established in the concentration range of 2.5-30 μg/mL for AML and HCT, respectively. The precision was less than 5.34 and 2.91 %, determined from quality control samples for AML and HCT, and accuracy was within 2.57 and 3.60 % in terms of relative error, respectively. The percentage recovery obtained for AML and HCT in pharmaceutical preparations were 99.6 and 100.1 %, respectively. Limits of detection and quantification for AML and HCT were 0.80 and 2.40 µg/mL, respectively. Conclusion: The developed DPV method can be used for routine analysis of AML and HCT in pharmaceutical preparations.

Abstract: Objectives: The study aimed to develop and validate a simple UV-spectrophotometric method for quantifying Wintergreen oil in micro/nanosponges. Materials and Methods: The method was developed using acetonitrile as a solvent system and validated for various parameters such as linearity, precision, repeatability, the Limit of Detection (LOD), and the Limit of Quantification (LOQ), and accuracy according to ICH guidelines. Results: The oil showed an absorption maximum at 237nm. Linearity between concentration and absorbance was established within a concentration range of 2 to 28 mcg/mL and showed a regression coefficient of 0.9746. The recovery of 97.14-107.82% and % RSD of less than 2% for repeatability, intraday, inter-day, and ruggedness revealed that the method is accurate and precise. The LOD and LOQ were determined as 0.103 mcg/mL and 0.312 mcg/mL respectively. Insignificant changes in absorption values with deliberate variation in absorption maximum indicate the method's robustness. The entrapment efficiency and loading capacity ranged between 88-97.82% and 3.085-24.35%. Conclusion: The validation results conclude that the method is simple, sensitive, precise, accurate, and robust. Hence, the method was used for quantifying wintergreen oil in micro/nanosponges. The procedure can further be adapted for analysing wintergreen oil in other pharmaceutical preparations and commercial products. Keywords: Wintergreen oil, UV-spectrophotometry, Validation, Micro/nanosponges, Pharmaceutical formulation.