Academic literature on the topic 'Method of Firordt'

Authors of article developed techniques of quantitative definition Triazavirin in water solutions with use of a method of a spectrophotometry. Three options of a method of a s spectrophotometry are used: direct spectrophotometry, spectrophotometry according to A.M. Firordt, a spectrophotometry with use of standard solution. For all techniques calculation of metrological characteristics is carried out. The developed techniques of quantitative definition were applicable for practical use in the pharmaceutical analysis. The relative error of quantitative definition Triazavirin in water solutions made 0.37%, 0.14% and 8.29% respectively for a direct spectrophotometry, a spectrophotometry with use of standard solution, a spectrophotometry according to A.M. Firordt.

Actuality. Nowadays, the problems of effectiveness and accessibility of dermatoprotective therapy and prevention of dermatological diseases are urgent. The complex use of metronidazole in combination with drugs of other pharmacological groups is particularly relevant and promising. The dosage form consisting of 0.1 g of Itraconazole, 0.1 g of metronidazole and Tizol gel up to 10 g, termed by us Metroitraconazole, can be used in dermatology, ophthalmology and gynecology as a bactericidal and antifungal agent.
 The aim of the study is to develop the method for the quantitative spectrophotometric determination of metronidazole and itraconazole in a soft dosage form on a titanium-containing base. Materials and methods. For the analysis, we used substances, ethanol solutions of Metronidazole and Itraconazole, an ointment with the conditional name Metroitraconazole, containing 1.0% of the preparations in the Tizol gel. The study was carried out by spectrophotometry in the ultraviolet region, using spectrophotometer SF-2000 (Russia).
 Results. The study of the absorption spectra and statistical processing of the finding demontstrated that spectrophotometric determination of Itraconazole and metronidazole demanded the wavelengths of 262 and 312 nm, with a relative error of 1.52% and 1.67%, respectively. As a result of the analysis of the soft dosage form, it was determined that the content of metronidazole calculated with the use of Firordt method and a simplified system of equations ranged 0.0987-0.1057 g, and Itraconazole ranged 0.0925-0.1055 g. These data conformed the acceptance criteria.
 Conclusion. The conducted research allowed us to develop and propose a method for the quantitative determination of itraconazole and metronidazole in Metroitraconazole ointment by means of spectrophotometric method. It allowed us to determine the content of drugs in the dosage form with an error not exceeding the standard deviations.

Aim. Development of a method of analysis of metronidazole and terbinafine in ointment «Metroterbinazol» using spectrophotometry. Materials and methods. A soft dosage form containing 0.1 g of metronidazole, terbinafine and 9.8 g of Tizol gel was used as the object of research. Pharmacopoeia reagents and the method of spectrophotometry were used for experimental work. Measurements were carried out on the SF-2000 spectrophotometer in the near ultraviolet region (λ = 210-340 nm). Results. To achieve this goal, we studied the electronic absorption spectra and optical characteristics of metronidazole and terbinafine in the substance, ethanol solution and in the presence of Tizol gel. The curve of ε (terb) – ε (met) to the wavelength observed a maximum at a wavelength of 223 nm, which corresponds to the maximum of absorption of terbinafine and is close to a less pronounced first absorption maximum of metronidazole (226 nm), also pronounced minimum at a wavelength of 312 nm, which is similar to the second maximum of absorption of metronidazole. The results obtained suggest that the optimal wavelengths are 223 nm and 312 nm. On an artificial mixture with a similar concentration of ingredients according to the prescription, testing was conducted for the analysis of drugs in the joint presence. As a result of experiments, it was found that the mass of metronidazole, found by the Firordt method and the simplified system of equations, is in the limit of 0.0959-0.1053 g, terbinafine – 0.1072-0.1110 g, which corresponds to the permissible deviations. Based on the research, a method for the spectrophotometric analysis of terbinafine and metronidazole in «Metroterbinazole» ointment has been developed that allows quantifying them within the permissible deviations provided for in the regulatory documentation. Conclusion. A method of spectrophotometric quantitative determination of terbinafine and metronidazole is proposed, which allows analyzing medicinal products with a relative error of ± 1.49-1.50% and establishing the quality of manufacturing of «Metroterbinazole» ointment within acceptable standards of deviations.

Ionogenic contrast preparations, Triombrast, Urographin and Trasograph containing the active pharmaceutical ingredient (APhI), sodium amidotrizoate, have a positive experience in medical diagnosis.
 Qualitative control of intermediate products of each stage of AFI to prevent the possibility of technological toxic impurities – a mixture of 3,5-dinitro- and 3,5-diaminobenzoic acids (3,5-dNBK and 3,5-dABK) in the composition of the target product for safety X-ray contrast drugs in their application is a pressing issue today.
 The aim of the work – to develop a method for determining the technological impurities of 3,5-dNBK and 3,5-dABK acids in the synthesis of amidotrizoate sodium using UV spectrophotometry, which will allow to determine these impurities without their preliminary separation both in the inter-operative process control and in the finished product.
 The objects of study are aqueous solutions of 3,5-dNBK and 3,5-dABK acids, as well as their binary mixtures. The absorption spectra of the analytes were recorded using a Specord UV VIS spectrophotometer in the ultraviolet region. Calculations of the concentrations of the investigated acids in the composition of their binary compositions were performed according to the Vierordt's method.
 It is found that the absorption maxima of aqueous solutions of 3,5-dNBK and 3,5-dABK are at wavelengths of 240 nm and 218 nm; in the experimental conditions, the molar absorption coefficient for 3,5-dinitrobenzoic acid was the same (e1240 = e1218) and was equal to 17 940 ± 150. For solutions of 3,5-diaminobenzoic acid, the molar absorption coefficients were different: for a wavelength of 218 nm, the molar e2218 = 28 890 ± 220 and at a wavelength of 240 nm e2240 = 10 770 ± 80.
 Based on the Firordt method, taking into account the molar absorption coefficients of the investigated acids, we determined mathematical formulas for the quantitative analysis of the composition of mixtures at different ratios of analytes within their total concentration 1–6·10-5 M. Spectrophotometric Vierordt's method of quantitative analysis of 3,5-dinitro- and 3,5-diaminobenzoic acids, as well as their binary mixtures in aqueous solutions can be applied in the industrial production of iodine-containing contrast agents, where in the first stages of synthesis, the corresponding nitrobenzoic acid is reduced. Strict control of the possible amount of impurities in the first stage of synthesis of sodium amidotrizoate – the main active ingredient of ionic iodine-containing X-ray contrast drugs (Triombrast, Urografin, Trasograph) – will improve the quality of the final product and will allow to reduce the final product.

Possibility of quantitative definition of mediborol in oil solutions is shown by the method of Firordta and least-squares method for spectrophotometric analysis. The developed technique appreciably allows us to increase the measurement accuracy as compared with the direct spectrophotometric analysis. The error of the analysis does not exceed 1,36% for solution of mediborol in peachy oil and 0,83% in olive oil.

Синтетичні барвники, на відміну від природних, термічно стійкі, дають яскраве та стійке забарвлення. Більшість з них шкідливі, та заборонені в Україні, тому досить важливо правильно ідентифікувати їх у харчових продуктах. Кожен барвник має свій характерний максимум поглинання, але при використані суміші барвників які мають близькі максимуми, спектри поглинання перекриваються.