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Biomedical subjects

J Subert

Publications and source records attributed to J Subert.

At least 19 recordsLinked to original sources
PubMed1988

Problems connected with HPLC separation of pilocarpine from its degradation products by means of silica gel and water-based mobile phase.

HPLC separation of pilocarpine from its degradation products (isopilocarpine, pilocarpic acid and isopilocarpic acid) was studied on unmodified silica gel stationary phase. An acidified aqueous solution of inorganic salts with addition of methanol served as the mobile phase. The influence of silica gel used, methanol content, mobile phase pH, anion of acids and/or inorganic salts and column temperature on solute retention, separation selectivity as well as peak shape was studied and partly explained. A significant dependence of the properties of the resulting separation system on the silica gel used was found. A test was proposed for evaluation of silica gel suitability.

Chromatography, High Pressure Liquid↗
PubMed1979

Stability of acetylsalicylic acid in divided powders in the presence of aminophenazone.

The combination of acetylsalicylic acid with aminophenazone, often prescribed in divided powders, is considered to be incompatible. High performance liquid chromatography was applied to determine the content of salicylic acid which is the main known product from the decomposition of acetylsalicylic acid. The analysis of model samples containing a 1:1 (by weight) mixture of acetylsalicylic acid and aminophenazone, after having been stored under usual conditions in starch capsules, showed that the decomposition of acetylsalicylic acid into salicylic acid did not exceed 0.8% even after ten weeks.

Aminopyrine↗
PubMed1977

The use of borohydrides of alkaline metals in the volumetric analysis of medicaments.

The possibility and conditions of determination of weak acid type medicaments were examined, using aqueous and non-aqueous sodium borohydride volumetric solutions. The process and control of titration were carried out potentiometrically and visually using acido-basic indicators. It was shown that for practical applications sodium borohydride aqueous solutions are more suitable. Analytical methods of determination for medicaments from the group of sulphonamides and barbiturates and their sodium salts, for phenylbutazone and kebuzone, salicylamide, nalidixic acid and theophylline were elaborated. All results were in good agreement with methods used in CsL 3, or other alternative methods. The advantages of the proposed method are good stability of sodium borohydride volumetric solution and insensitivity of titrated systems to CO2 from the atmosphere, which is unavoidable with alkalimetric titrations in aqueous and non-aqueous systems. An hypothesis has been suggested to explain the probable reactive mechanism of determination, supported by results obtained with the proposed analytical methods using a medium of suitable organic solvents with a maximum content of ca. 15% water near the final point of titration.

Barbiturates↗