Quantitative determination of ruscogenin in Ruscus species by densitometric thin-layer chromatography.

A densitometric t.l.c. method of quantitative determination of ruscogenin was elaborated. After separation with the aid of t.l.c., the colourless ruscogenin spots were located with the aid of a p-dimethyl-aminobenzaldehyde solution and were submitted to densitometry. It was found that under the selected conditions a linear dependence exists between the betaI% value and lgC within the range of 0.5--10 mug ruscogenin. The determination of ruscogenin is done in the presence of the remaining components of the sample. The method is free of any systematic error. The method was applied in the determination of the ruscogenin content of the above-ground and underground part of Ruscus aculeatus and R. hypoglossum, extracts of the same plants, and capsules with further to the R. aculeatus extract also contained bioflavonoids. It was found that the content of ruscogenin in the underground and the above-ground parts of R. hypoglossum is 0.14 and 0.10%, respectively, while for R. aculeatus the respective values are 0.12 and 0.08%. The extract contains 1.6% ruscogenin, and the capsules 0.09 mg each.

Quantitative determination of drugs by means of densitometry of thin-layer chromatograms. Part 4: Determination of vitamins A and E in pharmaceutical preparations.

A quantitative method for the determination of vitamins A and E is proposed based on the direct densitometry of thinlayer chromatographic spots. An appropriate solvent system for the chromatographic separation of the vitamins and the conditions under which a linear relationship between the absorbed light and the logarithm of concentration exists (1--10 mug range) are found. The precision of the method is evaluated by a statistical treatment of the results. Satisfactory reproducibility is established-- the variation coefficient for the determination of the two vitamins is about 4--5%. The method is applied for the analysis of oil and aqueous injection solutions, mixtures containing the three vitamins A, E and D2 and some pharmaceutical preparations (Pharmavit¿ and Devitforte¿). The presence of the decomposition products and other substances (other pharmaceuticals, stabilizers, solubilizers etc.) does not affect the determination. The analysis is performed without preliminary treatment of the sample.

Quantitative determination of drugs by means of densitometry of thin-layer chromatograms. Part 5: Determination of the Vitamins B1, B2, B6 and B12 in mixture and in pharmaceutical preparations.

A quantitative t.l.c. densitometric method for the simultaneous determination of the water-soluble vitamins B1, B2, B6, and B12 is proposed. The four vitamins are determined on one and the same plate by direct densitometry of the t.l.c. spots. A preliminary separation of the vitamins one from another, as well as a preliminary separation from other pharmaceuticals is not necessary. The determination is performed quickly and easily. The relative standard deviations of a single determination are the following: for thiamine 6,6%, for riboflavin 5,5%, for pyridoxine 6,4%, and for cyanocobalamin 5,8%. The proposed method is applied to the determination of B-vitamins in three pharmaceutical preparations: ampoules B12 with B1, ampoules B-complex, and antisclerol dragee. The presence of other pharmaceuticals (vitamins C and PP, urethane, aminophenazone, phytin, rutin, theobromine, etc.) does not interfere with the determination.

Quantitative determination of drugs by means of densitometry of thin-layer chromatograms. Part 6 Determination of 1-benzhydril-4-allypiperazine dihydrochloride in biological media.

A quantitative method for determination of 1-benzhydril-4-allypiperazine dihydrochloride (As-2) in blood is proposed, based on direct densitometry of t.l.c. plates. The main advantage of the method consists in the fact that it can be applied for determination of As-2 in biological samples in the presence of its metabolites and other components of the investigated samples. The statistical treatment of results obtained from ten analyses shows that the method has no systematic error and the relative percentage error is +/- 8.5%. The lowest concentration which can be determined is 5 microng/1 ml plasma. It has been established that As-2 administered intravenously in the maximally tolerable dose of 22 mg/kg can be detected in the blood after the first min (RF = 0.45). Ten min after application one major metabolite (RF = 0.35) is observed under UV-light. When administered per os in the maximally tolerable dose of 100 mg/kg, As-2 is established in the blood after 15 min while the metabolite mentioned above is detected by the thirtieth min.