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Plasma beta-carotene and retinol assay was performed by high pressure liquid chromatography (HPLC) in subjects with chronic renal failure or liver cirrhosis. In the same subjects blood prealbumin (PA) and retinol binding protein (RBP) were determined by immunological technique. A considerable increase of retinol and in a lesser extent of beta-carotene was noted in the blood of patients with renal insufficiency. In cirrhotic patients it was shown a marked decrease both of beta-carotene and retinol plasma concentrations. PA and RBP there were greatly increased in renal failure and decreased in liver cirrhosis. This results suggest that kidney and liver chronic failure interfere with vitamin A metabolism throughout their action on metabolic processes of synthesis and elimination of PA and RBP.

An experimental procedure is described in order to standardize a gaschromatographic method proposed for a collaborative study organised by the F.I.P. Committee for Laboratories and Official Drug Control Services, on the analysis of some oestro-progestinic formulations. The assayed combination was a standard mixture of lynestrenol, mestranol and d, 1-alpha-tocopherol: testosterone was included as internal standard; two combinations, differing only in the internal standard content as specified in the text, were used. The variability of the instrumental factor was investigated performing some sets of single experiments, each consisting of 5 successive injections of the same standard mixture, on the same day. For each single experiment and for each substance the mean value Rm of the ratios R (R=area of the peak for compound cpi/area of the peak of the internal standard) was estimated with its relative standard deviation (% s.d.). For each set of experiments the % s.d. values were elaborated, following the Bartlett test, in order to obtain the sigma intra % value for each set, as a measure of the instrumental factor. An experimental evidence was observed for the relationship existing between the instrumental factor value (sigma intra %) and the internal standard content, in the operating conditions fixed for the present gas chromatographic analysis, a lowering of the instrumental factor beeing observed with the higher level of testosterone content (internal standard) in the mixture.

Ferritin, an iron-containing protein widely diffused in nature, has the important biochemical function of being the principal reserve and regulator for Fe3+ levels in blood and tissue. Due to its natural, effectively non-toxic iron content, ferritin has been the object of strong interest in the development of pharmaceutical products for use in iron deficiency treatment. Therefore, the need has arisen for the analytical characterization of this industrial product, be it in the hydroglyceric solution or dry powder form. The main considerations for the characterization of industrial ferritin are the following: a) iron content in both the unmodified product and the precipitated protein; b) protein content and protein/iron ratio; c) protein identification by means of polyacrylamide gel electrophoresis (PAGE); d) confirmation of protein identity and evaluation of molecular weight by means of size exclusion chromatography; e) identification and evaluation of other components of bulk ferritin preparations such as preservatives, excipients for lyophilization, water and concomitant proteins. Eight different samples were examined using the above considerations. Among the qualitative and quantitative results reported, of particular interest are those obtained by means of size-exclusion high performance liquid chromatography (SEC-HPLC). With a UV "diode array" detector it is possible to discern the peaks for ferritin and its molecular aggregates from those of concomitant proteins and preservatives; furthermore, it is possible to evaluate their molecular dimensions. Using this method, the ferritin monomer and other protein fractions can be quantitatively analyzed either by calculating area percent distribution of the chromatographic peaks or by comparing the sample with a highly pure external standard of ferritin.(ABSTRACT TRUNCATED AT 250 WORDS)