Determinação espectrofotométrica de vitamina B2 (riboflavina) em formulações farmacêuticas empregando sistema de análises por injeção em fluxo

Abstract

Recebido em 16/9/99; aceito em 12/1/00 SPECTROPHOTOMETRIC DETERMINATION OF VITAMIN B 2 (RIBOFLAVIN) IN PHARMACEUTICAL FORMULATIONS USING FLOW INJECTION ANALYSIS. A flow injection spectrophotometric procedure exploiting merging zones is proposed for determining vitamin B 2 (riboflavin) in pharmaceutical preparations. The determination is based on the red-colored complex formation between vitamin B 2 and silver(I) which was measured at 520 nm. Vitamin B 2 was determined in four pharmaceutical preparations in the 1.0 to 50.0 mg L-1 concentration range, with a detection limit of 0.5 mg L-1. The recovery from three samples ranged from 98.0 to 104.0 %. The analytical frequency was 42 h-1 and r.s.d. were lower than 1% for solutions containing 10.0, 30.0 and 50.0 mg L-1 vitamin B 2 (n= 10). The results obtained in commercial formulations using the FIA procedure were in good agreement with those obtained by using a conventional fluorimetric procedure (r=0.9998) and also with the label values (r= 0.9997).

Electrochemical sensor based on bismuth-film electrode for voltammetric studies on vitamin B2 (riboflavin)

“…with a variety of detectors [17][18][19][20][21][22], electrochemiluminescence [23], capillary electrophoresis [24], spectrophotometry [25][26][27][28], flow injection analysis with spectrophotometric detection [29], spectroelectrochemistry [30], fluorescence [31] and microbiological analysis [32]. However, regulatory agencies such as the United States Pharmacopeia (USP) [33], the Association of Official Analytical Chemists (AOAC) [34] and the Brazilian Pharmacopoeia [35] recommended fluorescence as the official method.…”

Non-inclusion complexes between riboflavin and cyclodextrins

“…Thus, RF has great pharmacological potential, taking into consideration its physiological role, relative low cost and anticancer activity. However, the relatively poor water solubility and photosensitivity of RF limit its application [7,8] . We therefore decided to combine RF with cyclodextrins (CDs), as these cyclic oligosaccharides have been used extensively as successful drug delivery carriers.…”

“…However, the relatively poor water solubility and photosensitivity of RF limit its application. [7,8] We therefore decided to combine RF with cyclodextrins (CDs), as these cyclic oligosaccharides have been used extensively as successful drug delivery carriers. The interaction of amphiphile compounds with CDs may increase their water solubility, diminish their effective doses, decrease their toxic side-effects, and protect the compounds against dehydration, hydrolysis, oxidation and photodegradation.…”

Chemical stability study of vitamins thiamine, riboflavin, pyridoxine and ascorbic acid in parenteral nutrition for neonatal use

“…Vitamins are components of parenteral nutrition (PN) used for attending the daily requirements and supplying deficiencies in neonates and, in their majority, are instable [ 1 - 3 ]. The chemical degradation is the most usual cause of vitamin loss in the PN bag.…”