RESUMO
Entre as classes terapêuticas analisadas no Programa Nacional de Verificação da Qualidade de Medicamentos (PROVEME), o antifúngico fluconazol constava na apresentação de cápsulas de diferentes procedências. Na realização dos ensaios de dissolução conforme as técnicas dos fabricantes, constatou-se que os valores obtidos por espectrofotometria-UV foram superiores aos obtidos nos ensaios de teor e uniformidade de conteúdo, cuja determinação foi por CLAE-UV. Considerando este fato, foi objetivo deste trabalho realizar o ensaio de dissolução destas amostras pelos respectivos métodos dos fabricantes e o quantitativo do ensaio por espectrofotometria no UV e por CLAE-UV, a fim de avaliar as possíveis interferências dos excipientes nestas determinações. Os valores obtidos por espectrofotometria foram superiores aos obtidos por CLAE, confirmando a interferência dos excipientes. Concluiu-se que a metodologia a ser empregada na análise de fármacos deve ser criteriosamente selecionada, a fim de evitar resultados não condizentes com a real formulação do produto.
Among the therapeutic classes analyzed in the Programa Nacional de Verificação da Qualidade de Medicamentos (PROVEME) consisted the antifungal fluconazole in the dosage form of capsules from different origins. In dissolution tests, according to manufacturers techniques, it was found that the values obtained by UV-spectrophotometry were higher than those obtained from tests of content and content uniformity, whose determination was by HPLC-UV. Considering this fact, the objective of this study was to perform the dissolution test of these samples by the respective manufacturers methods and the quantitative assay by UV-spectrophotometry and HPLC-UV, to evaluate possible interferences of excipients in these determinations. The values obtained by spectrophotometry were higher than those obtained by HPLC, confirming the excipients interference. It was concluded that the methodology to be employed in drug analysis should be carefully selected in order to avoid results not commensurate with the real product formulation.
Assuntos
Humanos , Dissolução , Fluconazol , Cápsulas , EspectrofotometriaRESUMO
We investigated the specific sequence changes produced by the dietary mutagen 2-amino-1-methyl-6-phenylimidazo-[4,5-b]pyridine (PhIP) in UV5P3 cells [a Chinese hamster ovary (CHO) cell line]. Sequence analysis of the PhIP-induced mutations in the adenine phosphoribosyltransferase (aprt) gene, which is heterozygous in the UV5P3 cells, can provide insight into the mutagenic mechanism in these repair-deficient cells expressing P4501A2. Two allele-specific 20 mer oligonucleotide primer pairs were used in the polymerase chain reaction and the allele of interest was amplified. Single-base transversions occurred in 31/32 PhIP-induced mutants; of these, 6 were A.T-->T.A, 18 were C.G-->A.T and 6 were G.C-->T.A. Twenty of the 30 changes altered specific amino acid sequences and the other 10 resulted in a stop codon. On mutant had a change from C.G-->G.C at the 3' splice site of intron 4, thereby creating a new AG splice acceptor site. Another mutant had an insertion of T within a run of repeated sequences and resulted in a frameshift mutation. There were three 'hot-spots', two at the 3' end of exon 2 and one at the beginning of exon 3; 6 (19%) mutants showed a change from A.T-->T.A (exon 2, amino acid residue 57), 11 (34%) mutants from C.G-->A.T (exon 2, amino acid residue 62), and 7 (22%) mutants from C.G-->A.T (exon 3, amino acid residue 66). Consequently, 75% of the mutations were observed at these three sites. In contrast, none of the 20 spontaneous mutants had alterations at these hotspot sites. The mutations induced by PhIP in these repair-deficient CHO cells were unique and specific, and suggest that these sequences, if found in important genes controlling cell replication and survival, may be more susceptible to mutation from these food mutagens than genes not containing these sequences.