Resumo (PT):
Received on 08-10-2010 Accepted on 25-10-2010 Several commercial brand and generic formulations containing sodium valproate (NaVA) alone or in different combinations of this with valproic acid (VAac) were assayed using a clean automatic approach. To accomplish it, a sequential injection analysis based system coupled to potentiometric detection was exploited. The dissolution tests were performed at pH 6.8 where valproic acid (VAac) is quantitatively converted to its anionic form. Valproate ion selective electrode (VA-ISE) plus reference electrode or the VA-ISE plus a sodium ion selective electrode (Na +-ISE) were integrated as detectors in the system, to respectively obtain single global dissolution profiles of valproate (VA-) or simultaneous dissolution profiles of Na + and VA- ions. The system harvested 300 µL of the dissolution medium to process measurements within a time window of approximately 2 min in the intervals of 1-8.0x10-3 mol/L concerning VA-, and 3-8x10-3 mol/L in Na + ion. The proposed flow setup was able to efficiently discriminate profiles of generics and brand formulations, and also between forms containing different VAac/NaVA relative proportions, only with the spent of a pH/ionic strength adjusting buffer solution used as carrier in the system.
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<a target="_blank" href="http://www.ijptonline.com/archives/volume-2/issue-4"> Texto integral </a>
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Abstract (EN):
Received on 08-10-2010 Accepted on 25-10-2010 Several commercial brand and generic formulations containing sodium valproate (NaVA) alone or in different combinations of this with valproic acid (VAac) were assayed using a clean automatic approach. To accomplish it, a sequential injection analysis based system coupled to potentiometric detection was exploited. The dissolution tests were performed at pH 6.8 where valproic acid (VAac) is quantitatively converted to its anionic form. Valproate ion selective electrode (VA-ISE) plus reference electrode or the VA-ISE plus a sodium ion selective electrode (Na +-ISE) were integrated as detectors in the system, to respectively obtain single global dissolution profiles of valproate (VA-) or simultaneous dissolution profiles of Na + and VA- ions. The system harvested 300 µL of the dissolution medium to process measurements within a time window of approximately 2 min in the intervals of 1-8.0x10-3 mol/L concerning VA-, and 3-8x10-3 mol/L in Na + ion. The proposed flow setup was able to efficiently discriminate profiles of generics and brand formulations, and also between forms containing different VAac/NaVA relative proportions, only with the spent of a pH/ionic strength adjusting buffer solution used as carrier in the system.
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<a target="_blank" href="http://www.ijptonline.com/archives/volume-2/issue-4"> Full text </a>
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Idioma:
Inglês
Tipo (Avaliação Docente):
Científica