0000000000064654
AUTHOR
A Moreno Gálvez
Simultaneous dissolution profiles of two drugs, sulfadiazine-trimethoprim and amitriptyline-perphenazine, in solid oral dosage forms by a FIA manifold provided with a single spectrophotometric detector
The simultaneous determination of two dissolution profiles with the aid of a Flow Injection Analysis assembly has been applied to: (a) sulfadiazine-trimethoprim in tablets and (b) amitriptyline-perphenazine in sugar coated pills. The selected combinations are drugs which have overlapping UV-vis spectra. The officially proposed procedure from the pharmacopoeias has been adapted for the FIA methodology and derivative spectrophotometry and zero crossing. Preliminary experiments on the suitability of the simultaneous determination of both drugs were performed. The empirical profiles were adjusted by regression analysis using different approaches. The 3-parameter plot method was finally selected…
Study of various indicating redox systems on the indirect flow-injection biamperometric determination of pharmaceuticals
Abstract The reversible redox couples (Fe(III)/Fe(II); Ce(IV)/Ce(III); Fe(CN) 6 3– /Fe(CN) 6 4− ; I 2 /I − ; Br 2 /Br − and VO 3 − /VO 2+ ) were studied as indicating redox systems for biamperometric determination of paracetamol in a flow injection assembly. Considering the selectivity of assayed systems against excipients and antioxidants that typically are presented in pharmaceutical formulations (e.g. sucrose, glucose, ascorbic acid and hydrogen sulphite) the systems Fe(III)/Fe(II) and VO 3 − /VO 2+ were selected for the determination of the drug. The sample was injected into a carrier which merged with the oxidant stream where the drug was oxidised by excess oxidant. The observed signal…
Simultaneous dissolution profiles of two drugs in pharmaceutical formulations by an FIA manifold
Abstract This article deals with the simultaneous determination of dissolution profiles of two drugs with overlapped spectra, present in the same pharmaceutical formulation. The official procedure for the dissolution profile is adapted to the continuous-flow methodology; the dissolution vessel is connected to an FIA manifold, in which the sample aliquots from the dissolution vessel are treated in order to adjust to the suitable pH and dilution degree to be monitored. The resulting solution is injected into the carrier stream, an acetic acid–acetate buffer at pH 4.3 and forced to the flow-cell of the spectrophotometer. The simultaneous determination of both profiles is based on the first der…