Phosphorimetric Determination of Dipyridamole in Pharmaceutical Preparations

Abstract

Room temperature phosphorescence was applied to the determination of dipyridamole in pharmaceutical preparations. The response was linear in the concentration range 100-1600 ng ml-1. The use of phosphorescence enhancers such as thallium(I) nitrate (external heavy atom), sodium dodecyl sulfate (microemulsion stabilizer) and sodium sulfite (deoxygenation agent) was studied and optimized to obtain maximum sensitivity and adequate selectivity. The determination was performed in 0.026 M sodium dodecyl sulfate, 0.0156 M thallium nitrate and 0.02 M sodium sulfite. The pH value was 11.5, adjusted by adding sodium hydroxide. The phosphorescence was totally developed in 15 min, after that the intensity was measured at lambda ex = 303 nm and lambda em = 616 nm. The recovery of the method was tested on commercial formulations containing dipyridamole. The recoveries obtained were 94.67 +/- 0.58% for Persantin and 96.75 +/- 1.37% for Asasantin. The overall least squares regression method was applied to find the most exact straight line that fits the experimental data. The detection limit according to the error propagation theory was 16.4 ng ml-1. The repeatability and relative standard deviation were also determined according to this theory.

An overview of qualimetric strategies for optimisation and calibration in pharmaceutical analysis using flow injection techniques

“…However, another disadvantage of the Simplex methods is the large number of experiments needed to reach the optimum, such as in the contribution by Vannecke et al [24], in which the modified Simplex was used to optimise two and three chemical variables, in the system previously described; nevertheless 14 and 21 steps were necessary, respectively. Murillo Pulgarín et al [18] have also used the modified Simplex method to optimise the room temperature phosphorescence variables in the determination of naftopidil by FIA. Simultaneous optimisation of four responses (sensitivity, precision, cost and sample throughput) using a multicriteria response function was proposed by Vereda et al [40] by using the modified Simplex method.…”

“…The most common option implies the selection of the analytical signal obtained from the detector, which is monitoring a transient concentration variation in relation to the nature of the analyte and the selected chemical system. Different detectors have been used in the analysis of pharmaceuticals by FIA making it possible to consider different responses such as the absorbance in the UV/Vis region [11,12,13,14], the chemiluminescence intensity [15,16,17] or the phosphorescence intensity [18]. Also, different analytical signals have been used, such as the peak height [19,20,21,22,23,24,25] or the residence time [21].…”

Simultaneous determination of two anti-inflammatory drugs in serum using isopotential fluorimetry

“…6MNA shows a slightly intensity increase up to a pH of 7.5 units and finally shows a decrease on the higher pH values. The influence of pH on the fluorescence intensity of serum was examined in previous work [30] and found to be nearly constant over the range Fig. 1 -Isometric representation of the total fluorescence spectra of: serum (dilution 1/200) (a), 6MNA (200 ng mL −1 ) (b) and diflunisal (1000 ng mL −1 ) (c).…”

Sensitive and simple determination of the vasodilator agent dipyridamole in pharmaceutical preparations by phosphorimetry

“…Micelle-stabilized room temperature phosphorescence (RTP) combined with sodium sulfite as an oxygen scavenger has permitted the determination of dipyridamole in different matrices in solution [7,8].…”

“…Although HPLC methods have several advantages, one serious problem for the determination of this compound in biological fluids is in preliminary procedures applied to the sample, such as extraction and concentration in organic solvents. Several spectrophotometric methods [3,4] and fluorimetric methods [5,6] have been described.…”