Determination of piroxicam by solid-phase spectrophotometry in a continuous flow system

Piroxicam

A comprehensive profile of piroxicam including the nomenclatures, formulae, elemental composition, appearance, uses and applications. The methods which were utilized for the preparation of the drug substance and their respective schemes are outlined. The physical characteristics of the drug including the ionization constant, solubility, x-ray powder diffraction pattern, differential scanning calorimetry, thermal behavior and spectroscopic studies are described. The methods which were used for the analysis of the drug substance in bulk drug and/or in pharmaceutical formulations including the compendial, spectrophotometric, electrochemical and the chromatographic methods are reported. The stability, toxicity, pharmacokinetics, bioavailability, drug evaluation, comparison, in addition to compiled reviews on the drug substance are involved. Finally, more than four hundred and fifty references are listed at the end of this profile.

Sensitive Electrochemical Monitoring of Piroxicam in Pharmaceuticals Using Carbon Ionic Liquid Electrode

Background:

Piroxicam is a non-steroidal anti-inflammatory drug. The prevailing clinical use and investigation of piroxicam necessitate a rapid and sensitive method for its determination. A carbon ionic liquid electrode, fabricated using graphite and the ionic liquid 1-octylpyridinium hexafluorophosphate (OPFP) was used as an electrochemical sensor for piroxicam determination.

Methods:

The surface of the proposed electrode was characterized by scanning electron microscopy. Cyclic voltammetry (CV) was applied to study the oxidation of piroxicam and to acquire information about the reaction mechanism. Differential pulse voltammetry was also used as an analytical technique for quantification of the sub-micromolar concentration of piroxicam.

Results:

One oxidation peak at 0.55V was observed at CILE. The oxidation peak at the CPE was weak, while the response was notably increased at the CILE. The proposed electrode exhibited interesting sensitivity towards the determination of piroxicam and the anodic peak current versus piroxicam concentration was linear in the ranges of 0.2-60 µM. The detection limit of 40 nM was achieved.

Conclusion:

The electroxidation process was irreversible and revealed adsorption controlled behavior. The method was successfully applied for the determination of piroxicam content in pharmaceutical samples.

Validated method for the determination of piroxicam by capillary zone electrophoresis and its application to tablets

Simple and rapid capillary zone electrophoretic method was developed and validated in this study for the determination of piroxicam in tablets. The separation of piroxicam was conducted in a fused-silica capillary by using 10 mM borate buffer (pH 9.0) containing 10% (v/v) methanol as background electrolyte. The optimum conditions determined were 25 kV for separation voltage and 1 s for injection time. Analysis was carried out with UV detection at 204 nm. Naproxen sodium was used as an internal standard. The method was linear over the range of 0.23-28.79 µg/mL. The accuracy and precision were found to be satisfied within the acceptable limits (<2%). The LOD and LOQ were found to be 0.07 and 0.19 µg/mL, respectively. The method described here was applied to tablet dosage forms and the content of a tablet was found in the limits of USP-24 suggestions. To compare the results of capillary electrophoretic method, UV spectrophotometric method was developed and the difference between two methods was found to be insignificant. The capillary zone electrophoretic method developed in this study is rapid, simple, and suitable for routine analysis of piroxicam in pharmaceutical tablets.

Analysis of piroxicam in pharmaceutical formulation and human urine by dispersive liquid-liquid microextraction combined with spectrophotometry

PURPOSE

Piroxicam, is non-steroidal anti-inflammatory and analgesic agent, which is widely used in the treatment of patients with rheumatologic disorders. A new analytical approach based on the dispersive liquid-liquid microextraction (DLLME) has been developed for the extraction and determination of PX in pharmaceutical preparation and human urine.

METHODS

From the PX standard solution or solutions prepared from real samples, aliquot volumes were pipetted into centrifuge tubes and mixed with acetate buffer at pH 3.0 and NaCl solution. The contents were subjected to the DLLME, so 700 µL of methanol containing 70 µL of chloroform was injected rapidly into a sample solution. A cloudy solution was rapidly produced and the PX extracted into dispersed fine droplets. The mixture was centrifuged, thus these fine droplets of chloroform were settled. The supernatant aqueous phase was readily decanted, then the remained organic phase was diluted with ethanol and the absorbance measured at 355 ± 3 nm against a reagent blank.

RESULTS

The main factors affecting the extraction efficiency such as pH, extraction and disperser solvent types and etc. were studied and optimized systematically. Under optimized conditions, the calibration graphs were linear over the range of 0.2 to 4.8 µg/mL. The limit of detection and relative standard deviation were found to be 0.058 µg/mL and 2.83%, respectively. Relative recoveries in the spiked samples ranged from 97 to 110%.

CONCLUSION

Using the developed method PX can be analyzed in pharmaceutical formulation and human urine sample in a simpler, cheaper and more rapid manner.

A single spectroscopic flow-through sensing device for determination of ciprofloxacin

A simple flow injection UV spectrophotometric sensing device was developed for the determination of ciprofloxacin. The method is based on its transient retention and concentration on Sephadex SP C-25 cation-exchange gel beads packed in the flow cell and the continuous monitoring of its native absorbance on the solid phase at 277 nm. The procedure is carried out without any derivatisation. Formic acid/NaOH 1.75 M at pH 2.2 is used as carrier solution in a simple monochannel FIA manifold. When the analytical signal reached the maximum value, ciprofloxacin was eluted from the solid support by the carrier solution itself. The response of the sensor was linear in the concentration range 0.5-10 microg ml(-1) with an RSD (%) of 0.79, a detection limit (3sigma criterion) of 0.035microg ml(-1) and a sampling rate of 16 h(-1). Application to the analysis of pharmaceutical samples testifies the utility of this sensor.