[Turbidimetric determination of tenoxicam using molybdophosphoric acid].
A turbidimetric method was developed for tenoxicam quantification using the complexing reaction with molybdophosphoric acid in hydrochloric acid medium; the complex has a maximum of absorbance at 369 nm.


METHODS
The practical working conditions were established. In the 2.5 division by 15.0 microg/mL concentration range of tenoxicam in 1N hydrochloric acid, were added 1 mL of 1% molybdophosphoric acid solution and 1 mL of 0.1% sodium lauryl sulphate. The stability of product was evaluated over 60 minutes. The developed method was validated.


RESULTS
The method showed a good linearity in the range of 2.5 division by 15.0 microg/mL (the correlation coefficient r = 0.9996). The detection limit (LD) was 0.44 microg/mL and the quantification limit (LQ) was 1.47 microg/mL. There were established the precision (RSD = 1.82%) and the accuracy (mean recovery is 100.79% in 97.55 division by BY 04.41% the range).


CONCLUSIONS
The experimental results demonstrated a good sensibility. The specific absorptivity for this method is A(1cm,369nm)(1%) higher than tenoxicam in hydrochloric acid medium A(1cm,354nm)(1%).
Universitatea de Medicină şi Farmacie Gr. T. Popa Iaşi, Facultatea de Farmacie, Disciplina de Chimie Analitică.
Andreea Elena
AE
Muraraşu
Mariana
M
Mândrescu
V
V
Dorneanu
D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000032:analysis* / Q000737:chemistry; D016861:Cyclooxygenase Inhibitors / Q000032:analysis* / Q000737:chemistry; D004355:Drug Stability; D006851:Hydrochloric Acid / Q000737:chemistry; D008982:Molybdenum / Q000737:chemistry*; D009391:Nephelometry and Turbidimetry / Q000379:methods*; D010756:Phosphoric Acids / Q000737:chemistry*; D010894:Piroxicam / Q000031:analogs & derivatives* / Q000032:analysis / Q000737:chemistry; D015203:Reproducibility of Results; D012967:Sodium Dodecyl Sulfate / Q000737:chemistry
D000894:Anti-Inflammatory Agents, Non-Steroidal; D016861:Cyclooxygenase Inhibitors; D010756:Phosphoric Acids; D010894:Piroxicam; D012967:Sodium Dodecyl Sulfate; D008982:Molybdenum; D006851:Hydrochloric Acid; C003125:phosphomolybdic acid; C032801:tenoxicam