Spectroscopic Estimation of Doxylamine Succinate in Tablets and Human Plasma by Formation of Ion-pair Complex
Narender Malothu *
Department of Pharmaceutical Analysis, KL College of Pharmacy, Koneru Lakshmaiah Education Foundation, Vaddeswaram, Guntur, AP, India.
Sowjanya Ravuri
Department of Pharmaceutical Analysis, Vijaya Institute of Pharmaceutical Sciences for Women, Enikepadu, Vijayawada, India.
Balakrishna Muthyala
Department of Pharmaceutical Analysis, Vijaya Institute of Pharmaceutical Sciences for Women, Enikepadu, Vijayawada, India.
Narayana Rao Alla
Department of Pharmaceutical Analysis, KL College of Pharmacy, Koneru Lakshmaiah Education Foundation, Vaddeswaram, Guntur, AP, India.
Anka Rao Areti
Department of Pharmaceutical Analysis, KL College of Pharmacy, Koneru Lakshmaiah Education Foundation, Vaddeswaram, Guntur, AP, India.
*Author to whom correspondence should be addressed.
Abstract
Aim: To develop a simple spectroscopic method for estimation of doxylamine (DOX) succinate in its tablet dosage form and human plasma with the aid of an ion-pair complex formation.
Methods: In this method, methyl orange (0.05 % w/v) dye was used to form an ion-pair complex in acetate buffer (1M; pH: 5.00) at 300 C ± 20C. The ion-pair complex formed was extracted with chloroform. The maximum absorbance for the ion-pair complex was measured at 420 nm.
Results and discussion: The method conditions were obeyed Beer's law in the concentrations ranging from 5-25 µg/mL of DOX succinate with a correlation coefficient (r2) of 0.992. The ion-pair (drug-dye) complex was formed in a 1:1 ratio which was demonstrated by Jobs' method of continuous variation. The method was satisfied the validation criteria as per ICH (Q2R1) guidelines. Accuracy studies showed 99.06-100.9 % recovery of the analyte. The responses of the precision and robustness were found within acceptable limits (<2% RSD). The LOD and LOQ values were found as 0.31 and 0.939 µg/mL, respectively.
Conclusion: The developed method was simple, specific, and economical and requires a short analysis time. Therefore it could be considered for precise analysis of DOX succinate in biological matrices.
Keywords: Doxylamine succinate, spectroscopy, ion-pair complex, methyl orange, linearity, method validation