Tropical Journal of Pharmaceutical Research

Original Research Article | OPEN ACCESS

Novel ratio subtraction and isoabsorptive point methods for determination of ambroxol hydrochloride and doxycycline in their combined dosage form: Development and validation

Hany W Darwish^1,2 , Fadia H Metwally^2,3, Abdelaziz El Bayoumi²

¹Department of Pharmaceutical Chemistry, College of Pharmacy, King Saud University, PO Box 2457, Riyadh 11451, Saudi Arabia; ²Department of Analytical Chemistry, Faculty of Pharmacy, Cairo University, Kasr El-Aini Street, ET 11562, Cairo, Egypt, 3Ibn Sina National College for Medical Studies, Jeddah, AlMahjer Road, Saudi Arabia.

For correspondence:- Hany Darwish Email: hdarwish75@yahoo.com,hdarwish@ksu.edu.sa Tel:+966-14677343

Received: 15 October 2014 Revised: 22 December 2014 Published: 30 January 2015

Citation: Darwish HW, Metwally FH, Bayoumi AE. Novel ratio subtraction and isoabsorptive point methods for determination of ambroxol hydrochloride and doxycycline in their combined dosage form: Development and validation. Trop J Pharm Res 2015; 14(1):133-140 doi: 10.4314/tjpr.v14i1.19

© 2015 The authors.
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Abstract

Purpose:To develop and validate two innovative spectrophotometric methods used for the simultaneous determination of ambroxol hydrochloride and doxycycline in their binary mixture.

Methods:Ratio subtraction and isoabsorptive point methods were used for the simultaneous determination of ambroxol hydrochloride and doxycycline in their binary mixture. Linear correlations were obtained in the concentration range of 6 - 40 and 4 - 32 µg mL^-1 for ambroxol hydrochloride and doxycycline, respectively. Ratio subtraction method was utilized for determination of ambroxol hydrochloride at 246.5 nm while isoabsorptive point method was employed for doxycycline at 244 nm (using methanol as a solvent) in mixtures as well as in their combined dosage form (Ambrodoxy capsules).

Results:The proposed methods were successfully applied to the analysis of the pharmaceutical capsules containing the two analytes. Recovery for ambroxol hydrochloride and doxycycline in capsules was 99.49 and 99.96 %, respectively. The relative standard deviation (% RSD) for the assay of the capsules was < 1 %. Validation of the two methods was assessed according to International Council on Harmonization (ICH) guidelines regarding linearity, accuracy, precision, specificity and range. The results of the proposed methods compared favorably with those obtained by a reported chemometrics-assisted ultraviolet (UV)-spectroscopic method.

Conclusion:The proposed methods are rapid, selective, simple and accurate. They also represent suitable alternatives to the chromatographic methods currently used for the analysis of the pharmaceutical mixtures in various dosage forms.

Keywords: Ambroxol, Doxycycline, Ratio subtraction method, Isoabsorptive point method, Binary mixture, Spectrophotometry