HOME > Journals > Pharmaceutical Journal of Kenya, Volume 23, No. 3 (2018) > Development and Validation of a Gas Ch...

Development and Validation of a Gas Chromatographic Method for Determination of Menthol in Cold-Cough Syrups

Author: Aluda A.T , Amugune B.K , Abuga K.O , Kamau F.N.
Is Part Of: Pharmaceutical Journal of Kenya, Volume 23, No. 3 (2018)
Abstract:
Background
Common cold is the most common infection of the upper respiratory tract and cold-cough syrups are often prescribed. Although menthol is one of the common constituents of these syrups, quality checks on cold-cough syrups normally target the major active pharmaceutical ingredients without regard to menthol content.
Objective
To develop and validate a gas chromatography method for determination of menthol in cold-cough syrups.
Methods
A simple, rapid, robust, accurate and reliable Gas Chromatography method was developed and validated for the determination of menthol in cold-cough syrups that may also contain ambroxol, chlorpheniramine, guaifenesin, bromhexine and salbutamol.
Results
Optimized chromatographic conditions were: A ZB-WAXplus 60m ×0.25mm; 0.25μm fused silica capillary column. Oven temperature program of 110 0C (2 min), ramp 10 0C/min to 190 0C (2 min). Injector port temperature maintained at 240 0C. Injection volume of 1.0 μl split in the ratio of 50:1. Carrier gas as nitrogen at 1.0mL/min which also serves as make up gas (30 mL/min) in the flame ionization detector (260 0C). Other detector gases were hydrogen (30 mL/ min) and industrial air (300 mL/ min) and the diluent for samples and standards was grade chloroform.
From recovery studies, 97.56 to 102.97 % recovery was reported. Repeatability studies had a coefficient of variation of 0.55 while intermediate precision was 0.32. The method was linear over a range of 0.042 to 0.169 mg/mL with a coefficient of determination (R2) 0.9986.
Of the 21 samples analyzed, only 10 samples (47.6 %) complied with assay specifications of 90.0 to 110.0 % label claim for finished products according to the United States Pharmacopeia 2016.
Development and Validation of a Gas Chromatographic Method for Determination of Menthol in Cold-Cough Syrups
Aluda A.T , Amugune B.K , Abuga K.O , Kamau F.N.
Department of Pharmaceutical Chemistry, School of Pharmacy, University of Nairobi, P.O. BOX 1967-00202, Nairobi, Kenya, Email: adeya.tiberius@gmail.com
*Corresponding Author
Conclusion and recommendation
A gas chromatographic method was developed and validated for the determination of menthol in cold-cough syrups in Kenya. This method can be used together with a validated high-performance liquid chromatography method to assay cold-cough syrups that may also contain ambroxol, bromhexine, chlorpheniramine maleate, guaifenesin and salbutamol.
This method can be useful in routine analysis such as pre-registration studies as well as post market surveillance to curb substandard and counterfeit cold-cough syrups.

Keywords: Capillary column, monoterpene, organic layer, carrier gas, total menthol, cold-cough syrup
Publisher: The Pharmaceutical Society of Kenya
ISSN: 2411-6386
DOWNLOAD ARTICLE.