MOHSEN, A. Y. M. A. N. M., H. M. Lotfy, A. M. Badawey, H. Salem, and S. O. N. I. A. Z. ELKHATEEB, "APPLICATION OF THREE NOVEL SPECTROPHOTOMETRIC METHODS MANIPULATING RATIO SPECTRA FOR RESOLVING A PHARMACEUTICAL MIXTURE OF CHLORPHENOXAMINE HYDROCHLORIDE AND CAFFEINE", International Journal of Pharmacy and Pharmaceutical Sciences, vol. 5, issue 1, pp. 478-487, 2013. Abstract

Three spectrophotometric methods are presented for the determination of a binary mixture of Chlorphenoxamine hydrochloride (CPX) and Caffeine (CAF) in laboratory prepared mixture and pharmaceutical dosage form without prior separation. Method (I) is an extended ratio subtraction method (EXRSM) coupled with ratio subtraction method (RSM), which depends on subtraction of the plateau values from the ratio spectrum. Method (II)is a ratio difference spectrophotometric method (RDSM), which depends on the difference in value between two different wavelengths of the ratio spectrum. Method (III) is a mean centering of ratio spectra (MCR). Mathematical explanation of the three methods is illustrated. Calibration curves of the three methods are linear over the concentration ranges of 4-24 μgml-1 and 2-24 μgml-1 for CPX and CAF, respectively. The three methods proved to be simple, specific, accurate and precise. Solvent used is double distilled water. The three methods are validated as per the ICH guidelines where accuracy, precision, repeatability and robustness are found to be within the acceptable limits.

El-Aleem, A. E. - A. A. B., S. M. Khalile, A. M. Badawy, and O. K. El-Naggar, "HPLC and TLC-Densitometric Methods for the Determination of some Antimigraine Drugs in Bulk Powder and in Pharmaceutical Preparations", Research J. Pharma. Dosage Forms and Tech, vol. 5, issue 5, pp. 289-295, 2013. Abstract

Two simple and accurate chromatographic methods were developed for the
determination of zolmitriptan, and sumatriptan in raw material and in tablets.
The first method uses isocratic high performance liquid chromatographic
(HPLC) method. Analysis was performed on Agilent Zorbax C18 column
using a mobile phase consisting of phosphate buffer pH3: acetonitrile:
methanol (2:1:1, v/v/v) with a flow rate of 0.75 ml/ min and UV detection at
253 nm. The second method uses thin-layer chromatographic (TLC)
separation of sumatriptan, zolmitriptan and eletriptan from their impurities
followed by densitometric measurements of drug spots at 254 nm. The
separation was carried out on silica gel 60 F254 using chloroform:
ethylacetate: methanol: ammonia (72:10:18:2, v/v/v/v) as mobile phase. The
methods were validated according to ICH guidelines and the acceptance
criteria for linearity, accuracy, precision, specificity and system suitability
were met in all cases. The methods were linear in the range of 10-40 μg/ml
and 10-50 μg/ml for zol. and sum. respectively by HPLC method and in
range of 1-20 μg/spot, 1-20 μg/spot and 1-10 μg/spot for ele., sum. and zol.
respectively by TLC method. The proposed methods were successfully
applied for the determination of zol., sum. and ele. in bulk and tablets forms.
The results were compared statistically at 95% confidence level with
reported methods. There was no significant difference between the mean
percentage recoveries and precision of the methods.

El-Aleem, A. E. - A. A. B., S. M. Khalile, A. M. Badawy, and O. K. El-Naggar, "Simultaneous Determination of Paracetamol and Metoclopramide in Antimigraine Pharmaceutical Formulations", Research J. Pharma. Dosage Forms and Tech, vol. 5, issue 5, pp. 270-274, 2013. Abstract

This paper describes sensitive, accurate and precise TLC- densitometric and
high performance liquid chromatographic (HPLC) methods for simultaneous
determination of paracetamol and metoclopramide in pharmaceutical
formulation. The TLC method employed aluminum TLC plates precoated
with silica gel F254 as the stationary phase and ethylacetate/ methanol/
ammonia (85:10:5 v/v/v) as the mobile phase, where the chromatogram was
scanned at 254 nm. The developed HPLC method used a Zorbax C18 column
with isocratic elution. The mobile phase composed of phosphate buffer pH
4.0: methanol (75:25 v/v) at flow rate of 1.0 ml/min. Quantitation was
achieved with UV detection at 273 nm. The methods were validated
according to the International Conference on Harmonization (ICH)
guidelines. The selectivity of the proposed methods was tested using
laboratory-prepared mixtures. The developed methods were successfully
applied for the determination paracetamol and metoclopramide in bulk
powder and combined dosage form.