USP Method for Fexofenadine and Pseudoephedrine Identification Test B Using TLC Plates

By: Dr. Sanjay Poman, Merck KGaA, Darmstadt, Germany, Life Science Application Centre (GAC), Mumbai, India

Introduction

Fexofenadine is a selective peripheral H1-blocker, an antihistamine drug, used in the treatment of allergy symptoms such as hay fever and urticaria. Pseudoephidrine is a sympathomimetic drug of the phenethylamine and amphetamine chemical classes. It may be used as a nasal/sinus decongestant, as a stimulant, or as a wakefulness-promoting agent in higher doses.

Current US pharmacopeia (USP41-NF36) Fexofenadine and Pseudoephidrine extended-release tablets monograph indicates that an adsorbent having 0.2 mm layer of HPTLC silica gel should be used for the identification test B.

Here we demonstrate compliance with the identification test method, using appropriate reference standards, high purity solvents and reagents, together with HPTLC plates.

Fexofenadine Hydrochloride

Fexofenadine Hydrochloride

2-(4-(1-Hydroxy-4-(4-(hydroxydiphenylmethyl)piperidin-1-yl)butyl)phenyl) -2-methylpropanoic acid

Pseudoephidrine Hydrochloride

Pseudoephidrine Hydrochloride

(1S,2S)-2-(methylamino)-1-phenylpropan-1-ol

 

Experimental Conditions
TLC Plate 0.2 mm layer of HPTLC Silica Gel F254  20x10 cm (Dry the plate at 105 °C for 1 h before use)
Injection volume 10 µL
Detection Examine under ultra violet light at 254 nm
Mobile Phase Toluene:dehydrated alcohol:ammonium hydroxide 50:45:5 (v/v/v) 
Plate development Proceed as directed, using the developing solvent system (mobile phase). After removal of the plate, mark the solvent front, and allow the plate to air dry. Heat the plate at 105 °C until the odor of ammonia disappears (about 5 minutes). Allow the plate to cool and examine under UV light at 254 nm.
Note—The RF values for fexofenadine and pseudoephedrine are 0.17 and 0.39, respectively
Development Over 2/3rd of the plate
Diluent Toluene:dehydrated alcohol:ammonium hydroxide (50:45:5)
Drying Dry in air. Heat the plate at 105 Degree centigrade until the odour of ammonia disappears.
Standard A) 6 mg/mL of Fexofenadine in methanol
B) 12 mg/mL of pseudoephedrine hydrochloride in methanol
Sample Transfer the equivalent of 30 mg of fexofenadine and 60 mg of pseudoephedrine from finely divided powder tablets (NLT 4) into a suitable vessel, and add 5 mL of methanol.
Cap the vessel and shake vigorously for 2 minutes. Pass the suspension through a suitable filter of 0.45 µm pore size. Use the filtrate.

 

HPTLC Plate after development

HPTLC Plate after development

Chromatogram

 

Fexofenadine Chromatographic Data (Standard Solution)

Chromatographic Data (Standard Solution)
 

    Compound   Rf    Area
1 Fexofenadine Hydrochloride 0.22 1271

Pseudoephedrine Chromatographic Data (Standard Solution)

Chromatographic Data (Standard Solution)
 

    Compound   Rf    Area
1 Pseudoephedrine 0.40 1302

Fexofenadine Hydrochloride & Pseudoephedrine Chromatographic Data (Standard Solution)

Chromatographic Data (Standard Solution)
 

    Compound   Rf    Area
1 Fexofenadine Hydrochloride 0.22 1307
2 Pseudoephedrine 0.40 1407

Conclusion

  1. Fexofenadine and Pseudoephedrine Retardation Factors (RF) are 0.22 and 0.40, respectively. The elution bands compare well among samples and standard solutions (A and B), thus meeting the method acceptance criteria.
  2. Our silica gel HPTLC plates can be used for the Fexofenadine and Pseudoephedrine identification test B in extended-release tablets, and together with the listed appropriate reference standards, high purity solvents and reagents you can comply to the US Pharmacopeia requirements.

Materials