Estimation of Levodopa in the Unani Drug Mucuna pruriens Bak. and Its Marketed Formulation by High-Performance Thin-Layer Chromatographic Technique

J AOAC Int. 2020 Jun 1;103(3):678-683. doi: 10.5740/jaoacint.19-0288.

Abstract

Background: Mucuna pruriens Bak. Syn. Mucuna prurita Hook. seed is the rich source of levodopa (L-dopa) and has been used in traditional medicines to treat diseases resembling Parkinson's disease.

Objective: In the present study, a new HPTLC method was developed and validated for estimation of L-dopa from M. pruriens (black- and white-colored seeds) collected from two different locations in India.

Method: TLC aluminum plates precoated with silica gel were used as the stationary phase. The plates were developed to a distance of 60 mm at a temperature of 22 ± 4°C in a twin glass chamber saturated with ethyl acetate-methanol-formic acid-water (15+3+3+4.5, v/v/v/v), as the mobile phase.

Results: The Rf value of L-dopa was found to be 0.45. L-dopa was quantified at 282 nm, the wavelength of maximum absorbance by a densitometric scanner. The TLC plate was derivatized by ninhydrin reagent and photodocumented. L-dopa showed a good linearity in the concentration range 400-1000 ng/spot. The linear regression analysis of calibration plot showed good linear relationship between peak area and peak height (r2 = 0.997).

Conclusions: The method was validated for precision, repeatability, and accuracy. Recovery was determined by spiking L-dopa with samples and was found to be 96.10%.

Highlights: L-dopa was found to be present at concentration 3.02-4.72% in samples and its formulation.

MeSH terms

  • Chromatography, Thin Layer
  • India
  • Levodopa / analysis
  • Mucuna*
  • Pharmaceutical Preparations*

Substances

  • Pharmaceutical Preparations
  • Levodopa