Comparative spectrophotometric evaluation and forced degradation study of caffeine in tablet and green tea extract

Abstract

Abstract:

Caffeine is used in worldwide as a central nervous system stimulant and its natural herbal source such as green tea also act as a central nervous system stimulant due to presence of caffeine . The present study aimed to perform a comparative UV spectrophotometric analysis of caffeine in a marketed tablet (cafergot ) containing caffeine and ergotamine and in green tea extract  .Green tea extract was prepared by taking 3.5 gram which has approximately 100mg as 1 gram of herbal tea leaves contain 25 to 30 mg of caffeine ,then by aqueous extraction, tea extract were obtained which is followed by filtration and appropriate dilution . Tablet was powdered , dissolved in distilled water ,filtered and diluted to obtain a clear solution .Absorbance were measured at 273 nm using UV spectrophotometer, with distilled water as blank and 1cm path length of cuvette. The absorbance of green tea extract was found to be higher than that of tablet solution under identical experimental conditions . This increased absorption maybe due to caffeine or to the presence of other UV absorbing phytochemicals, which are abundant in green tea and show  absorption in the same wavelength region. Forced degradation studies were performed to evaluate the stability of caffeine under acidic , basic and heat conditions. The samples were treated with 0.1N hydrochloric acid and 0.1N sodium hydroxide , and absorbance was measured using UV-Visible spectrophotometry . The result demonstrate that caffeine remains stable in acidic conditions and thermal conditions showing no significance change in absorbance for both tablet and green tea extract samples  . however under alkaline conditions , a slight decrease in absorbance was observed in tablet samples, indicating partial degradation . while tea extract showed higher absorbance due to possible matrix interference . These findings confirm that caffeine exhibits greater stability in acidic medium compared to alkaline medium. This study demonstrate that UV spectrophotometry is a simple , rapid, and cost effective method for comparative analysis of caffeine in pharmaceutical and herbal matrices , although selective quantification in herbal samples may require more specific techniques such as high performance liquid chromatography (HPLC). The findings highlights the importance of considering phytochemical interference when analyzing herbal products and support the applicability of spectrophotometric methods in comparative study between herbal source and its marketed tablet form.