Indirect Spectrophotometric Determination of Mesalazine via Chromate-1,5-Diphenyl carbazide Complex

Abstract

A simple and rapid indirect spectrophotometric method for the determination of mesalazine is developed. The method is based on the rapid reduction of known large amount of chromate CrO 4-2 in the presence of mesalazine in acidic medium of 2N H 2 SO 4. The excess amount of chromate is measured after it's reaction with 1,5-diphenylcarbazide which finally gives a pink-violet, water soluble and stable complex, which exhibit a maximum absorption at 546 nm. Beer's law is obeyed in the concentration range from (5-900) µg of mesalazine in a final volume of 25 ml (0.2-36 ppm) with a molar absorbtivity of 1×10 5 l.mol-1 .cm-1 , Sandell's sensitivity index of 0.0015 µg .cm-2 and relative standard deviation ± 0.0848 to ± 0.3155 depending on the concentration level. The proposed method is applied successfully to the assay of mesalazine in its pharmaceutical prepearation (capsules). ‫ﻟﻠ‬ ‫ﺍﻟﻤﺒﺎﺸﺭ‬ ‫ﻏﻴﺭ‬ ‫ﺍﻟﻁﻴﻔﻲ‬ ‫ﺍﻟﺘﻘﺩﻴﺭ‬ ‫ﻤﻴﺯﺍﻻﺯﻴﻥ‬ ‫ﺍﻟﻜﺭﻭﻡ‬ ‫ﻤﻌﻘﺩ‬ ‫ﺒﺎﺴﺘﺨﺩﺍﻡ‬-5,1-‫ﻜﺎﺭﺒﺎﺯﻴﺩ‬ ‫ﻓﻨﻴل‬ ‫ﺜﻨﺎﺌﻲ‬ ‫ﺍﻟﻤﻠﺨﺹ‬ ‫ﺍﻟﺒﺤﺙ‬ ‫ﻴﺘﻀﻤﻥ‬ ‫ﺒﺴﻴ‬ ‫ﻤﺒﺎﺸﺭﺓ‬ ‫ﻏﻴﺭ‬ ‫ﻁﻴﻔﻴﺔ‬ ‫ﻁﺭﻴﻘﺔ‬ ‫ﺘﻁﻭﻴﺭ‬ ‫ﻟ‬ ‫ﻭﺴﺭﻴﻌﺔ‬ ‫ﻁﺔ‬ ‫ﺍﻟﻤﻴﺯﺍﻻﺯﻴﻥ‬ ‫ﺘﻘﺩﻴﺭ‬. ‫ﺘ‬ ‫ﻌﺘﻤـﺩ‬ ‫ﺍﺨﺘـﺯﺍل‬ ‫ﻋﻠـﻰ‬ ‫ﺍﻟﻁﺭﻴﻘـﺔ‬ ‫ﺍﻟﻜﺭﻭﻤﺎﺕ‬ CrO 4-2 ‫ﺍﻟﻜﺒﺭﻴﺘﻴﻙ‬ ‫ﺤﺎﻤﺽ‬ ‫ﺒﺎﺴﺘﺨﺩﺍﻡ‬ ‫ﺍﻟﺤﺎﻤﻀﻲ‬ ‫ﺍﻟﻭﺴﻁ‬ ‫ﻓﻲ‬ ‫ﺍﻟﻤﻴﺯﺍﻻﺯﻴﻥ‬ ‫ﺒﻭﺴﺎﻁﺔ‬) 2 ‫ﻋﻴﺎﺭﻱ‬ (‫ﻏﻴﺭ‬ ‫ﺍﻟﻜﻤﻴﺔ‬ ‫ﺘﻘﺩﻴﺭ‬ ‫ﺜﻡ‬ ‫ﻭﻤﻥ‬ ‫ﻭﺒﻴﻥ‬ ‫ﺍﻟﻤﺨﺘﺯﻟﺔ‬ ‫ﻏﻴﺭ‬ ‫ﺍﻟﻜﺭﻭﻤﺎﺕ‬ ‫ﺒﻴﻥ‬ ‫ﺍﻟﻤﺘﻜﻭﻥ‬ ‫ﺍﻟﻤﻠﻭﻥ‬ ‫ﺍﻟﻤﻌﻘﺩ‬ ‫ﺍﻤﺘﺼﺎﺹ‬ ‫ﻁﻴﻑ‬ ‫ﺒﻘﻴﺎﺱ‬ ‫ﺍﻟﻜﺭﻭﻤﺎﺕ‬ ‫ﻤﻥ‬ ‫ﺍﻟﻤﺨﺘﺯﻟﺔ‬ ‫ﺍﻟﻌـﻀﻭﻱ‬ ‫ﺍﻟﻜﺎﺸـﻑ‬ 5,1-‫ﺍﻟﻤﻭﺠﻲ‬ ‫ﺍﻟﻁﻭل‬ ‫ﻋﻨﺩ‬ ‫ﻜﺎﺭﺒﺎﺯﻴﺩ‬ ‫ﻓﻨﻴل‬ ‫ﺜﻨﺎﺌﻲ‬ 546 ‫ﻨﺎﻨﻭﻤﻴﺘﺭ‬. ‫ﺍﻟﺘﺭﻜﻴﺯ‬ ‫ﻤﺩﻯ‬ ‫ﻓﻲ‬ ‫ﺒﻴﺭ‬ ‫ﻗﺎﻨﻭﻥ‬ ‫ﺤﺩﻭﺩ‬ ‫ﻜﺎﻨﺕ‬) 5 (900-‫ﻤـﺎﻴﻜﺭﻭﻏﺭﺍﻡ‬ ‫ﺍ‬ ‫ﻤﻥ‬ ‫ﻟﻤﻴﺯﺍﻻﺯﻴﻥ‬ ‫ﻨﻬﺎﺌﻲ‬ ‫ﺤﺠﻡ‬ ‫ﻓﻲ‬ 25 ‫ﻤﻠﻠﺘﺭ‬ ، (0.2-36 ppm)