Adsorption Decolorization Of The Coloring Matters In Griseofulvin Extraction Liquor By Macroporous Resins

Effectiveness for removing coloring matters from griseofulvin(GF) extraction liquor exerts direct influence on Griseofulvin product quality. The main problems resulting from the active carbon discolorization from GF extraction liquor in industry are the entrainment of GF in active carbon and environmental pollution due to pile-up and disposal of spent active carbon. The purpose of the present work was to explore technological conditions of decolorization with macroporous resins in order to provide reference basis for the design and control in industry process.Exploring experiments were conducted to select proper macroporous resins for removing coloring matters from Griseofulvin extract liquor. Static and dynamic tests were performed to find the proper operating conditions for removing coloring matters by macroporous resin. This paper presented the stability of resin regeneration and adsorption isotherm, and compared the specifications of Griseofulvin obtained by active carbon and macroporous resin decolorization method, respectively.The results suggest that macroporous resin D301T is of high efficiency as adsorbent for removing coloring matters from Griseofulvin extract liquor, which is weak alkalescence anion exchang resin. The appropriate conditions of D301T resin for decolorization are as follows: the quantity of extract solution, 50ml;resin mass, 3g; adsorption equilibrium time, 20 min; operating temperature, 35℃; pH within 5.0～6.0. Adsorption isotherm is in agreement with Freundlich model, and the process belongs to favourable adsorption. The desorption efficiency is preferable using 1.0mol/L NaOH solution as desorbent.The dynamic tests show that the appropriate flowrate of extract liquor is 3 ml/min for adsorption process when the GF extract liquor volume disposed is 900ml, and desorbent flowrate is 4ml/min in the regeneration process when desorbent dosage ranges from 220 to 350 ml. The resin could be used repeatedly for six times in the process of adsorption and desorption, with the GF yield unchanged.Griseofulvin sample is characterized by TEM, and the results indicate a narrow particle size distribution, in which 95% of microparticles is within 5μm. The most of GF particles are spheroidal or like-spheroidal. The specifications are in accordance with the GF standards in the Pharmacopoeia of the People Republic of China, and the whiteness and purity of GF sample treated by D301T resin are superior to those of the sample dealed with active carbon.