(200ac) One Step Purification of Curcumin from Its Lower Grades Via Particle Mediated Crystallization

One
step purification of curcumin from its lower grades via particle mediated
crystallization

K. Vasanth Kumar, KiranA.Ramisetty, Rama Krishna Gamidi,C. Heffernan, K. Renuka
Devi, B.K. Hodnett

and Åke C. Rasmuson

Synthesis and Solid State Pharmaceutical Centre, University of
Limerick, Limerick, Ireland.

E-mail:
vasanth.kannuchamy@ul.ie; ake.rasmuson@ul.ie

Purification
of organic molecules via crystallization is a challenging process. Conventional
methods rely on several recrystallization steps which are time consuming and
laborious. ¹ Alternatively, crystallization can be performed with
highly super-cooled solution and at very low temperature that can force the crystallizing
molecule to crystallize via a unique particle aggregation pathway (Figure 1) mediated
by perfectly and imperfectly aligned crystallites. In the presentation we will propose
the general mechanisms involved in this process (see Figure 1) and will show
experimental evidence to show particle mediated crystallization can produce >99%
and new form of pure curcumin in one-step from its lower grades that contains
at least 20% of structurally similar impurities. We will also show the
characteristic properties of the final crystals obtained using microscopic and
spectroscopic techniques (PXRD, SCXRD, SEM/TEM and HPLC). 

In
the presentation we will also show, how this unique pathway self-regulates the
particle size and offers a totally new strategy to produce spherical shaped curcumin
particle with remarkably high external surface area with  faster dissolution kinetics versus the Form I curcumin
crystals.

Figure 1:
Mechanism showing the formation of pure curcumin spherulites
from its impure solutions: (1) curcumin molecules in a highly supersaturated
solution, (2) formation of pure and defect-free nanocrystals, (3) imperfectly
oriented attachment of the nanocrystals through mechanical relaxation of solid/solid
interface and (4) near perfectly oriented attachment of  crystallites via crystallite docking followed
by elimination of a specific solid/solid interface and growth of new fibre like
structures via low angle-branching; also shown is the SEM image of spherulite shaped curcumin crystals.

Literature cited

De Yoreo J J, Gilbert PUPA, Sommerdijk NAJM, Penn RL, Whitelam
S, Joester D, Zhang H, Rimer
JD, Navrotsky A, Banfield
JF, Wallace AF, Michel FM, Meldrum FC, Cölfen H, Dove
PM. Crystallization by particle attachment in synthetic, biogenic, and geologic
environments. Science. 2015; 349(6247): 498-509.

Acknowledgement

This
work was supported by Science Foundation Ireland and is co-funded under the
European Regional Development Fund under Grant Number 12/RC/2275.