CURCUMIN NANOCRYSTAL FOR ORAL ADMINISTRATION:

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CURCUMIN NANOCRYSTAL FOR ORAL ADMINISTRATION
PREPARATION, CHARACTERIZATION AND ELECTROLYTES
STABILITY
Heni Rachmawatia,b, Loaye Al Shaalb, Cornelia
M.Keckb
aPharmaceutics Research Group, School of
Pharmacy, Bandung Institute of Technology,
Ganesha 10 Bandung 40132, Indonesia bFreie
Universität Berlin, Department of Pharmacy,
Pharmaceutical Technology, Biopharmaceutics
NutriCosmetics, Berlin, Germany Email
h_rachmawati_at_fa.itb.ac.id
INTRODUCTION
RESULTS
DISCUSSION
Curcumin, a naturally occuring polyphenolic
phytoconstituent, is isolated from the rhizomes
of Curcuma longa Linn. (Zingiberaceae). It is
insoluble in water under acidic or neutral
conditions but dissolves in alkaline environment.
Curcumin is highly unstable undergoing rapid
hydrolytic degradation in neutral or alkaline
conditions to feruloyl methane and ferulic acid.
It is reported to be stable below pH 6.0. Thus,
the use of curcumin is limited by its poor
aqueous solubility in acidic or neutral
conditions and instability in alkaline pH. It has
anti-cancer, anti-oxidant, anti-inflammatory,
hyperlipidemic, anti bacterial, wound healing and
hepatoprotective activities. The pharmacological
efficacy of curcumin makes it a potential
compound for treatment and prevention of a wide
variety of human diseases. In addition, it is
extremely safe upon oral administration even at
very high doses, as proven in various animal
models or human studies. In spite of this,
curcumin has not yet been approved as a
therapeutic agent, and the relative
bioavailability of curcumin has been highlighted
as a major problem for this.
1. Particle size (LD) vs homogenization cycles
Figure 2 shows the different successful
nanocrystal production, seems to be stabilizer
dependent. Steric stabilization provided by
TPGS, PVP and PVA is suggested to be more
efficient in which the smaller the molecular
weight the more efficient to produce and to
stabilize the nanocrystal. The potential
stabilizing of the five different investigated
stabilizers was confirmed by short-term stability
data (fig. 3 and 4). PVA, PVP, and TPGS preserved
the particle agglomeration at both temperature
over 30 days, while SDS and Na-CMC failed to do
so. The zeta potential values (table 1) is useful
to explain that phenomenon. Particle
agglomeration in SDS-stabilized nanosuspension
(fig. 4) was undetected in the LD measurement
(fig. 3). This can be explained that the
agglomerates were loose and de-aggregated during
LD measurement by stirring mechanism. The
agglomerates formed in Na-CMC-stabilized
nanosuspension was harder and therefore these
size increases were clearly exerted (fig.3)
Figure 2. Particle size reduction (LD data
presented as d95 and d99) as a function of
homogenization cycles for the five different
Curcumin nanosuspensions.
2. Short-term physical stability data
Table.1. Zeta potential of the five differently
stabilized Curcumin nanosuspensions left
analyzes in water (conductivity 50 mS/cm, pH
5.8) right analyzed in the original dispersion
medium.
Stabilizer in water (mV) in original dispersion medium (mV)
PVA -5.53 -2.32
PVP -15.87 -11.93
TPGS -12.45 -15.87
SDS -30.57 -52.23
Na-CMC -26.6 -37.7
Figure 1. Chemical structure of Curcumin
Several approaches to enhance the solubility of
Curcumin such as chemical derivatisation,
complexation or interaction with macromolecules
e.g. gelatin, polysaccharides, protein, and
cyclodextrin have been reported but not
successful yet in practical utility. AIM OF
STUDY To develop Curcumin nanocrystal as an
innovative solution to overcome the oral
biovailability problem of Curcumin.
Figure 5 and 6 show the influence of electrolytes
on the physical stability of all nanosuspensions.
These data again confirm that SDS and
Na-CMC-stabilized nanosuspensions (electrostatic
stabilization) are more sensitive against
electrolytes, particularly to CaCl2 and SGF (low
pH). When the electrolytes were added, the
potential subsequently dropped faster and the
diffuse layer was thinner, leading to the
decrease of zeta potential (data not shown)
therefore reduced the nanosuspension stability.
The agglomeration of nanosuspension with Na-CMC
was loose hence the change in d99 was
undetected, while this destabilization was
obviously appeared in polarized micrograph. In
addition to electrostatic stabilization, polymer
chain of Na-CMC provides a steric protection as
well. This explains why the influence of
electrolytes on the destabilization was moderate
as compared to SDS-stabilized nanosuspension.
Figure 3. Stability profile of five differently
stabilized Curcumin nanosuspensions as function
of days (0-30) stored at room temperature (RT,
left) and 4oC (right).
METHODS

• 1. Preparation of nanosuspensions
• High-pressure homogenization (HPH), Micron Lab 40
  (APV Deutchland GmbH, Germany) was used to
  produce nanosuspension. Five different
  stabilizers polyvinyl alcohol (PVA),
  polyvinylpyrolidone (PVP), D-a-tocopherol
  polyethylene glycol 1000 succinate (TPGS),
  carboxymethylcellulose sodium salt (Na-CMC) and
  sodium dodecyl sulphate (SDS) were used. The
  homogenization process was applied for 2 cycles
  of 300, 500, 1000 bar as pre-milling step and
  continued with applying high pressure at 1500 bar
  for 20 cycles.
• Measurements
• Particle size distribution LD (Laser
  Diffractometry)
• Particle charge zeta potential
• 2. Short-term stability study on the
  nanosuspensions
• All nanosuspensions were stored in sealed vials
  at different temperatures (room temperature, RT
  and 4oC) for 30 days. Samples were taken on day 0
  (day of production), day 7, and day 30.
  Characterizations were carried out including
  analysis of particle size (PCS) and polarized
  light microscopy.
• 3. Electrolytes challenge on the nanosuspensions
• Electrolytes (CaCl2 150 mM, simulated gastric
  fluid (SGF, pH 1.2), and simulated intestinal
  fluid (SIF, pH 6.8)) were admixed to the
  nanosuspensions with the ratio of
  electrolytenanosuspension 13. The physical
  stability of the nanosuspensions were examined at
  0, 30, 60, 120, and 240 minutes after incubation
  with the electrolyte. LD, zeta potential,
  microscopic analysis as well as visual
  observation were performed to monitor the
  stability of the nanosuspensions.

Figure 4. Polarized light micrograph
(magnification 160x) of the nanosuspensions after
7 and 30 days storage at RT. Nanosuspension
stabilized with non ionic polymers (PVA, PVP,
TPGS) are stable with no agglomeration detected,
in contrast with ionic stabilized nanosuspensions
(SDS and Na-CMC). D days
3. Electrolytes destabilization
Figure 6. Polarized light micrograph
(magnification 160x) of the nanosuspensions after
incubation with the electrolytes. Nanosuspension
stabilized with non ionic polymers (PVA, PVP,
TPGS) are stable with no agglomeration detected,
in contrast with ionic stabilized nanosuspensions
(SDS and Na-CMC).
CONCLUSION
Nanocrystal of Curcumin was successfully produced
with four stabilizers PVA, PVP, TPGS, and SDS
with the particle size in the range of 500-700
nm. Na-CMC resulted in slightly larger PCS
diameter (about 800 nm) indicating that this
polymer is not able to efficiently stabilize the
produced crystals at the end of the
homogenization process. PVA, PVP and TPGS showed
similar performance in preserving the Curcumin
nanosuspension stability, including their
potential to maintain physical stability of
Curcumin nanosuspensions against electrolytes
presence in the gastrointestinal tract. In
contrast, SDS and Na-CMC was not successful
stabilizer in this study. Curcumin nanocrystal
seems to be a promising approach to improve oral
bioavailability of this potential natural product
to the forefront of therapeutic agents for
treatment of human diseases.
Figure 5. Change in size d99 of five different
nanosuspensions after addition of CaCl2 (left),
simulated gastric fluid (SGF, middle) and
simulated intestinal fluid (SIF, right).
Measurements were performed as a function of time.
This project was financially supported by DAAD,
under scheme of Indonesian-German Scientists
Exchange Program.
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ONGOING PROJECTS (Dr. Heni Rachmawati)

• Pharmacokinetic, biodistribution and activity
  studies
• Of curcumin nanocrystals vs curcumin
• Join project between school of pharmacy itb
  indonesia and fu berlin germany, supported by itb
  research grant

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• Join project between school of pharmacy itb
  indonesia and national university of singapore,
  supported by islamic development bank

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