Characterisation of
Gliclazide-PEG 8000 Solid Dispersions
S Biswal*, J Sahoo and PN Murthy
Royal College of
Pharmacy and Health Sciences, Andhapasara Road,
Berhampur-760002, Orissa, India.
*Corresponding author:
E-mail:
sudarsan_mpharm@yahoo.co.in Tel:
+91-9437859584 Fax: +91-0680226025
Received: 12 January
2009
Revised accepted: 21 July 2009
Tropical
Journal of Pharmaceutical Research, October 2009; 8(5):
417-424
Abstract
Purpose: The
aim of the present study was to characterise gliclazide
solid dispersions (SDs) prepared with polyethylene
glycol (PEG) 8000 and compare them with SDs in PEG 6000.
Methods:
Gliclazide SDs containing varying concentrations of PEG
8000 were prepared using the fusion – solvent technique,
and their phase solubility behavior and dissolution in
0.1N HCl were assessed at 37 oC. The physical
state of, and gliclazide-PEG interactions in, SDs and
physical mixtures prepared in ratios of 1:1, 1:2 and 1:5
(gliclazide: PEG 8000), respectively, were characterized
by x-ray diffraction (XRD), Fourier-transform infrared (FTIR)
spectroscopy and differential scanning calorimetry
(DSC).
Results: The
solubility of gliclazide increased with increasing
amount of PEG 8000 in aqueous medium. Gibbs free energy
(ΔGotr) values were all negative,
indicating the spontaneous nature of gliclazide
solubilisation. Dissolution studies indicated a
significant increase in the dissolution of gliclazide
when dispersed in PEG 8000. FTIR analysis demonstrated
the absence of well-defined gliclazide - PEG 8000
chemical interaction while DSC and XRD studies indicated
the amorphous /microcrystalline state of gliclazide in
the SDs.
Conclusion: In
both solid dispersions and physical mixture, PEG 8000
increases the solubility and dissolution rate of
gliclazide. The increased dissolution rate of gliclazide
may be due to the formation of microcrystals, increased
wettability and dispersibility in systems containing PEG
8000.
Keywords:
Gliclazide, Solid dispersion, PEG 8000, Dissolution,
Solubility, X-ray diffraction, FT-IR, DSC
