Effect of pH and Hydroxylpropyl-b-Cyclodextrin on Solubility and Stability of
Gliclazide
Bharti D Shewale*1, Ravindra A Fursule1,
Nidhi P Sapkal2
1HR
Patel Women’s College of Pharmacy, Karwand Naka, Tal-
Shiprur, Dist – Dhule - 425405 (M. S.) India.
2Gurunanak
College of Pharmacy, Near Dixit Nagar, Nari,
Nagpur-440024. (M.S.), India.
E-mail:
bhartishewale15@rediffmail.com
Mobile:
+919823606010
Fax:
02563255108
International Journal of Health Research,
June
2008; 1(2):
95-99
Received: 07-Jun-08 Accepted for publication:
19-Jun-08
Short Communication
Abstract
Purpose:
Hydroxy propylated β cyclodextrin (HP-β-CD) has been
used to improve the aqueous solubility of a variety of
pharmacological compounds. Through the complexation of
HP-β-CD, it is possible to enhance the water solubility
and hence the drug bioavailability after oral
administration. The present study was undertaken to
examine the effect of pH and concentration of HP-β-CD on
the solubility of gliclazide as it shows pH dependent
solubility and stability.
Method:
The equilibrium solubility of gliclazide in a series of
solutions of varying pH (from 1.2 to 11) was determined
and compared with the equilibrium solubility of
gliclazide in the presence of 20% HP- β-CD at same pH
values.
Result:
As the pH increases from 9.2 to 11 its solubility
relatively constant (3.5 μg/ml ± 0.5). Addition of 20%
HP-β-CD increased the solubility to about 9 times at pH
1.2 and 4; 15 times at pH 6.8; 40 times at pH 7.4; 58
times at pH 9.2 and 67 times at pH 11. It was observed
that solubility of protonated form is more than neutral
molecule. HP-β-CD resulted in increased solubility at
all pH values. But inclusion of drug in the cavity of
HP-β-CD might depend upon charged state of the molecule.
Conclusion:
The solubility of gliclazide can be increased either by
the addition of HP-β-CD or by adding pH lowering agents.
Keywords:
pH,
hydroxypropylated-β-cyclodextrin (HP-β-CD), gliclazide.
