Acta Pharm. 57
(2007) 173-184
Original research paper
Spherical crystals of celecoxib
to improve solubility, dissolution rate and micromeritic
properties
VENKADARI
RAMMOHAN GUPTA1*, SRINIVAS MUTALIK2, MADHOBHAI M. PATEL3 and GIRISH K. JANI4
vrmgupta_05@yahoo.co.in
1Department
of Pharmaceutics, N.E.T. Pharmacy College, Navodaya Nagar, Mantralayam Road,
Raichur-584103, India
2 Department of Pharmaceutics, Manipal
College of Pharmaceutical Sciences, Manipal-576104, India
3 Vice Chancellor,
Hemachandracharya North Gujarat University, Patan, India
4 Department of Pharmaceutics, L. M. College of Pharmacy, Navrangpura, Ahmedabad,
India
Accepted January 31, 2007
Celecoxib
spherical agglomerates were prepared with polyvinylpyrrolidone
(PVP) using acetone, water and chloroform as solvent, non-solvent and bridging
liquid, respectively. The agglomerates were characterized by differential
scanning calorimetry (DSC), X-ray diffraction (XRD),
IR spectroscopic studies and scanning electron microscopy (SEM). The IR
spectroscopy and DSC results indicated the absence of any interactions between
drug and additives. XRD studies showed a decrease in crystallinity
in agglomerates. The crystals exhibited significantly improved micromeritic properties compared to pure drug. The loading
efficiency (% or mg drug per 100 mg crystals) was in the range of 93.9 ± 2.3
and 97.3 ± 1.3% (n = 3), with all
formulations. The aqueous solubility and dissolution rate of the drug from
crystals was significantly (p <
0.05) increased (nearly two times). The solubility and in vitro drug release rates increased with an increase in PVP
concentration (from 2.5 to 10%). The SEM
studies showed that the crystal possesses a good spherical shape with smooth
and regular surface.
Keywords: celecoxib, spherical
crystallization, solubility, dissolution rate, micromeritic properties