1706 Int J Pharm Sci Nanotech Vol 5; Issue 2 • July−September 2012 Research Paper Formulation and Evaluation of Gliclazide Tablets Containing PVP-K30 and Hydroxypropyl-β-cyclodextrin Solid Dispersion M. Mohan Varma* and P. Satish Kumar Shri Vishnu College of Pharmacy, Vishnupur, Bhimavaram-534202, Andhra Pradesh, India. Received April 6, 2012; accepted April 30, 2012 ABSTRACT Gliclazide is an anti-diabetic drug. It is a BCS class-II (poorly water soluble) drug and its bioavailability is dissolution rate limited. The dissolution rate of the drug was enhanced by using the solid dispersion technique. Solid dispersions were prepared using PVP-K30 (polyvinylpyrrolidone) and hydroxypropyl-β-cyclodextrin (HP BCD) as the hydrophilic carriers. The solid dispersions were characterized by using DSC (Differential scanning calorimetry), XRD (X-ray diffractometry) and FTIR (Fourier transform infrared spectroscopy). Solid dispersions were formulated into tablets. The formulated tablets were evaluated for the quality control parameters and dissolution rates. The solid-dispersion tablets enhanced the dissolution rate of the poorly soluble drug. The optimized formulation showed a 3 fold faster drug release compared to the branded tablet. The XRD studies demonstrated the remarkable reduction in the crystallinity of the drug in the solid dispersion. The faster dissolution rate of the drug from the solid dispersion is attributed to the marked reduction in the crystallinity of the drug. The DSC and FTIR studies demonstrated the absence of the drug-polymer interaction. KEYWORDS: Gliclazide; solid dispersions; PVP-K30; hydroxypropyl-β-cyclodextrin Introduction One of the areas of current interest in pharmaceutical technology that has had significant impact on clinical therapy is the enhancement of dissolution rate and bioavailability of insoluble and poorly water soluble drugs (Konno et al., 2008; Urbanetz and Lippold, 2005). The poor aqueous solubility and wettability of these drugs gave rise to difficulty in the design of pharmaceutical formulation and leads to variable oral bioavailability (Choiu and Riegelman, 1971). The enhancement of oral bioavailability of poorly soluble drugs remains one of the most challenging aspects of drug development (Batra et al., 2008; Christian and Dressman, 2000). Salt formation, solubilization and size reduction have commonly been used to increase the dissolution rate and, thereby, the oral absorption and bioavailability of such drugs. There are some practical limitations of these techniques. Solid dispersion technology is the science of dispersing one or more active ingredients in an inert matrix in the solid state in order to achieve an increased dissolution rate, sustained release of drugs, altered solid state properties and enhanced bioavailability (Leuner and Dressman, 2000; Sheu et al., 1994). The solid dispersion approach has been widely and successfully applied to improve the solubility, dissolution rate and consequently the bioavailability of poorly soluble drugs (Babu et al., 2002; Craig, 2002; Sudha et al., 2002; Varma and Pandit, 2005). Many hydrophilic excipients like PVP, cyclodextrins, PEG 4000, PEG 6000, mannitol, and poloxamers can be used to enhance the dissolution of poorly soluble drugs (Dahlberga et al., 2010; Weuts et al., 2005). Gliclazide is a second-generation hypoglycemic sulfonylurea used in the treatment of type 2 diabetes mellitus (Betageri and Makarla, 1995; Zkan et al., 2000). It stimulates beta cells of the Islet of Langerhans in the pancreas to release insulin. It also enhances peripheral insulin sensitivity. Overall, it potentiates insulin release and improves insulin dynamics. One of the major problems of gliclazide is its poor aqueous solubility and hence low dissolution rate in water, which results in poor bioavailability after oral administration. Solid dispersions of gliclazide in PEG 6000 have been developed to increase the dissolution rate (Biswal et al., 2008). In the present study, an attempt was made to improve the dissolution rate of the poorly water soluble drug gliclazide by solid dispersion technique using PVP- K30 and hydroxypropyl-β-cyclodextrin (HP-BCD) as the hydrophilic carriers. The solid dispersions were characterized by FTIR, DSC and XRD. The solid dispersions were compressed into fast dissolving tablets and were evaluated for the quality control parameters and the dissolution rate. International Journal of Pharmaceutical Sciences and Nanotechnology Volume 5 • Issue 2• July – September 2012 MS ID: IJPSN-4-6-12-VARMA 1706