Influence of cyclodextrin complexation on piroxicam gel formulations

Department of Pharmaceutics Faculty of Pharmacy and Biochemistry University of Zagreb, Zagreb, Croatia.
Acta Pharmaceutica (Impact Factor: 0.91). 10/2005; 55(3):223-36.
Source: PubMed


The aim of this work was to evaluate the role of cyclodextrins in topical drug formulations. Solid piroxicam (PX) complexes with beta-cyclodextrin (beta-CD) and randomly methylated beta-cyclodextrin (RAMEB) were prepared by freeze-drying and characterized using differential scanning calorimetry (DSC), X-ray powder diffractometry (XRPD), Fourier transform infrared spectroscopy (FTIR) and near infrared spectroscopy (NIR). A physical mixture of PX and cyclodextrins was characterized by enhanced dissolution properties compared to the dissolution profile of the pure drug due to in situ complex formation. Formation of the PX-cyclodextrin inclusion complex additionally improved the drug dissolution properties. Influence of CDs on drug permeation from the water dispersion and the prepared hydroxypropyl methylcellulose (HPMC) gels was investigated. Permeation of the drug involved three consecutive processes: dissolution of the solid phase, diffusion across the swollen polymer matrix and drug permeation through the membrane. Complexation increased PX diffusion by increasing the amount of diffusible species in the donor phase. Slower drug diffusion through the HPMC matrix was the rate limiting step in the overall diffusion process. Possible interaction between the hydrophilic polymer and cyclodextrin may result in physicochemical changes, especially in a change of rheological parameters.

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    • "In the literature, some information is available on the enhancement of drug release from different topical bases using solid dispersion and inclusion complex techniques [18] [19] [20]. Ketoconazole (KET), an azole antifungal agent, is used to relieve the external symptoms (candidal vulvitis) of vaginal thrush (candidal vaginitis) but it has a poor aqueous solubility making it difficult to dissolve in water [2]. "
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    Indian Journal of Pharmaceutical Sciences 09/2011; 73(5):517-26. DOI:10.4103/0250-474X.98995 · 0.48 Impact Factor
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    • "CDs enhance the solubility of nonpolar substances by non-covalent incorporation of the lipophilic portion of the molecule into their hydrophobic cavity (Bender and Komiyama, 1978).CDs are cyclic oligosaccharides consisting of 6, 7, or 8 glucose units linked through α-1,4-glucosidic bonds yielding α-β-, and γ-CD, respectively. They have been used to as carrier to deliver hydrophobic substances including long-and short-chain fatty acids, hormones, and drugs (Vicanova et al., 1999;Biddy et al., 2000;Pfitzner et al., 2000;Ulloth et al., 2003;Loftsson et al., 2006;Cappello et al., 2006;Miro et al., 2004;Jug et al., 2005). Early studies reported only minimal toxicity for CDs used to deliver lipophilic substances to cells in culture (Keller and Simons, 1998;Epa et al., 2000) as well as in the intrathecal/intracerebral delivery of hydrophobic drugs (Yaksh et al., 1991;Jang et al., 1992;Yamamoto and Yaksh, 1992). "
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