Diclofenac-β-cyclodextrin binary systems: Physicochemical characterization and in vitro dissolution and diffusion studies

Abstract

The aim of this work was to study the influence of β-cyclodextrin (β-CD) on the biopharmaceutic properties of diclofenac (DCF). To this purpose the physicochemical characterization of diclofenac-β-cyclodextrin binary systems was performed both in solution and solid state. Solid phase characterization was performed using differential scanning calorimetry (DSC), powder x-ray diffractometry (XRD), and Fourier transform infrared spectroscopy (FTIR). Phase solubility analyses, and in vitro permeation experiments through a synthetic membrane were performed in solution. Moreover, DCF/β-CD interactions were studied in DMSO by 1 H nuclear magnetic resonance (NMR) spectroscopy. The effects of different preparation methods and drug-to-β-CD molar ratios were also evaluated. Phase solubility studies revealed 1:1 M complexation of DCF when the freeze-drying method was used for the preparation of the binary system. The true inclusion for the freeze-dried binary system was confirmed by 1 H NMR spectroscopy, DSC, powder XRD, and IR studies. The dissolution study revealed that the drug dissolution rate was improved by the presence of CDs and the highest and promptest release was obtained with the freeze-dried binary system. Diffusion experiments through a silicone membrane showed that DCF diffusion was higher from the saturated drug solution (control) than the freeze-dried inclusion complexes, prepared using different DCF-β-CD molar ratios. However, the presence of the inclusion complex was able to stabilize the system giving rise to a more regular diffusion profile.

Comparative assessment of effectiveness of ketoprofen and ketoprofen/beta-cyclodextrin complex in two experimental models of inflammation in rats

“…Enhancement of API release increases absorption by improving bioavailability. 40,41 This was confirmed in the present studies, which showed that K/ b-CD had a higher efficiency than the noncomplexed API. The anti-inflammatory and analgesic effects of the complex were significantly higher and occurred faster, even at low dose rates (15 mg/m 2 body surface), in both types of experimental inflammation.…”

Carvedilol-?-cyclodextrin Systems: Preparation, Characterization and in vitro Evaluation

“…[1][2][3] They have been widely used as complexing agents to modify drug solubility or improve drug stability, and bioavailability, by means of drug inclusion into the hydrophobic cavity of cyclodextrin. CDs are thus offering new hope to formulation scientists in their efforts to develop an effective drug delivery system.…”

Statins therapy: a review on conventional and novel formulation approaches

“…In an aqueous solution, the complexes get readily dissociated, and the free drug molecules are in relatively rapid dynamic equilibrium with drug molecules bound within the CD cavity. [45][46][47] These non-covalent complexes show new physicochemical characteristics when compared with the guest molecules, including better stability, higher aqueous solubility, increased bioavailability and fewer undesirable side effects. [48] Therefore, if it is possible to form statin-CD inclusion complexes and control their solubility, it should be possible to control their drug-release properties.…”