The effect of β-cyclodextrins on the permeation of diclofenac from supersaturated solutions

Dias, M

doi:10.1016/s0378-5173(03)00366-1

Cited by 45 publications

(24 citation statements)

References 23 publications

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“…These results confirm that β-CDs do not interact significantly with the silicone membrane. 26 Moreover, although drug diffusion was very similar for all the freeze-dried products, DCF diffusion rate slightly decreased as the CD amount increased. This behavior is the consequence of different drug thermodynamic activity in the studied systems.…”

Section: Diffusion Studiesmentioning

confidence: 93%

“…Similar results were recently reported by different authors. 26,27 As shown in Figure 8, the diffusion profile obtained from the saturated solution is very irregular (R 2 = 0.9589) with high standard deviations. This is a consequence of the higher instability of this system when compared with the DCF-β-CD binary products, which gave a very regular DCF diffusion profile (always R 2 9 0.995) with standard deviation less than 4%.…”

Section: Diffusion Studiesmentioning

confidence: 94%

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

et al. 2005

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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.

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Section: Diffusion Studiesmentioning

confidence: 93%

Section: Diffusion Studiesmentioning

confidence: 94%

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

et al. 2005

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“…In addition, CD can increase the solvation effect of the drug molecules in the solution and can increase the activation energy of the desolvation effect in the process of crystal growth (87,89). Finally, cyclodextrin can act as a kosmotrope (order-maker), which is the non-inclusion mechanism, therefore leading to an increased concentration of free drug and uptake accordingly (94). This process could explain why the value of the equilibrium constant for complex formation is sometimes concentration-dependent and why their numerical value is frequently dependent on the method applied (95).…”

Section: Non-inclusion Complexes Of Cyclodextrinsmentioning

confidence: 99%

“…This process could explain why the value of the equilibrium constant for complex formation is sometimes concentration-dependent and why their numerical value is frequently dependent on the method applied (95). This precipitation inhibition effect can be applied to improve bioavailability in vivo (94).…”

Section: Non-inclusion Complexes Of Cyclodextrinsmentioning

confidence: 99%

Bioavailability Improvement Strategies for Poorly Water-Soluble Drugs Based on the Supersaturation Mechanism: An Update

Yang¹,

Gong²,

Wang³

et al. 2016

J Pharm Pharm Sci

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-The formulation development for poorly soluble drugs still remains a challenge. Supersaturating drug delivery systems (SDDS) or drug delivery systems based on supersaturating provide a promising way to improve the oral bioavailability of poorly water-soluble drugs. In supersaturable formulations, drug concentration exceeds the equilibrium solubility when exposed to gastrointestinal fluids, and the supersaturation state is maintained long enough to be absorbed, resulting in compromised bioavailability. In this article, the mechanism of generating and maintaining supersaturation and the evaluation methods of supersaturation assays are discussed. Recent advances in different drug delivery systems based on supersaturating are the focus and are discussed in detail.

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“…Many studies have reported increases in drug flux 5 to 10 times that of supersaturated solutions (75,81). A study by…”

Section: Supersaturationmentioning

confidence: 99%

Targeted skin delivery of topically applied drugs by optimised formulation design

Abd¹

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Early research concentrated on the relationship between a solute's physicochemical properties and its skin permeation, mostly from simple solutions. Relatively less is known about how vehicles, particularly complex ones, might also affect skin permeation by altering the properties of the skin, although this is an area that has attracted much interest. Key requirements for topical delivery is understanding the relationships between drug-vehicle, drug-skin or drug -vehicle -skin interaction. In this project, understanding this relationship was crucial to designing novel formulations able to deliver drugs with different lipophilicity topically or systemically. The first aim was to explore the impact of various solution compositions on skin permeation of some model drugs. I compared in vitro maximum penetration fluxes (Jmax) and solubilities of the vehicles (Sv) and of the stratum corneum (SSC) and derived diffusivities (D*) for four drugs (caffeine, minoxidil, lidocaine and naproxen) having a range of lipophilicities. I used a range of solvent vehicles that were hypothesised to affect the skin to differing degrees to evaluate vehicle effects on permeability parameters.If neither the vehicle nor the solute alters the properties of the skin, maximum (or saturated) solute flux is independent of both the vehicle composition and the solute's saturated solubility in that vehicle. These findings were confirmed in this study for all four drugs used.The permeation of caffeine, minoxidil, lidocaine and naproxen were found to be selectively enhanced by vehicles containing specific excipients that were hypothesised to alter the properties of the skin. The greatest effects were seen on flux and diffusivity by the eucalyptol (EU) and oleic acid (OA) vehicles on the more hydrophilic compounds, caffeine and minoxidil. We concluded that enhanced solute fluxes were mainly driven by increased diffusivity in the stratum corneum.I also examined the extent of skin permeation enhancement of the hydrophilic drug caffeine and lipophilic drug naproxen applied in nanoemulsions incorporating skin penetration enhancers. Infinite doses of fully characterised oil-in-water nanoemulsions containing the skin penetration enhancers oleic acid or eucalyptol as oil phases and caffeine (3%) or naproxen (2%) were applied to full-thickness skin and human epidermal membranes in Franz diffusion cells, along with aqueous control solutions. Caffeine and naproxen fluxes were determined over 8 h. Solute solubility in the formulations and in the stratum corneum, as well as the uptake of product components into the stratum corneum were measured.The nanoemulsions significantly enhanced the skin penetration of caffeine and naproxen compared to aqueous control solutions. The maximum flux enhancement of caffeine was III associated with a synergistic increase in both its solubility in the stratum corneum and skin diffusivity. Enhanced skin penetration in these systems is largely driven by uptake of formulation excipients containing the active compounds into th...

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The effect of β-cyclodextrins on the permeation of diclofenac from supersaturated solutions

Cited by 45 publications

References 23 publications

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

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

Bioavailability Improvement Strategies for Poorly Water-Soluble Drugs Based on the Supersaturation Mechanism: An Update

Targeted skin delivery of topically applied drugs by optimised formulation design

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