Effect of hydroxypropyl β-cyclodextrin on the self-assembling and thermogelation properties of Poloxamer 407

Bonacucina, Giulia; Spina, Michele; Misici‐Falzi, Monica; Cespi, Marco; Pucciarelli, Stefania; Angeletti, Mauro

doi:10.1016/j.ejps.2007.06.004

Cited by 61 publications

(53 citation statements)

References 27 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Assignments of chemical shifts obtained by analyzing the carbon and hydrogen NMR spectra are described in Table 2. The identity of the compound was confirmed by NMR spectra of carbon and hydrogen and infrared spectroscopy (data not shown) and the results are in agreement with the literature (10,43). In addition, these results suggest the absence of contaminating substances, which confirm both the purity of the extracted drug and the effectiveness of the extraction procedure.…”

Section: Lm Extraction From Commercial Tabletssupporting

confidence: 79%

“…The T sol-gel graph was determined by sweeping temperatures as a function of G'. The transition temperature was defined as the point where the elastic modulus was half way between G' for the solution and G'' for the gel (15,43). The results were expressed as averages ± S.D of three experiments (n=3) for each group.…”

Section: Determination Of Gelation Temperaturementioning

confidence: 99%

See 1 more Smart Citation

Influence of Oleic Acid on the Rheology and in Vitro Release of Lumiracoxib from Poloxamer Gels

2010

View full text Add to dashboard Cite

-Purpose. Transdermal delivery of anti-inflammatory lumiracoxib (LM) could be an interesting strategy to avoid the side effects associated with systemic delivery, but it is ineffective due to the drug poor skin penetration. We have investigated the effects of oleic acid (OA), a lipid penetration enhancer, on the in vitro release of LM from poloxamer-based delivery systems (PBDS). The rheological behavior (shear rate dependent viscosity) and gelation temperature through measurements of optimal sol-gel transition temperatures (T sol-gel ) were also carried out in these systems. Methods. In vitro release studies of LM from PBDS were performed using cellulose acetate as artificial membrane mounted in a diffusion system. The amount of LM released was divided by exposition area (µg/cm 2 ) and these values were plotted as function of the time (h). The flux of the drug across the membrane (J) was calculated from the slope of the linear portion of the plot and expressed as µg/cm 2 /h. The determination of viscosity was carried out at different shear rates (γ) between 0.1-1000 S -1 using a parallel plate rheometer. Oscillatory measurements using a cone-plate geometry rheometer surrounded by a double jacket with temperature varying 4-40°C, was used in order to determine T sol-gel . Results. Increase of both polymer and OA concentrations increases the viscosity of the gels and consequently reduces the in vitro LM release from the PBDS, mainly for gels containing OA at 10.0% (w/w) compared to other concentrations of the penetration enhancer. T sol-gel transition temperature was decreased by increasing viscosity; in some cases the formulation was already a gel at room temperature. Rheological studies showed a pseudoplastic behavior, which facilitates the flow and improves the spreading characteristics of the formulations. Conclusions. Taken together, the results showed that poloxamer gels are good potential delivery systems for LM, leading to a sustained release, and also have appropriate rheological characteristics.

show abstract

Section: Lm Extraction From Commercial Tabletssupporting

confidence: 79%

Section: Determination Of Gelation Temperaturementioning

confidence: 99%

Influence of Oleic Acid on the Rheology and in Vitro Release of Lumiracoxib from Poloxamer Gels

2010

View full text Add to dashboard Cite

show abstract

“…This result is in agreement with previously reported data. 57,64,71 The SGT as measured by DSC agreed with those measured with the inverted tube method. Figure 8A also shows an endothermic peak obtained for the pure 16% F127 solution.…”

Section: Thermal Analysis Of Thermo-sensitive F127 Systemsupporting

confidence: 70%

“…In addition, a small shoulder peak representing SGT was found at a higher temperature, which appeared at the right-hand end of the CMT peak, corresponding to micelle rearrangement -a cause of thermogelation and consistent with previous reports. 41,57,71 However, thermogelation is only accompanied by a small enthalpy value; thus, it appears that DSC is less sensitive to the occurrence of the sol-gel transition, but more sensitive to the onset of rapid micelle formation.…”

Section: Thermal Analysis Of Thermo-sensitive F127 Systemmentioning

confidence: 99%

“…At elevated temperatures, these systems show phase transformation due to the complete dehydration of both PO (propylene oxide) and EO (ethylene oxide) blocks. 70,71 Thus the systems are, in general, liquids at low temperature but give rise to a strong gel at a given higher temperature. This process involving phase transformation is defined as "sol-gelation transition".…”

Section: Thermal Analysis Of Thermo-sensitive F127 Systemmentioning

confidence: 99%

See 1 more Smart Citation

Thermoreversible Pluronic® F127-based hydrogel containing liposomes for the controlled delivery of paclitaxel: in vitro drug release, cell cytotoxicity, and uptake studies

Nie¹,

Hsiao²,

Pan³

et al. 2011

IJN

120

View full text Add to dashboard Cite

Purpose To develop an in situ gel system comprising liposome-containing paclitaxel (PTX) dispersed within the thermoreversible gel (Pluronic ® F127 gel) for controlled release and improved antitumor drug efficiency. Methods The dialysis membrane and membrane-less diffusion method were used to investigate the in vitro drug release behavior. Differential scanning calorimetry (DSC) thermal analysis was used to investigate the “micellization” and “sol/gel transition” process of in situ gel systems. In vitro cytotoxicity and drug uptake in KB cancer cells were determined by MTT, intercellular drug concentration, and fluorescence intensity assay. Results The in vitro release experiment performed with a dialysis membrane model showed that the liposomal gel exhibited the longest drug-release period compared with liposome, general gel, and commercial formulation Taxol ® . This effect is presumably due to the increased viscosity of liposomal gel, which has the effect of creating a drug reservoir. Both drug and gel release from the in situ gel system operated under zero-order kinetics and showed a correlation of release of PTX with gel, indicating a predominating release mechanism of the erosion type. Dispersing liposomes into the gel replaced larger gel itself for achieving the same gel dissolution rate. Both the critical micelle temperature and the sol/gel temperature, detected by DSC thermal analysis, were shifted to lower temperatures by adding liposomes. The extent of the shifts depended on the amount of embedded liposomes. MTT assay and drug uptake studies showed that the treatment with PTX-loaded liposomal 18% Pluronic F127 yielded cytotoxicities, intercellular fluorescence intensity, and drug concentration in KB cells much higher than that of conventional liposome, while blank liposomal 18% Pluronic F127 gel was far less than the Cremophor EL ® vehicle and empty liposomes. Conclusions A thermosensitive hydrogel with embedded liposome is a promising carrier for hydrophobic anticancer agents, to be used in parenteral formulations for treating local cancers.

show abstract

Improving material properties of a poloxamer P407 hydrogel‐based hydroxyapatite bone substitute material by adding silica—A comparative in vivo study

Kämmerer,

Heimes,

Zaage

et al. 2024

J Biomed Mater Res

View full text Add to dashboard Cite

The structure and handling properties of a P407 hydrogel‐based bone substitute material (BSM) might be affected by different poloxamer P407 and silicon dioxide (SiO2) concentrations. The study aimed to compare the mechanical properties and biological parameters (bone remodeling, BSM degradation) of a hydroxyapatite: silica (HA)‐based BSM with various P407 hydrogels in vitro and in an in vivo rat model. Rheological analyses for mechanical properties were performed on one BSM with an SiO2‐enriched hydrogel (SPH25) as well on two BSMs with unaltered hydrogels in different gel concentrations (PH25 and PH30). Furthermore, the solubility of all BSMs were tested. In addition, 30 male Wistar rats underwent surgical creation of a well‐defined bone defect in the tibia. Defects were filled randomly with PH30 (n = 15) or SPH25 (n = 15). Animals were sacrificed after 12 (n = 5 each), 21 (n = 5 each), and 63 days (n = 5 each). Histological evaluation and histomorphometrical quantification of new bone formation (NB;%), residual BSM (rBSM;%), and soft tissue (ST;%) was conducted. Rheological tests showed an increased viscosity and lower solubility of SPH when compared with the other hydrogels. Histomorphometric analyses in cancellous bone showed a decrease of ST in PH30 (p = .003) and an increase of NB (PH30: p = .001; SPH: p = .014) over time. A comparison of both BSMs revealed no significant differences. The addition of SiO2 to a P407 hydrogel‐based hydroxyapatite BSM improves its mechanical stability (viscosity, solubility) while showing similar in vivo healing properties compared to PH30. Additionally, the SiO2‐enrichment allows a reduction of poloxamer ratio in the hydrogel without impairing the material properties.

show abstract

Effect of hydroxypropyl β-cyclodextrin on the self-assembling and thermogelation properties of Poloxamer 407

Cited by 61 publications

References 27 publications

Influence of Oleic Acid on the Rheology and in Vitro Release of Lumiracoxib from Poloxamer Gels

Influence of Oleic Acid on the Rheology and in Vitro Release of Lumiracoxib from Poloxamer Gels

Thermoreversible Pluronic® F127-based hydrogel containing liposomes for the controlled delivery of paclitaxel: in vitro drug release, cell cytotoxicity, and uptake studies

Improving material properties of a poloxamer P407 hydrogel‐based hydroxyapatite bone substitute material by adding silica—A comparative in vivo study

Contact Info

Product

Resources

About

Effect of hydroxypropyl β-cyclodextrin on the self-assembling and thermogelation properties of Poloxamer 407

Cited by 61 publications

References 27 publications

Influence of Oleic Acid on the Rheology and in Vitro Release of Lumiracoxib from Poloxamer Gels

Influence of Oleic Acid on the Rheology and in Vitro Release of Lumiracoxib from Poloxamer Gels

Thermoreversible Pluronic&reg; F127-based hydrogel containing liposomes for the controlled delivery of paclitaxel: in vitro drug release, cell cytotoxicity, and uptake studies

Improving material properties of a poloxamer P407 hydrogel‐based hydroxyapatite bone substitute material by adding silica—A comparative in vivo study

Contact Info

Product

Resources

About

Thermoreversible Pluronic® F127-based hydrogel containing liposomes for the controlled delivery of paclitaxel: in vitro drug release, cell cytotoxicity, and uptake studies