Limits...
Preparation of SLN-containing Thermoresponsive In-situ Forming Gel as a Controlled Nanoparticle Delivery System and Investigating its Rheological, Thermal and Erosion Behavior.

Dorraj G, Moghimi HR - Iran J Pharm Res (2015)

Bottom Line: Due to their rapid clearance from systemic circulation, nanoparticles do not provide sustained action in most cases.However, gelling kinetic did not change significantly after addition of SLN.Present results indicate potential of sol-gel systems for controlled nanoparticle delivery and show that SLN affects properties of the system.

View Article: PubMed Central - PubMed

Affiliation: Department of Pharmaceutics and Nanotechnology, School of Pharmacy, Shahid Beheshti University of Medical Sciences, Tehran, Iran.

ABSTRACT
Various nanoparticles have been investigated as novel drug delivery systems, including solid lipid nanoparticles (SLNs). Due to their rapid clearance from systemic circulation, nanoparticles do not provide sustained action in most cases. Different strategies have been employed to overcome this problem. In this direction, the present study introduces erodible in-situ forming gel systems as potential vehicles for prolonged release of SLNs. SLNs were prepared by solidification of an oil-in-water microemulsion containing stearic acid, surfactants and co-surfactants. Nanoparticles were then dispersed in a thermosensitive Poloxamer 407 aqueous solution (sol) at 4 °C and their effects on gel forming ability, sol-gel transition and rheological behavior of the system were investigated over 5-50 °C. Thermal behavior of the system was investigated by differential scanning calorimetry too. Erosion rate of the gel in the presence and absence of SLN was measured by gravimetric method. Integrity of SLNs in the system was investigated by scanning electron microscopy (SEM) and particle size analysis. SLN showed particle size and zeta potential of 130 ± 1.39 nm and - 44 ± 2.1 mV respectively. Particle size analysis and SEM studies after gel erosion revealed presence of intact SLN in the hydrogel. SLN reduced erosion rate of Poloxamer gel and increased its sol-gel transition temperature from 26 to 29 °C. However, gelling kinetic did not change significantly after addition of SLN. Damping factor <1 indicated stability of the SLN-containing system. Present results indicate potential of sol-gel systems for controlled nanoparticle delivery and show that SLN affects properties of the system.

No MeSH data available.


Related in: MedlinePlus

Temperature dependency of the dynamic moduli, G" and G' of a freshly prepared 20% (w/v) Poloxamer 407 solution.
© Copyright Policy
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4403051&req=5

Figure 6: Temperature dependency of the dynamic moduli, G" and G' of a freshly prepared 20% (w/v) Poloxamer 407 solution.

Mentions: Figure 6 and Figure 7show the profile of oscillatory parameters versus temperature for plain Poloxamer and SLN-included Poloxamer systems respectively. This profile shows three distinct phases of sol, gel, gel stabilization; designated as phases I, II and III here. In phase I, that is prior to the gelling point, the elastic modulus, G', shows low values and the samples are characterized as a viscous sol system with higher G". In the second phase and at gelling temperature (phase II), drastic increase in elastic modulus, G', was observed indicating formation of gels with elastic behavior. Figures 6 and 7 show that while G' is lower than G" in phases I and II, it becomes higher than G" in later stages of phase II and phase III. G'>G" is said to be indicator of a well-built structure of a soft gel, possibly due to physical entanglements of polymeric chains (47). Final phase (phase 3) states the stabilization of the elastic modulus, G', above the transition temperature.


Preparation of SLN-containing Thermoresponsive In-situ Forming Gel as a Controlled Nanoparticle Delivery System and Investigating its Rheological, Thermal and Erosion Behavior.

Dorraj G, Moghimi HR - Iran J Pharm Res (2015)

Temperature dependency of the dynamic moduli, G" and G' of a freshly prepared 20% (w/v) Poloxamer 407 solution.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4403051&req=5

Figure 6: Temperature dependency of the dynamic moduli, G" and G' of a freshly prepared 20% (w/v) Poloxamer 407 solution.
Mentions: Figure 6 and Figure 7show the profile of oscillatory parameters versus temperature for plain Poloxamer and SLN-included Poloxamer systems respectively. This profile shows three distinct phases of sol, gel, gel stabilization; designated as phases I, II and III here. In phase I, that is prior to the gelling point, the elastic modulus, G', shows low values and the samples are characterized as a viscous sol system with higher G". In the second phase and at gelling temperature (phase II), drastic increase in elastic modulus, G', was observed indicating formation of gels with elastic behavior. Figures 6 and 7 show that while G' is lower than G" in phases I and II, it becomes higher than G" in later stages of phase II and phase III. G'>G" is said to be indicator of a well-built structure of a soft gel, possibly due to physical entanglements of polymeric chains (47). Final phase (phase 3) states the stabilization of the elastic modulus, G', above the transition temperature.

Bottom Line: Due to their rapid clearance from systemic circulation, nanoparticles do not provide sustained action in most cases.However, gelling kinetic did not change significantly after addition of SLN.Present results indicate potential of sol-gel systems for controlled nanoparticle delivery and show that SLN affects properties of the system.

View Article: PubMed Central - PubMed

Affiliation: Department of Pharmaceutics and Nanotechnology, School of Pharmacy, Shahid Beheshti University of Medical Sciences, Tehran, Iran.

ABSTRACT
Various nanoparticles have been investigated as novel drug delivery systems, including solid lipid nanoparticles (SLNs). Due to their rapid clearance from systemic circulation, nanoparticles do not provide sustained action in most cases. Different strategies have been employed to overcome this problem. In this direction, the present study introduces erodible in-situ forming gel systems as potential vehicles for prolonged release of SLNs. SLNs were prepared by solidification of an oil-in-water microemulsion containing stearic acid, surfactants and co-surfactants. Nanoparticles were then dispersed in a thermosensitive Poloxamer 407 aqueous solution (sol) at 4 °C and their effects on gel forming ability, sol-gel transition and rheological behavior of the system were investigated over 5-50 °C. Thermal behavior of the system was investigated by differential scanning calorimetry too. Erosion rate of the gel in the presence and absence of SLN was measured by gravimetric method. Integrity of SLNs in the system was investigated by scanning electron microscopy (SEM) and particle size analysis. SLN showed particle size and zeta potential of 130 ± 1.39 nm and - 44 ± 2.1 mV respectively. Particle size analysis and SEM studies after gel erosion revealed presence of intact SLN in the hydrogel. SLN reduced erosion rate of Poloxamer gel and increased its sol-gel transition temperature from 26 to 29 °C. However, gelling kinetic did not change significantly after addition of SLN. Damping factor <1 indicated stability of the SLN-containing system. Present results indicate potential of sol-gel systems for controlled nanoparticle delivery and show that SLN affects properties of the system.

No MeSH data available.


Related in: MedlinePlus