fenugreek gum solution decreases with an increase in alkaline environment (Doyle
et al. 2009). It was proposed that there could be two reasons for this effect,
(a) increment in negative charge along the polymer chains eradicate the hyper
entanglement and (b) association between charged chain continues due to enhance
ionic strength. However, viscosity of the fenugreek solution is recovered by neutralizing the solution with the addition of salt (Doyle et al. 2009). Previously, flow
behaviour of fenugreek gum as a function of concentration and shear rate was
examined and it was observed that the shear thinning behaviour was present in all
concentration ranges demonstrating pseudoplastic behaviour (Wei et al. 2015). At
low shear rates and concentration (<1%, w/v) the apparent viscosity displayed
narrow range newtonian plateau as concentration of fenugreek gum increased, while
newtonian plateau disappeared at 1% (w/v) concentration (Wei et al. 2015).
Pseudoplastic behaviour of fenugreek gum explains the existence of interlacing
molecular interaction between polymer chains (Wei et al. 2015). Galactomannan
exhibits coiled conformation at small shear rates and high apparent viscosity may
induce the interlocking between these coiled complexed macromolecules (Singh
et al. 2009). Deformation in interlocking conformation of complexes due to shear
rate induction leads to decline in solution viscosity (Wei et al. 2015; Jian et al.
2014). Shear strain also changes the orientation of galactomannan to an aligned
fashion, which may reduce the viscosity of solution (Adeli et al. 2015). Fenugreek
gum solution at high concentration display elastic behaviour as the thixotropic
property enhances with an increment in polymer concentration (Wei et al. 2015).
Numerous physical properties of fenugreek gum make it as an ideal excipient to
be used in pharmaceutical industries such as viscosity of fenugreek gum changes
with time, which affects the release profiles of loaded therapeutic agents (Jiang et al.
2007; Lee et al. 2009). Viscosity of fenugreek gum also varies with pH, which gives
it the pharmacological efficacy to be applied in vaginal and ophthalmic drug
delivery (Doyle et al. 2009; Lee et al. 2009).
Thixotropic property of polymer has a vital impact on the therapeutic efficacy of
the formulations by affecting their retention time at the administered site and
enhancing the bioavailability. Thixotropic behaviour of fenugreek gum at higher
concentration might enhance its ability to be used as a smart excipient for numerous
formulations such as ointment, hydrogel, emulsions and suspensions through different routes like oral, topical, ophthalmic and mucosal (Lee et al. 2009).
Smart sun screen formulations must have the pseudoplastic behaviour so that
they can form coherent protective layer over screen to eradicate the hazardous effect
of UV light (Lee et al. 2009). Pseudoplastic behaviour of fenugreek gum at all
concentration range makes it a cost effective candidate to develop sunscreen lotions
(Wei et al. 2015). These rheological properties make fenugreek gum as flexible and
cost effective excipient for various pharmaceutical formulations.
11 Pharmaceutical and Therapeutic Applications of Fenugreek Gum
385
et al. 2009). It was proposed that there could be two reasons for this effect,
(a) increment in negative charge along the polymer chains eradicate the hyper
entanglement and (b) association between charged chain continues due to enhance
ionic strength. However, viscosity of the fenugreek solution is recovered by neutralizing the solution with the addition of salt (Doyle et al. 2009). Previously, flow
behaviour of fenugreek gum as a function of concentration and shear rate was
examined and it was observed that the shear thinning behaviour was present in all
concentration ranges demonstrating pseudoplastic behaviour (Wei et al. 2015). At
low shear rates and concentration (<1%, w/v) the apparent viscosity displayed
narrow range newtonian plateau as concentration of fenugreek gum increased, while
newtonian plateau disappeared at 1% (w/v) concentration (Wei et al. 2015).
Pseudoplastic behaviour of fenugreek gum explains the existence of interlacing
molecular interaction between polymer chains (Wei et al. 2015). Galactomannan
exhibits coiled conformation at small shear rates and high apparent viscosity may
induce the interlocking between these coiled complexed macromolecules (Singh
et al. 2009). Deformation in interlocking conformation of complexes due to shear
rate induction leads to decline in solution viscosity (Wei et al. 2015; Jian et al.
2014). Shear strain also changes the orientation of galactomannan to an aligned
fashion, which may reduce the viscosity of solution (Adeli et al. 2015). Fenugreek
gum solution at high concentration display elastic behaviour as the thixotropic
property enhances with an increment in polymer concentration (Wei et al. 2015).
Numerous physical properties of fenugreek gum make it as an ideal excipient to
be used in pharmaceutical industries such as viscosity of fenugreek gum changes
with time, which affects the release profiles of loaded therapeutic agents (Jiang et al.
2007; Lee et al. 2009). Viscosity of fenugreek gum also varies with pH, which gives
it the pharmacological efficacy to be applied in vaginal and ophthalmic drug
delivery (Doyle et al. 2009; Lee et al. 2009).
Thixotropic property of polymer has a vital impact on the therapeutic efficacy of
the formulations by affecting their retention time at the administered site and
enhancing the bioavailability. Thixotropic behaviour of fenugreek gum at higher
concentration might enhance its ability to be used as a smart excipient for numerous
formulations such as ointment, hydrogel, emulsions and suspensions through different routes like oral, topical, ophthalmic and mucosal (Lee et al. 2009).
Smart sun screen formulations must have the pseudoplastic behaviour so that
they can form coherent protective layer over screen to eradicate the hazardous effect
of UV light (Lee et al. 2009). Pseudoplastic behaviour of fenugreek gum at all
concentration range makes it a cost effective candidate to develop sunscreen lotions
(Wei et al. 2015). These rheological properties make fenugreek gum as flexible and
cost effective excipient for various pharmaceutical formulations.
11 Pharmaceutical and Therapeutic Applications of Fenugreek Gum
385