Evaluation of gellan gum fluid gels as modified release oral liquids

Abstract

Oral liquids are often preferred for drug administration to patients for whom swallowing is difficult, however formulating modified release versions can be challenging. A potential route to achieve modified release in oral liquids is by using fluid (sheared) gels formed by introducing a shear field during gelation in gel-forming biopolymers. These fluid gels can act as pourable viscoelastic fluids but retain true gel micro/nano structure. Here, we have demonstrated that fluid gels have potential as paediatric oral liquids preventing release of ibuprofen in simulated gastric fluid. Subsequent release at pH 7.4 was affected by the duration of exposure and magnitude of acid pH with a linear relationship between onset of release and the preceding acidic exposure duration. Delayed release was a result of increasing gel stiffness, a consequence of the acidity of the initial release media and exposure time. A much faster release rate was measured when exposure time in acid was 10 min compared with 60 min. This study highlights the potential to design fluid gels that are tuned to have a specified stiffness at a particular pH and exposure time. This could enable the preparation oral liquids with modified release behaviour.

Gellan gum fluid gels for topical administration of diclofenac

“…elastic modulus) and particle size of fluid gel can be changed by changing polymer concentrations (Norton et al, 1999;Mahdi et al, 2014). The results in Figure 1C are in good agreement with the previously reported data as they show that Gʹ decreased with decreasing gellan concentrations.…”

“…In previous studies, the potential use of gellan gum fluid gels in pharmaceutical formulations was presented; these have included an oral liquid formulation (Mahdi et al, 2014) and a nasal spray (Mahdi et al, 2015). Here, the investigation focused on the potential use of gellan gum fluid gels for topical formulations.…”

“…The bulk sample is referred to as a fluid gel or sheared gel, whereby the material behaves as a pourable viscoelastic fluid whilst retaining a cross-linked gel microstructure within the particles. Fluid gels prepared from gellan gum have been previously described (Sworn et al, 1995;Mahdi et al, 2014;Mahdi et al, 2015) and an attractive feature of gellan gum fluid gels is that the physical properties can be easily tuned. This can be achieved by simply changing the concentration of the gellan or by changing the rate of cooling and/or shear rate during fluid gel formation (Mahdi et al, 2014).…”

“…Fluid gels prepared from gellan gum have been previously described (Sworn et al, 1995;Mahdi et al, 2014;Mahdi et al, 2015) and an attractive feature of gellan gum fluid gels is that the physical properties can be easily tuned. This can be achieved by simply changing the concentration of the gellan or by changing the rate of cooling and/or shear rate during fluid gel formation (Mahdi et al, 2014). The mechanical properties of gellan gum fluid gels can also be changed by using blends of LA and HA gellan (Mahdi et al, 2015).…”

Potential Synthetic Biolubricant as an Alternative to Bovine Serum

“…If a shear force is applied to gel forming biopolymers such as gellan gum during the sol-gel transition, the material formed is a suspension of microgel particles which behave in bulk as a pourable viscoelastic fluid. Furthermore the size of the microgel particles can be easily controlled by simply changing the concentration of the polymer or by the rate of cooling and/or shear rate during fluid gel formation [21]. Consequently, such materials have been explored for application within the food and pharmaceutical industries due to their interesting rheological and tribological properties [22][23][24].…”