Micro-Nano formulation of bile-gut delivery: rheological, stability and cell survival, basal and maximum respiration studies

Abstract

Probucol (PB) is a drug that exhibits significant hydrophobicity and substantial intra and inter individual variability in oral absorption, with a miniature bioavailability and complex three compartmental pharmacokinetic modelling due to its high lipid affinity, low stability and high octanol to water partition coefficient. Multiple attempts to formulate PB have not produced satisfactory stable matrices, drug-release profile or rheological flow properties for optimum manufacturing conditions, and with positive and none toxic biological effects. Lithocholic acid (LCA) has recently shown to optimise formulation and cell uptake of drugs. Hence, the aim of this study was to design new PB delivery system, using LCA, and examine its morphology, rheology, stability, and cellular effects. PB was formulated with LCA and sodium alginate (PB-LCA-SA) using various microencapsulation methodologies, and best formulation was investigated in vitro and ex vivo. Using our Ionic Gelation Vibrational Jet flow technology, PB-LCA-SA microcapsules showed good stability and significantly enhanced cell viability, cellular respiration, and reduced inflammation suggesting potential LCA applications in PB delivery and biological effects.

Figure 1

(A) Optical microscopy of PB-SA (i) and PB-LCA-SA (ii) microcapsules. (B)Scanning electron micrographs of PB-SA revealing microcapsules morphology and surface topography took at different magnifications, (i) 100 μm scale (ii) Surface morphology at 10 μm scale. (iii) 2 μm scale (iv) 1 μm scale. (C) Scanning electron micrographs of PB-LCA-SA and surface topography taken at different magnifications, (i) 100 μm scale (ii) Surface morphology at 10 μm scale. (iii) 2 μm scale (iv) 1 μm scale. PB- probucol; SA- sodium alginate; LCA-lithocholic acid.

Figure 2

(A) EDS of PB-SA microcapsules and the corresponding elemental analysis (a-c). (B) EDS of PB-LCA-SA microcapsules and the corresponding elemental analysis (d-f). PB- probucol; SA- sodium alginate; LCA-lithocholic acid.

Figure 3

(A) Effect of shearing stress on viscosities, (B) Effect of speed on shear rate, (C) Dominant peaks observed by DSC analysis. PB- probucol; SA- sodium alginate; LCA-lithocholic acid.

Figure 4

Microencapsules dissolution profiles in simulated gastric media at pH 1.5 (A), pH 3 (B), pH 6 (C) and pH 7.8 (D). N = 3, mean ± SD. PB- probucol; SA- sodium alginate; LCA-lithocholic acid.*p < 0.05.

Figure 5

NIT-1 cell viability at 5.5 mmol and 25 mmol glucose (A), (B–D) NIT-1 level of inflammatory cytokines production, (E–I) bioenergetics parameters for NIT-1 beta cells at 5.5 mmol and 25 mmol glucose treated with PB-SA and PB-LCA-SA microcapsules. PB- probucol; SA- sodium alginate; LCA-lithocholic acid. Data values are mean ± SD, N = 3; p < 0.01.

Figure 6

The summary figure of the study.