Flow and Tableting Behaviors of Some Egyptian Kaolin Powders as Potential Pharmaceutical Excipients

Abstract

The present work aimed at assessing the pharmaceutical tableting properties of some Egyptian kaolin samples belong to the Abu Zenima kaolin deposits (estimated at 120 million tons). Four representative samples were selected based on kaolinite richness and their structural order-disorder degree, and after purification, they were dried at 70 • C and heated from room temperature up to 400 • C (10 • C/min). Mineralogy, micromorphology, microtexture, granulometry, porosimetry, moisture content, bulk and tapped density, direct and indirect flowability, and tableting characteristics are studied. Results indicated that purified kaolin samples were made up of 95-99% kaolinite, <3% illite, 1% quartz and 1% anatase. The powder showed mesoporous character (pore diameters from 2 to 38 nm and total pore volume from 0.064 to 0.136 cm 3 /g) with dominance of fine nanosized particles (<1 µm-10 nm). The powder flow characteristics of both the ordered (Hinckley Index HI > 0.7, crystallite size D001 > 30 nm) and disordered (HI < 0.7, D001 < 30 nm) kaolinite-rich samples have been improved (Hausner ratio between 1.24 and 1.09) as their densities were influenced by thermal treatment (with some observed changes in the kaolinite XRD reflection profiles) and by moisture content (variable between 2.98% and 5.82%). The obtained tablets exhibited hardness between 33 and 44 N only from the dehydrated powders at 400 • C, with elastic recovery (ER) between 21.74% and 25.61%, ejection stress (ES) between 7.85 and 11.45 MPa and tensile fracture stress (TFS) between 1.85 and 2.32 MPa, which are strongly correlated with crystallinity (HI) and flowability (HR) parameters. These findings on quality indicators showed the promising pharmaceutical tabletability of the studied Egyptian kaolin powders and the optimization factors for their manufacturability and compactability.

Enhanced alumina extraction from kaolin by thermochemical activation using charcoal

“…7a). The specific parameters of the particle-size homogeneity (span = ( D 90 – D 10 )/ D 50 ), the uniformity coefficient ( C u = D 60 / D 10 ) and the gradation curvature coefficient ( C c = D 30 2 /( D 60 D 10 )) were calculated (Table 4) (Awad et al , 2018a, 2020). There was no significant correlation between sintering temperature and the particle-size homogeneity of any of the sinters, as the size span values ranged from 2.40 (in the sinter produced under 1260°С) to 4.39 (in the sinter produced under 1300°С), with an average value of 3.33.…”

“…7A). 4, Awad et al, 2018aAwad et al, , 2020. There was no significant correlation between the sintering temperatures and the particle size homogeneity of all the sinters, as the size span values were ranged from 2.40 (in the sinter produced under 1260 °С) to 4.39 (in the sinter produced under 1300 °С) with an average of 3.33.…”

Removal of ivermectin from aqueous media using commercial, bentonite-based organophilic clay as an adsorbent

“…The N2 adsorption/desorption isotherm at 77 K of the clay shown in Fig. 1 approached a type II isotherm, with a predominance of macropores and the presence of mesopores, evidenced by the H3 type hysteresis, which is associated with non-rigid aggregates of plate-shaped particles, resulting in slit pores (Awad et al, 2020). The specific area obtained for the clay was 7 m 2 g -1 (Table 3), and is in accordance with the material attributed to the structure of the organophilic clay.…”

Optimization of Carboniferous Egyptian Kaolin Treatment for Pharmaceutical Applications

“…Their research shows significant differences in the distributions of the major and trace elements among the samples collected from different locations at Abu Zeneima. In addition, the Wadi Abu Natash exposure provided the highest and purest kaolin ore, and the massive kaolin clay beds, especially, are being considered as promising pharmaceutical excipients [5,22]. However, the authors point out that Abu Natash kaolin contains high concentrations of PTEs, especially As, Cr, Cu, Ni, Pb, and V.…”