Microencapsulation as a novel delivery method for the potential antidiabetic drug, Probucol

Figures & data

Figure 1 Probucol microcapsules (A) and sodium alginate microcapsule (B).

Notes: L1 and L2 are vertical diameter and horizontal diameter, and L3, L4, and L5 are membrane width thickness at different positions of the microcapsules, respectively. Probucol manufactured by Sigma-Aldrich Co., St Louis, MO, USA.

Figure 2 Scanning electron micrographs.

Notes: Sodium alginate microcapsule at 200 μm scale (A); surface morphology at 2 μm scale (B), 10 μm scale (C), and 3 μm scale (D).

Figure 3 Scanning electron micrographs.

Notes: Probucol-sodium alginate microcapsule at 200 μm scale (A); surface morphology at 2 μm scale (B), 10 μm scale (C), and at 3 μm scale (D). Probucol manufactured by Sigma-Aldrich Co., St Louis, MO, USA.

Figure 4 Energy-dispersive X-ray spectra of sodium alginate microcapsules’ surface.

Notes: Showing crystal deposition (A, 1) and surface composition (C, 2), with corresponding analysis (B and D). Note that no sulfur atoms were detected because no Probucol was in this formulation.

Figure 5 Energy-dispersive X-ray spectra of Probucol-sodium alginate microcapsules surface.

Notes: Drug deposition (A, 1) and surface composition (C, 2) with corresponding analysis (B and D). The presence of drug crystals and corresponding sulfur atoms detected confirm the presence of Probucol in this formulation. Probucol manufactured by Sigma-Aldrich Co., St Louis, MO, USA.

Table 1 Viscosities and related parameters of both microencapsulated formulations, sodium alginate and Probucol-sodium alginate (n=3)

Formula code and set speed	RPM	Viscosity, mPa × seconds	Shear rate, seconds^−1	Torque, mNm	Shear stress, Pa
Sodium alginate
1	20	UD	23.8±0.2	UD	UD
2	35	UD	42.1±0.5	UD	UD
3	61	UD	74.4±0.3	UD	UD
4	107	UD	125±0.2	UD	UD
5	187	UD	222±0.3	UD	UD
6	327	UD	385.8±0.2	UD	UD
7	572	UD	681.8±0.1	UD	UD
8	1,000	UD	1,197±3	UD	UD
Probucol-sodium alginate
1	20	UD	23.9±0.3	UD	UD
2	35	UD	42.2±0.3	UD	UD
3	61	UD	74.5±0.2	0.08±0.01	UD
4	107	25±0.2	125.1±0.2	0.11±0.01	3.2±0.02
5	187	20±0.2	222.2±0.4	0.17±0.02	4.5±0.01
6	327	15±0.3	385.7±0.3	0.21±0.03	5.7±0.03
7	572	10±0.2	681.8±0.1	0.26±0.02	6.9±0.1
8	1,000	9±0.3	1,194±4	0.40±0.03	10.9±0.01

Note: Probucol manufactured by Sigma-Aldrich Co., St Louis, MO, USA.

Abbreviations: UD, undetected (below the instrument limit of detection); RPM, revolutions per minute.

Figure 6 Differential scanning calorimetric thermograms.

Notes: Probucol powder (A), sodium alginate powder (B), Probucol-sodium alginate microcapsule (C), and Probucol-sodium alginate powder (D). Probucol manufactured by Sigma-Aldrich Co., St Louis, MO, USA.

Figure 7 Fourier transform infrared spectra.

Notes: Probucol powder (A), sodium alginate powder (B), Probucol-sodium alginate microcapsule (C), and Probucol-sodium alginate mixed powder (D). Probucol manufactured by Sigma-Aldrich Co., St Louis, MO, USA.