Dual cross-linked pulsatile beads for chronotherapy of asthma: Development and evaluation

Figures & data

Table 1.  Composition and conditions for formulation of dual cross-linked beads.

Ingredients	Formulation code
	B1	B2	B3	B4	B5	B6	B7	B8
Dispersed phase
TPH	100	100	100	100	100	100	100	100
Sodium Alginate*	450	500	450	450	450	450	450	450
DRG*	50	100	50	50	50	50	50	50
Distilled water**	10	10	10	10	10	10	10	10
Dispersion medium
CaCl2 (Monohydrate)***	5%	5%	10%	—	—	10%	10%	10%
AlCl3***	—	—	—	5%	10%	10%	10%	10%
Cross-linking time (min)	15	15	15	15	15	15	20	25

* quantity in mg; ** quantity in ml; *** quantity in % w/v.

Table 2.  The operating parameters used for coating of TPH beads.

Sr. no.	Process parameters	Values
1	Inlet temperature (°C)	45–50
2	Outlet temperature (°C)	35–38
3	Nozzle diameter (mm)	1.0
4	Atomization pressure (mPa)	45– 50
5	Spray rate (ml/min)	1.5

Table 3.  Physical characterization of formulated dual cross–linked beads.

Batchcode	Avg.diameter(mm) ± SD	Production yield(%) ± SD	Entrapment efficiency ± SD(mg/100 mg beads)	% Swelling± SD	Circularity± SD	Roundness± SD
B1	1.63 ± 0.16	68.42 ± 0.34	9.27 ± 0.16	11.05 ± 0.47	0.7729 ± 0.0514	1.2204 ± 0.0778
B2	1.68 ± 0.15	75.76 ± 0.23	13.68 ± 0.35	13.42 ± 0.24	0.7708 ± 0.0270	1.2207 ± 0.0433
B3	1.43 ± 0.16	71.99 ± 0.43	12.77 ± 0.26	9.90 ± 0.61	0.7996 ± 0.0317	1.1771 ± 0.0462
B4	1.97 ± 0.19	75.53 ± 0.23	15.99 ± 0.17	11.97 ± 0.30	0.8048 ± 0.0324	1.1694 ± 0.0453
B5	1.24 ± 0.05	85.70 ± 0.14	15.67 ± 0.16	8.33 ± 0.23	0.7957 ± 0.0324	1.1830 ± 0.0498
B6	1.54 ± 0.08	92.68 ± 0.37	16.44 ± 0.27	9.14 ± 0.51	0.7977 ± 0.0163	1.1787 ± 0.0246
B7	1.41 ± 0.06	88.84 ± 0.26	19.82 ± 0.38	7.67 ± 0.27	0.7491 ± 0.0341	1.2569 ± 0.0576
B8	1.50 ± 0.19	86.34 ± 0.31	16.84 ± 0.17	5.16 ± 0.73	0.7867 ± 0.0451	1.1981 ± 0.0695

Figure 1.  SEM images of dual cross-linked beads at different magnifications.

Figure 2.  Drug release profiles of uncoated beads.

Figure 3.  Drug release profiles of coated beads.

Figure 4.  In vivo radio imaging study in rabbits at an interval of 1 h (a), 2 h (b), 4 h (c), 5 h (d), 6 h (e), and 7 h (f).