Delivery of radix ophiopogonis polysaccharide via sucrose acetate isobutyrate-based in situ forming systems alone or combined with its mono-PEGylation

Figures & data

Table 1. SAIB-based in situ forming formulations and dosage regimen for FITC-labeled ROP (^FROP) or mono-PEGylated ROPs (^FMP-R) (n = 3).

Code	Formulation (w/w)	Drug	Dose (mg/kg)	Injection volume (ml/kg)
Ι	Aqueous solution 1	^FROP	15	2
II	Aqueous solution 2	^FROP	50	2
III	90%SAIB/10%Ethanol	^FROP	200	2
IV	90%SAIB/10%NMP	^FROP	200	2
V	90%SAIB/10%TA	^FROP	200	2
VI	90%SAIB/10%BB	^FROP	200	2
A	Aqueous solution 3	^FMP30k-R	75	2
B	Aqueous solution 4	^FMP30k-R	300	2
C	Aqueous solution 5	^FMP20k-R	75	2
D	Aqueous solution 6	^FMP40k-R	75	2
E	SAIB/PLGA10k/NMP 5:2:3	^FMP30k-R	300	2
F	SAIB/PLGA30k/NMP 4:2:4	^FMP30k-R	300	2
G	SAIB/PLGA40k/NMP 4:2:4	^FMP30k-R	300	2
H	SAIB/PLGA50k/NMP 3.5:2:4.5	^FMP30k-R	300	2
I	SAIB/PLGA10k/NMP 4.5:2.5:3	^FMP30k-R	300	2
J	SAIB/PLGA10k/NMP 4:3:3	^FMP30k-R	300	2
K	SAIB/PLA10k/NMP 4:3:3	^FMP30k-R	300	2
L	SAIB/PLA10k/Ethanol 4:3:3	^FMP30k-R	300	2
M	SAIB/PLGA40k/NMP 4.5:1.5:4	^FMP30k-R	300	2
N	SAIB/PLGA40k/NMP 5:1:4	^FMP30k-R	300	2
O	SAIB/PLGA50k/NMP 3.5:2:4.5	^FMP20k-R	300	2
P	SAIB/PLGA50k/NMP 3.5:2:4.5	^FMP40k-R	300	2

SAIB: sucrose acetate isobutyrate; ^FROP: fluoresceinisothiocyanate-labeled radix ophiopogonis polysaccharide; BB: benzyl benzoate; NMP: N-methyl-2-pyrrolidone; TA: triacetin; ^FMP_20k-R: FITC-labeled 20-kDa PEG mono-modified ROP; ^FMP_30k-R: FITC-labeled 30-kDa PEG mono-modified ROP; ^FMP_40k-R: FITC-labeled 40-kDa PEG mono-modified ROP; FITC: fluorescein isothiocyanate; PEG: polyethylene glycol; ROP: radix ophiopogonis polysaccharide; PLGA: poly(d,l-lactide-co-glycolide); PLA: polylactic acid.

Table 2. Pharmacokinetic parameters of ^FROP released from 90%SAIB/10% solvent. (n = 3).

		Parameters
Code	Formulation	AUC0–12 h (mg/l*h)	AUC0–t^a (mg/l*h)	Tmax (h)	Cmax (mg/l)	Cmax/Cs^b	Cmax/Cmin^c	MRT (h)	F^d (%)
Ι	Aqueous solution 1	–	37.74 ± 11.05	0.33 ± 0.00	14.44 ± 2.14	–	10.28 ± 2.77	2.32 ± 0.26
II	Aqueous solution 2	–	154.23 ± 8.153**	0.33 ± 0.00	59.74 ± 4.03**	–	37.06 ± 14.98	2.33 ± 0.29
III	90%SAIB/ethanol	384.59 ± 66.43	495.24 ± 78.67**##	1.00 ± 0.00**	128.74 ± 39.89**##	59.53 ± 20.66	105.20 ± 41.29**##	10.10 ± 1.74**##	80.28
IV	90%SAIB/NMP	351.80 ± 20.24	552.54 ± 35.66**##	1.33 ± 0.58	99.70 ± 18.57**	38.90 ± 17.23	71.48 ± 18.85**	12.19 ± 0.86**##	89.56
V	90%SAIB/TA	309.47 ± 7.67	537.05 ± 190.49**##	0.78 ± 0.19	96.09 ± 27.47**	29.33 ± 19.38	54.71 ± 8.53*	16.25 ± 6.24**##	87.05
VI	90%SAIB/BB	346.75 ± 50.11	488.53 ± 57.66**##	0.89 ± 0.19*	122.03 ± 12.84**##	41.60 ± 9.04	85.46 ± 9.08**##	12.41 ± 1.02**##	79.19

a For the aqueous solution, t =∞; for the other formulations, t is the last time point at which ^FROP was still detectable.

b The steady-state concentration (C_s) is the average value of the plasma level from 24 to 48 h for formulations III–VI.

c The minimal concentration (C_min) is the minimal value of the plasma level from T_max to the last time point at which ^FROP was still detectable.

d F = AUC_{0–t (ISFS)}/(4*AUC_{0–∞ (solution 2)}).

**p < .01 and *p < .05 compared with aqueous solution 1.

##p < .01 and #p < .05 compared with the aqueous solution 2.

Data are presented as mean ± standard deviation.

^FROP: fluorescein isothiocyanate-labeled radix ophiopogonis polysaccharide; NMP: N-methyl-2-pyrrolidone; BB: benzyl benzoate; BA: benzyl alcohol; TA: triacetin; PLGA: poly(d,l-lactide-co-glycolide); AUC: area under the concentration-time curve; MRT: mean residence time; C_max: maximum concentration in plasma; T_max: time taken to reach C_max.

Figure 1. Plasma ^FROP concentration-time profiles achieved by the SAIB/solvent systems. (□) aqueous solution 1, (☆) aqueous solution 2, (◆) SAIB/ethanol (9:1, w/w), (▲) SAIB/NMP (9:1, w/w), (▼) SAIB/TA (9:1, w/w), (•) SAIB/BB (9:1, w/w). The dose for all the SAIB/solvent systems was 200 mg/kg, while those for the control aqueous solutions 1 and 2 were 15 and 50 mg/kg, respectively. ^FROP: FITC-labeled radix ophiopogonis polysaccharide; FITC: fluorescein isothiocyanate; SAIB: sucrose acetate isobutyrate; BB: benzyl benzoate; NMP: N-methyl-2-pyrrolidone; TA: triacetin.

Figure 2. Plasma ^FMP_30k-R concentration-time profiles achieved by the SAIB/PLGA(PLA)/NMP systems (a, profiles achieved by the SAIB/PLGA/NMP systems with different molecular weights of PLGA; b, profiles achieved by the SAIB/PLGA_10k/NMP systems with different ratio; c, profiles achieved by the different SAIB/additive/solvent systems; and d, profiles achieved by the SAIB/PLGA_40k/NMP systems with different ratio.). (□) aqueous solution 3, (☆) aqueous solution 4, (◆) SAIB/PLGA_10k/NMP (5:2:3, w/w/w), (•) SAIB/PLGA_30k/NMP (4:2:4, w/w/w), (▲)SAIB/PLGA_40k/NMP (4:2:4, w/w/w), (▼) SAIB/PLGA_50k/NMP (3.5:2:4.5, w/w/w), (⬡) SAIB/PLGA_10k/NMP (4.5:2.5:3, w/w/w), (※) SAIB/PLGA_10k/NMP (4:3:3, w/w/w), (^) SAIB/PLA_10k/NMP (4:3:3, w/w/w), (△)SAIB/PLA_10k/Ethanol (4:3:3, w/w/w), (◃) SAIB/PLGA_40k/NMP (4.5:1.5:4, w/w/w), (▷)SAIB/PLGA_40k/NMP (5:1:4, w/w/w). The dose for all the SAIB-based systems and aqueous solution 4 was 300 mg/kg, while that for the control aqueous solution 3 was 75 mg/kg. ^FMP_30k-R: FITC-labeled 30 kDa PEG mono-modified ROP; SAIB: sucrose acetate isobutyrate; FITC: fluorescein isothiocyanate; PEG: polyethylene glycol; ROP: radix ophiopogonis polysaccharide; PLGA: poly(d,l-lactide-co-glycolide); PLA: polylactic acid; NMP: N-methyl-2- pyrrolidone; 10k, 10 kDa; 30k, 30 kDa; 40k, 40 kDa; and 50k, 50 kDa.

Table 3. Pharmacokinetic parameters of ^FMP-R released from SAIB/additives/solvent (n = 3).

			Parameters
Code	Formulation	Drug	AUC(0–5d) (mg/l*d)	AUC(0–t)^a (mg/l*d)	Tmax (d)	Cmax (mg/l)	Cmax/Cs^b	Cmax/Cmin^c	MRT (d)	F^d (%)
A	Aqueous solution 3	^FMP30k-R	130.31 ± 26.18	148.12 ± 31.25	2.00 ± 0.00	59.50 ± 27.70	–	9.01 ± 2.23	2.84 ± 0.11	–
B	Aqueous solution 4	^FMP30k-R	484.19 ± 20.70	580.32 ± 21.80	2.00 ± 0.00	239.60 ± 15.66	13.03 ± 1.49	40.03 ± 23.76	3.21 ± 0.14	–
C	Aqueous solution 5	^FMP20k-R	484.19 ± 20.70	35.31 ± 6.02	1.00 ± 0.00	19.61 ± 3.57	–	7.75 ± 0.39	2.20 ± 0.02	–
D	Aqueous solution 6	^FMP40k-R	484.19 ± 20.70	370.57 ± 59.28	3.00 ± 0.00	63.53 ± 7.25	–	6.88 ± 0.79	5.07 ± 0.04	–
E	SAIB/PLGA10k/NMP 5:2:3	^FMP30k-R	453.80 ± 125.01	688.03 ± 173.02	2.33 ± 0.58	192.72 ± 60.42	7.55 ± 1.78	12.18 ± 4.96	5.03 ± 0.35	116.13
F	SAIB/PLGA30k/NMP 4:2:4	^FMP30k-R	250.87 ± 20.25	608.49 ± 70.42	2.00 ± 0.00	120.67 ± 12.05**	6.93 ± 1.49	24.26 ± 4.21	9.77 ± 0.20**	102.70
G	SAIB/PLGA40k/NMP 4:2:4	^FMP30k-R	145.73 ± 52.50	599.30 ± 87.78	3.00 ± 0.00	52.56 ± 27.97**	3.27 ± 1.91*	7.58 ± 6.60	15.16 ± 3.09	101.15
H	SAIB/PLGA50k/NMP 3.5:2:4.5	^FMP30k-R	149.81 ± 44.09	653.53 ± 163.56	2.67 ± 0.58	57.96 ± 30.09**	5.11 ± 4.00*	8.36 ± 6.00	19.67 ± 1.48*	110.30
I	SAIB/PLGA10k/NMP 4.5:2.5:3	^FMP30k-R	345.39 ± 145.26	638.28 ± 279.22	2.00 ± 0.00	137.22 ± 30.66**	7.11 ± 1.72	9.79 ± 1.57	6.92 ± 0.18**	107.73
J	SAIB/PLGA10k/NMP 4:3:3	^FMP30k-R	226.27 ± 36.57	633.02 ± 93.63	2.67 ± 0.58	76.11 ± 8.88**	5.13 ± 0.49	10.39 ± 1.09	13.14 ± 0.73**	106.84
K	SAIB/PLA10k/NMP 4:3:3	^FMP30k-R	340.63 ± 37.91	592.42 ± 120.10	2.33 ± 0.58	120.83 ± 12.07**	10.93 ± 5.76	23.63 ± 9.28	8.00 ± 1.28	99.99
L	SAIB/PLA10k/Ethanol 4:3:3	^FMP30k-R	462.59 ± 21.75	730.58 ± 65.50	2.00 ± 0.00	202.94 ± 7.25	13.19 ± 2.40	25.53 ± 4.56	6.63 ± 0.47*	123.31
M	SAIB/PLGA40k/NMP 4.5:1.5:4	^FMP30k-R	219.80 ± 30.89	481.57 ± 99.77	2.00 ± 0.00	98.47 ± 30.55**	8.24 ± 3.49	30.09 ± 13.51	9.73 ± 0.79*	81.28
N	SAIB/PLGA40k/NMP 5:1:4	^FMP30k-R	349.85 ± 109.49	613.66 ± 194.27	2.00 ± 0.00	196.55 ± 69.16	9.57 ± 0.37	49.20 ± 0.88	6.16 ± 0.06**	103.57
O	SAIB/PLGA50k/NMP 3.5:2:4.5	^FMP20k-R	52.74 ± 25.31	140.63 ± 48.62	1.00 ± 0.00	20.41 ± 11.88	7.52 ± 1.98	12.56 ± 4.28	13.18 ± 1.65##	99.57
P	SAIB/PLGA50k/NMP 3.5:2:4.5	^FMP40k-R	504.17 ± 127.95	1599.36 ± 532.07	3.33 ± 0.58	191.86 ± 1.94&&	6.96 ± 1.70	25.07 ± 7.28	19.33 ± 2.23&&	107.90

a For the aqueous solution, t=∞; for the other formulations, t is the last time point at which ^FROP was still detectable.

b The steady-state concentration (C_s) is the average value of the plasma level from T_max to the last third point in the profile for B and Formulations E-P.

c The minimal concentration (C_min) is the minimal value of the plasma level from T_max to the last time point at which ^FROP was still detectable.

d For formulations E-N, F = AUC_{0–t (ISFS)}/(4*AUC_{0–∞ (solution 3)} ); for formulation O, F = AUC_{0–t (ISFS)}/(4*AUC_{0–∞ (solution 5)} ); for formulation P, F = AUC_{0–t (ISFS)}/(4*AUC_{0–∞ (solution 6)} ).

**p < .01 and *p < .05, compared with aqueous solution 2;

##p < .01 and #p < .05, compared with the aqueous solution 3.

&&p < .01 and &p < .05, compared with the aqueous solution 4. Data are presented as mean ± standard deviation.

SAIB: sucrose acetate isobutyrate; ^FMP_20k-R: FITC-labeled 20-kDa PEG mono-modified ROP; ^FMP_30k-R: FITC-labeled 30-kDa PEG mono-modified ROP; ^FMP_40k-R: FITC-labeled 40-kDa PEG mono-modified ROP; FITC: fluorescein isothiocyanate; PEG: polyethylene glycol; ROP: radix ophiopogonis polysaccharide; PLGA: poly(d,l-lactide-co-glycolide); PLA: polylactic acid; NMP: N-methyl-2-pyrrolidone; AUC: area under the concentration-time curve; MRT: mean residence time; C_max: maximum concentration in plasma; T_max: time taken to reach C_max.

Figure 3. Plasma ^FMP-R concentration-time profiles achieved by the SAIB/PLGA_50k/NMP systems loaded with different molecular weight ^FMP-R. (□) Aqueous solution 5 (^FMP_20k-R), (^) Aqueous solution 3 (^FMP_30k-R), (☆) aqueous solution 4 (^FMP_30k-R), (△) aqueous solution 6 (^FMP_40k-R), (▪) SAIB/PLGA_50k/NMP (3.5:2:4.5, w/w/w, ^FMP_20k-R), (•) SAIB/PLGA_50k/NMP (3.5:2:4.5, w/w/w,^FMP_30k-R), (▲) SAIB/PLGA_50k/ NMP (3.5:2:4.5, w/w/w, ^FMP_40k-R). The dose for all the SAIB-based systems and aqueous solution 4 was 300 mg/kg, while that for the control aqueous solutions 3, 5, and 6 was 75 mg/kg. ^FMP_20k-R: FITC-labeled 20 kDa PEG mono-modified ROP; ^FMP_30k-R: FITC-labeled 30 kDa PEG mono-modified ROP; ^FMP_40k-R: FITC-labeled 40 kDa PEG mono-modified ROP; FITC: fluorescein isothiocyanate; PEG: polyethylene glycol; ROP: radix ophiopogonis polysaccharide; SAIB: sucrose acetate isobutyrate; PLGA: poly(d,l-lactide-co- glycolide); NMP: N-methyl-2-pyrrolidone; 50k, 50 kDa.