Oleic acid derivative of polyethylenimine-functionalized proliposomes for enhancing oral bioavailability of extract of Ginkgo biloba

Figures & data

Table 1. Composition of GbE proliposomes.

Formulation	Molar ratio (EPC:cholesterol)	bPEI-OA (mg)
I	3:1	0
II	2:1	0
III	1:1	0
IV	1:2	0
V	2:1	20.63
VI	2:1	41.25
VII	2:1	82.50

Each formulation contains 250 μM EPC, 200 mg GbE, and 1500 mg mannitol.

Table 2. The information for MRM parameters used for the flavonoid glycosides and terpene lactones.

Compound	Precursor ion	Cone voltage (V)	Production	Collision energy (eV)
Quercetin	303	20	153	32
Kaempferol	287	20	153	30
Isorhmnetin	317	20	153	30
Bilobalide	327	40	111	16
Ginkgolide A	409	50	345	18
Ginkgolide B	425	42	305	24
Ginkgolide C	441	48	325	22
Taxifolin (IS)	305	20	153	16

Table 3. Characterization of GbE proliposome formulations.

Formulation	Particle size (nm)	PDI	Zeta potential (mV)	EEf	EEt
I	178 ± 28	0.287	−4.6 ± 2.4	71.2 ± 2.3	77.2 ± 1.9
II	204 ± 19	0.195	−5.7 ± 3.1	83.3 ± 2.2	87.6 ± 2.5
III	229 ± 22	0.203	−5.3 ± 2.8	78.6 ± 1.7	83.3 ± 1.8
IV	186 ± 16	0.254	−3.8 ± 2.1	74.5 ± 1.8	80.5 ± 2.3
V	187 ± 21	0.186	+12.3 ± 2.7	85.4 ± 2.6	89.7 ± 2.9
VI	127 ± 15	0.145	+25.2 ± 3.2	93.1 ± 3.2	96.5 ± 2.6
VII	105 ± 21	0.138	+37.6 ± 4.5	87.4 ± 4.1	93.2 ± 3.1

Figure 1. Scanning electron micrographs of proliposome powders (A) formulation II and (B) formulation VI both at ×20 000 maginfication.

Figure 2. In vitro release profiles of (A) flavonoid glycosides and (B) terpene lactones from proliposome formulations in hydrochloric acid (pH 1.2) and phosphate buffer saline (pH 6.8) (mean ± SD, n = 3).

Figure 3. DSC thermograms of (A) GbE, (B) cholesterol, (C) mannitol, (D) physical mixture, (E) proliposome powders (formulation VI).

Figure 4. FT-IR spectra of (A) GbE, (B) cholesterol, (C) mannitol, (D) physical mixture, (E) proliposome powders (formulation VI).

Table 4. In situ intestinal absorption parameters of seven components from control, formulation II and VI, respectively (mean ± SD, n = 3).

Compound	Ka × 10^−4 (s^−1)	Papp × 10^−5 (cm·s^−1)	ER
Quercetin
Control	0.87 ± 0.22	0.70 ± 0.18	1.00
Formulation II	2.42 ± 0.52^a,1	1.99 ± 0.44^a,1	2.84
Formulation VI	3.96 ± 0.55^c,1 a,2	3.30 ± 0.48^c,1 a,2	4.71
Kaempferol
Control	1.41 ± 0.22	1.17 ± 0.19	1.00
Formulation II	2.29 ± 0.36^a,1	1.88 ± 0.30^a,1	1.61
Formulation VI	3.16 ± 0.25^c,1 a,2	2.62 ± 0.21^c,1 a,2	2.24
Isorhmnetin
Control	1.21 ± 0.16	0.97 ± 0.13	1.00
Formulation II	2.33 ± 0.56^a,1	1.91 ± 0.47^a,1	1.97
Formulation VI	3.74 ± 0.34^c,1 a,2	3.12 ± 0.30^c,1 a,2	3.22
Bilobalide
Control	6.66 ± 0.57	5.77 ± 0.51	1.00
Formulation II	7.35 ± 0.39	6.40 ± 0.36	1.11
Formulation VI	7.95 ± 0.45^a,1	7.01 ± 0.41^a,1	1.21
Ginkgolide A
Control	3.44 ± 0.67	2.87 ± 0.58	1.00
Formulation II	6.84 ± 0.93^b,1	5.90 ± 0.92^b,1	2.06
Formulation VI	9.07 ± 0.82^c,1 a,2	8.09 ± 0.80^c,1 a,2	2.82
Ginkgolide B
Control	3.68 ± 0.53	3.08 ± 0.46	1.00
Formulation II	7.43 ± 1.18^b,1	6.51 ± 1.18^b,1	2.11
Formulation VI	10.21 ± 1.20^c,1 a,2	9.21 ± 1.18^c,1 a,2	2.99
Ginkgolide C
Control	2.99 ± 0.40	2.48 ± 0.35	1.00
Formulation II	8.44 ± 1.30^b,1	7.44 ± 1.27^b,1	3.00
Formulation VI	11.09 ± 0.78^c,1 a,2	10.20 ± 0.76^c,1 a,2	4.11

Superscript 1, 2 indicate control and formulation II, respectively.

Superscript a, b, c indicate significant difference at p < 0.05, p < 0.01, and p < 0.001, respectively.

Figure 5. Concentration-time profiles of seven components in rat plasma following oral administration of control, formulation II and VI, respectively (mean ± SD, n = 6).

Table 5. Pharmacokinetic parameters of seven components in rats following oral administration of control, formulation II and VI, respectively (mean ± SD, n = 6).

Compound	Cmax (ng/ml)	AUC0–t (ng/ml/h)	Tmax (h)	T1/2 (h)	K (×10^−1, h^−1)	RA
Quercetin
Control	5.88 ± 1.91	41.81 ± 16.59	0.14 ± 0.04	6.76 ± 0.87	1.04 ± 0.13	1.00
Formulation II	20.95 ± 4.26^c,1	124.91 ± 9.12^c,1	0.33 ± 0.00^c,1	8.99 ± 0.62^c,1	0.77 ± 0.05^c,1	2.99
Formulation VI	42.76 ± 3.27^c,1,2	202.86 ± 58.09^c,1 b,2	0.33 ± 0.00^c,1	9.97 ± 1.15^c,1	0.70 ± 0.08^c,1	4.85
Kaempferol
Control	35.37 ± 6.90	441.19 ± 46.38	6.00 ± 1.26	10.60 ± 1.11	0.66 ± 0.07	1.00
Formulation II	49.39 ± 4.74^b,1	818.85 ± 66.21^c,1	7.00 ± 1.10	13.44 ± 0.76^c,1	0.52 ± 0.03^b,1	1.86
Formulation VI	59.81 ± 4.48^c,1 b,2	973.77 ± 98.03^c,1 b,2	7.33 ± 1.03	14.44 ± 1.28^c,1	0.48 ± 0.04^c,1	2.21
Isorhmnetin
Control	16.28 ± 1.88	207.44 ± 14.32	5.00 ± 1.10	10.18 ± 0.93	0.69 ± 0.06	1.00
Formulation II	25.54 ± 3.37^c,1	415.07 ± 40.24^c,1	7.33 ± 1.03^b,1	12.45 ± 0.94^b,1	0.56 ± 0.04^b,1	2.00
Formulation VI	39.03 ± 6.92^c,1 b,2	680.37 ± 145.67^c,1 b,2	8.67 ± 1.03^c,1	12.48 ± 1.92^a,1	0.57 ± 0.08^a,1	3.28
Bilobalide
Control	90.18 ± 14.07	331.82 ± 53.66	1.33 ± 0.52	1.82 ± 0.37	3.93 ± 0.71	1.00
Formulation II	92.69 ± 11.77	371.80 ± 23.61	2.00 ± 0.00	1.76 ± 0.06	3.95 ± 0.13	1.12
Formulation VI	94.05 ± 17.36	415.00 ± 76.20	1.67 ± 0.52	1.66 ± 0.52	3.43 ± 0.50	1.25
Ginkgolide A
Control	96.24 ± 8.31	257.05 ± 18.60	0.75 ± 0.27	1.87 ± 0.75	4.08 ± 1.17	1.00
Formulation II	165.09 ± 13.07^c,1	609.55 ± 38.56^c,1	1.00 ± 0.00	6.20 ± 1.64^c,1	1.19 ± 0.32^c,1	2.37
Formulation VI	242.92 ± 23.34^c,1,2	812.87 ± 109.62^c,1 b,2	1.00 ± 0.00	6.54 ± 1.24^c,1	1.09 ± 0.21^c,1	3.16
Ginkgolide B
Control	37.73 ± 6.66	122.15 ± 5.32	1.00 ± 0.00	2.21 ± 0.47	3.25 ± 0.64	1.00
Formulation II	75.83 ± 5.05^c,1	349.05 ± 50.55^c,1	2.00 ± 0.00	6.27 ± 1.14^c,1	1.14 ± 0.20^c,1	2.86
Formulation VI	112.16 ± 20.79^c,1,2	591.10 ± 99.31^c,1,2	2.00 ± 0.00	9.55 ± 1.26^c,1,2	0.74 ± 0.09^c,1 b,2	4.84
Ginkgolide C
Control	5.80 ± 0.25	30.86 ± 5.85	1.50 ± 0.55	3.71 ± 0.47	1.89 ± 0.25	1.00
Formulation II	13.16 ± 2.81^c,1	102.92 ± 16.43^c,1	3.33 ± 1.03^b,1	6.60 ± 1.06^c,1	1.07 ± 0.16^c,1	3.34
Formulation VI	19.62 ± 4.77^c,1 a,2	145.71 ± 25.45^c,1 b,2	4.00 ± 0.00^c,1	7.69 ± 0.91^c,1	0.91 ± 0.11^c,1	4.72

Superscript 1, 2 indicate control and formulation II, respectively.

Superscript a, b, c indicate significant difference at p < 0.05, p < 0.01, and p < 0.001, respectively.