Oral delivery of indinavir using mPEG-PCL nanoparticles: preparation, optimization, cellular uptake, transport and pharmacokinetic evaluation

Figures & data

Table 1. Considered variables and responses along with their levels and constraints.

Independent variables	Levels		Dependent variables	Units	Constraints
	−1	1	Particle size	nm	Min
Amount of polymer	10	100	Polydispersity index	–	Min
Surfactant conc. (mg/ml)	5	20	Loading efficiency	%	Max
Organic phase (ml)	1	15	Loading capacity	%	Max

Figure 1. ¹H NMR spectra of mPEG-PCL copolymer in CDCl3 (A). FT-IR spectrum of mPEG-PCL copolymer (B).

Table 2. Experimental design matrix, and analysis of variance for D-optimal design.

Independent variables (factors)				Dependent variables (responses)
Run	A	B	C	Particle size	Polydispersity index	Loading efficiency %	Loading capacity %
1	44.05	1.43	9.70	271.91	0.31	58.34	6.99
2	10.00	0.50	1.00	197.50	0.51	20.00	14.01
3	46.42	1.39	1.00	280.24	0.46	57.98	6.49
4	46.22	0.50	9.36	265.18	0.38	61.73	7.09
5	10.00	0.50	1.00	174.82	0.68	24.25	14.24
6	10.00	1.04	15.00	255.05	0.39	26.24	10.72
7	10.00	1.08	5.82	270.27	0.51	23.87	12.57
8	68.49	2.00	15.00	157.02	0.24	50.09	4.01
9	100.00	2.00	1.00	154.57	0.33	80.17	4.48
10	46.42	1.39	1.00	261.61	0.40	65.87	7.53
11	91.52	0.52	8.00	165.56	0.27	62.87	3.83
12	100.00	1.39	9.32	169.63	0.38	49.91	2.82
13	100.00	0.50	15.00	165.47	0.22	62.52	3.53
14	10.00	2.00	15.00	185.81	0.32	17.41	6.52
15	68.49	2.00	15.00	148.88	0.23	51.04	4.11
16	100.00	2.00	1.00	147.41	0.26	57.26	3.24
17	10.00	2.00	5.92	182.56	0.31	21.39	8.02
18	100.00	0.50	1.00	153.08	0.29	70.12	3.96
19	100.00	0.50	15.00	145.41	0.26	76.93	4.35
20	100.00	1.25	1.86	152.42	0.33	61.25	3.48

Summary of the statistical analysis of the responses
Dependent variables			Source of variations	Mean square	F value	Prob. > F
Particle size			Model	5026.76	16.18	<.0001	Sig.
			Lack of fit	483.29	3.50	.0975	Not Sig.
Polydispersity index			Model	0.07	21.60	<.0001	Sig.
			Lack of fit	3.342E-003	1.16	.4630	Not Sig.
Loading efficiency %			Model	806.26	16.10	<.0001	Sig.
			Lack of fit	18.74	0.23	.9336	Not Sig.
Loading capacity %			Model	39.97	48.38	<.0001	Sig.
			Lack of fit	1.13	3.39	.0974	Not Sig.

A: Polymer to drug ratio (mg); B: surfactant conc. (mg/ml); C: Organic phase (ml).

Figure 2. Interactive effect of surfactant concentration and amount of mPEG-PCL on the particle size and 3D surfaces (A,B); interactive effect of surfactant concentration and amount of mPEG-PCL on the entrapment efficiency and 3D surfaces (C,D).

Figure 3. AFM image of IDV-mPEG-PCL NPs (A). SEM image of IDV-mPEG-PCL NPs (B). DSC spectra of IDV, mPEG-PCL, the physical mixture of free IDV and MPEG-PCL and IDV-mPEG-PCL NPs (C). XRD spectra of IDV, mPEG-PCL, the physical mixture of free IDVand MPEG-PCL and IDV-mPEG-PCL NPS (D).

Figure 4. The release profiles of IDV-m-PEG-PCL NPS and free drug behavior through the dialysis membrane in PBS (pH 7.4, 37 °C) (A). Plasma concentration-time curves of IDV-mPEG-PCL NPs and IDV solution after oral administration (20 mg/kg of IDV in rat) (B). Effect of concentration on IDV transport from the apical to basolateral side of the Caco-2 cell monolayer. NPs concentrations and IDV (10, 100,and 200 μg/ml) (C). The Caco-2 cell uptake efficiency measurement after 3 h incubation with IDV-mPEG-PCL NPs and IDV at 37 °C. NPs concentrations and IDV (10, 100 and 200 μg/ml) (D). Data represent mean ± SD, n = 3.

Table 3. Summary of model parameters of IDV release data.

Models	Equation	Parameter	SGF (pH 1.2)	SIF (pH 6.8)	PBS (pH 7.4)
Zero-order	F = k0 × t	k0	0.59	1.055	0.23
		R^2	0.5252	0.3885	0.6002
		AIC	152	206	110.3019
First-order	F = 100 × [1 − Exp(−k1 × t)]	K1	0.009	0.107	0.003
		R^2	0.5854	0.8161	0.6146
		AIC	150.2551	191	109.5501
Higuchi	F = kH × t^0.5	kHC	0.003	9.780	2.151
		R^2	0.7171	0.6046	0.7696
		AIC	139	190.5671	95.8219
Hixson–Crowell	F = 100 × [1 − (1 – kHC × t) ^3]	kHC	0.003	0.014	0.001
		R^2	0.5642	0.6231	0.6097
		AIC	151	197	109
Korsmeyer–Peppas	F = kKP × t^n	kKP	21.339	37.985	7.109
		n	0.147	0.133	0.185
		R^2	0.9008	0.8418	0.9026
		AIC	109.5335	158.6175	72.7965

SGF: simulated gastric fluid; SIF: simulated intestinal fluid.

Table 4. The plasma pharmacokinetic parameters of IDV after oral administration of IDV solution, and IDV-mPEG-PCL NPs at a dose of 20 mg/kg in the rat.

Parameters	Units	IDV solution	IDV-mPEG-PCL NPs
AUC0–t	μg/mlh	131 ± 85.18	696.61 ± 295.44
Cmax	µg/ml	39.027 ± 11.24	53.84.83 ± 17.90
t1/2	h	2.23 ± 2.85	12.41 ± 4.14
MRT	h	5.068 ± 1.2	17.70 ± 4.39
CL/F	(mg)/(μg/ml)/h	0.038 ± 0.06	0.0071 ± 0.01
kel	1/h	0.311697238 ± 0.2	0.055 ± 0.16

Mean ± SD, (n = 7).