Successful delivery of docetaxel to rat brain using experimentally developed nanoliposome: a treatment strategy for brain tumor

Figures & data

Table 1. Formulation composition, % yield, drug loading and loading efficiency of different formulations.

Formulation code	DTX:SPC:CHL (by weight)	Yields %*	% of drug loading*	Loading efficiency %*
NL1	1:5:5	42.03 ± 4.19	2.6 ± 0.45	28.61 ± 5.05
NL2	1:10:5	69.21 ± 4.75	5.48 ± 0.5	87.81 ± 7.82
NL3	1:15:5	49.89 ± 2.86	1.86 ± 0.5	70.26 ± 11.04

*Data show mean ± standard deviation of three different formulations or three different experiments in triplicate (where applicable).

Figure 1. FTIR spectral data of (A) DTX, (B) CHL and (C) SPC, (D) a mixture of CHL, SPC and (E) a mixture of drug with CHL, SPC, (F) the optimized formulation with DTX (L-DTX) and (G) formulation without DTX (B-DTX).

Figure 2. (A) Particle size distribution (B) Zeta potential value (C) Field emission scanning electron microscopic image at a magnifications of (70 000×) and (D) Cryo-TEM image of the experimental formulation (L-DTX).

Figure 3: (A) In vitro release profile of DTX from the experimental formulation (L-DTX), marketed formulation (Taxotere®) and free-DTX solution in phosphate buffer, pH 7.4. Data show mean ± standard deviation of three different experiments in triplicate. (B) Cell viability study by MTT assay of blank formulation (B-DTX), L-DTX (formulation with DTX), marketed preparation (Taxotere®) and free-drug (DTX) in C6 glioma cells of rats. Data show mean ± standard deviation of three different experiments. (C) Cellular localization study of FITC-L-DTX (F-DTX) at different time points by fluorescence microscopy in C6 glioma cells of rats and (D) Flow cytometric measurement of C6 glioma cells of rats incubated with F-DTX at 0.5 h and 6 h of treatments, indicating about 18%, and about 23% enhancement of uptake in terms of FITC incorporated liposomes in cells at 0.5 h (Figure 3D-II) and 6 h (Figure 3D-III) of treatments, respectively, in comparison to untreated cells (Figure 3D-I).

Table 2. Pharmacokinetic parameters and plasma to brain values in different groups of rats treated with DTX-loaded liposome (L-DTX), marketed formulation of DTX (Taxotere®) and free-drug (DTX), administered intravenously at a dose of 10 mg/kg of average body weight of the rats.

Formulation	*t1/2 (h)	**Cmax (ng/ml)	^#AUC0→t (ng.h/ml)	^##AUMC0→t (ng.h2/ml)	^$MRT (h)	^+CL (L/h)	^++Vss (L)	Mean plasma/brain value at different time interval in hour
L-DTX	1.97 ± 0.02^¶^,^€	1508.4 ± 33.9	2061.04 ± 88.19^¶	3630.19 ± 255.81^¶^,^€	1.76 ± 0.13^¶^,^€	4.85 ± 0.26^¶	8.55 ± 0.49^¶^,^€	0.5	0.016 ± 0.001
								1.0	0.058 ± 0.005^¶
								2.0	0.059 ± 0.008
								4.0	0.072 ± 0.017
Taxotere®	0.89 ± 0.05^€	1725.2 ± 179.1^¥	2192.57 ± 168.80^¥	2726.41 ± 431.27^€^,^¥	1.24 ± 0.08^€	4.56 ± 0.22^¥	5.67 ± 0.29^¥^,^€	0.5	0.019 ± 0.003
								1.0	0.063 ± 0.001^¥
								2.0	0.049 ± 0.005
								4.0	0.035 ± 0.0038
Free drug	0.81 ± 0.04^¶	1308.1 ± 54.7^¥	1499.25 ± 68.73^¶^,^¥	1587.77 ± 206.70^¶^,^¥	1.06 ± 0.08^¶	6.67 ± 0.30^¶^,^¥	7.06 ± 0.17^¶^,^¥	0.5	×××
								1.0	0.0143 ± 0.002^¶^,^¥
								2.0	×××
								4.0	×××

Values represent mean ± standard deviation (n = 3); Statistical calculations were performed using one-way ANOVA followed by the Tukey post hoc test using Origin Pro 8 (OriginLab, Northampton, MA). Differences were considered statistically significant when the probability value (p) is less than 0.05 at 95% confidence level.

* t_1/2, half-life.

** C_max, maximum blood concentration.

^# AUC_0→t, area under the concentration-time curve from time of injection (t = 0) to a determined time point.

^## AUMC, area under the first moment curve.

^$ MRT, mean residence time.

⁺ CL, clearance.

⁺⁺ V_ss, steady state volume of distribution.

^¶ Denotes comparison made between L-DTX and free drug.

^€ Denotes comparison made between L-DTX and Taxotere®.

^¥ Denotes comparison made between Taxotere® and free drug.

Figure 4: (A) Plasma level of DTX in rats after intravenous administration of L-DTX, free drug and Taxotere®. (B) Concentration of DTX in brain after intravenous administration of nanoliposomal formulation containing DTX (L-DTX), marketed formulation (Taxotere®) and free drug to rats at a dose of 10 mg/kg of DTX. Note: Data show mean ± standard deviation (n = 3).