Preparation and characterization of Tamoxifen citrate loaded nanoparticles for breast cancer therapy

Figures & data

Table 1 Composition and drug loading of different nanoparticles

Formulation code	Amount of drug (mg)	Amount of polymer, PLGA (85:15) (mg)	Amount of FITC (μL)	Theoretical drug loading (%) (w/w)	Actual drug content in total formulation (mg/mg)*	Actual drug loading (%) (w/w)*
NP1	25	202	–	11	0.585±0.03	1.5078±0.02
NP2	40	202	–	16.5	0.874±0.02	2.678±0.5
NP3	60	202	–	22.9	1.136±0.5	4.088±0.2
NP4	200	202	–	50	3.715±0.6	27.16±2.08
FITC-NP4	200	202	100	50	3.503±0.8	27.01±1.75

Notes: Theoretical drug loading (%) = (amount of drug/amount of drug + amount of polymer) ×100.

* Mean ± SD, n=3.

Abbreviations: PLGA, polylactide-co-glycolide; FITC, fluorescein isothiocyanate; w/w, weight/weight.

Figure 1 Fourier transform infrared spectroscopy spectra.

Notes: (A) Tamoxifen citrate; (B) polylactide-co-glycolide (PLGA); (C) polyvinyl alcohol (PVA); (D) mixture of PLGA and PVA; (E) mixture of PLGA, PVA and Tamoxifen citrate; (F) blank nanoparticles (without drug); (G) nanoparticles loaded with Tamoxifen citrate.

Figure 2 Field emission scanning electron microscopic images.

Notes: Experimental formulations: (A) Formulation NP1 at 100,000×; (B) Formulation NP2 at 50,000×; (C) Formulation NP3 at 50,000×; (D) Formulation NP4 at 50,000×.

Abbreviations: IACS, Indian Association for the Cultivation of Science; LEI, low emission image; WD, working distance.

Table 2 Average particle size and zeta potential of the different formulations

Formulation code	Average particle size (nm)	Polydispersity index	Zeta potential (mV)
NP1	242.5	1.00	−10.5
NP2	331.8	0.143	−11.6
NP3	375.6	0.016	−16.5
NP4	382.0	0.611	−16.1

Figure 3 Average particle size of different formulations.

Notes: (A) Formulation NP1: 242.5 nm; (B) Formulation NP2: 331.8 nm; (C) Formulation NP3: 375.6 nm; (D) Formulation NP4: 382.0 nm.

Figure 4 Zetapotential of different formulations.

Notes: (A) Formulation NP1: −10.5 mV; (B) Formulation NP2: −11.6 mV; (C) Formulation NP3: −16.5 mV; (D) Formulation NP4: −16.1 mV.

Figure 5 Transmission electron scanning microscopic images of experimental formulation NP4.

Notes: (A) At lower magnification (shown by bar) and (B) at higher magnification (shown by bar).

Table 3 Weight % and atomic % of elements in various nanoparticles

	CK		OK		NK
	BNPS	TNPS	BNPS	TNPS	BNPS	TNPS
Weight %	26.23%	41.09%	48.84%	26.00%	24.92%	32.90%
Atomic %	31.13%	46.26%	43.51%	21.98%	25.36%	31.76%

Abbreviations: BNPS, blank nanoparticles; CK, carbon counts; OK, oxygen counts; NK, nitrogen counts; TNPS, Tamoxifen citrate loaded nanoparticles.

Figure 6 Energy dispersive X-ray (EDX).

Notes: (A) Blank nanoparticles (BNPS); and (B) Tamoxifen citrate loaded nanoparticles (TNPs).

Abbreviation: cts, counts.

Table 4 R² values of different drug release kinetics models and release exponents of different formulations

Formulation code	Correlation coefficient (R^2)
	Zero order	First order	Korsmeyer–Peppas	Hixson–Crowell	Higuchi	Release exponent (n)
NP1	0.8723	0.2745	0.9976	0.5140	2.358	1.09
NP2	0.6703	0.0727	0.9652	0.3327	0.0323	0.914
NP3	0.7555	0.0802	0.9721	0.4064	0.1825	0.901
NP4	0.7501	0.0830	0.9736	0.4082	0.3626	0.852

Figure 7 Release of Tamoxifen citrate from different formulations: NP1, NP2, NP3, and NP4.

Figure 8 Confocal microscopy and differential interference contrast (DIC) images of MCF-7 cells.

Notes: (A) Formulation NP4 at concentration 50 μL for 3 hours; (B) Formulation NP4 at concentration 100 μL for 3 hours.

Figure 9 Comparison of in vitro MCF-7 cell viability (%) upon the treatment of Tamoxifen citrate loaded nanoparticles, nanoparticles without a drug and with the free drug.

Abbreviation: MCF-7, Michigan Cancer Foundation-7.