Table 1.

Physicochemical characteristics and batch to batch variability of PLGA nanoparticles prepared using the optimized procedure (represented as mean ± sd, n=5 batches prepared on different days).

Nanoparticles	PLGA (Amount and Concentration in EA)	Surfactant (Amount and Concentration in DW)	Mean Particle Size (z-Average) (nm) ± S.D.	Mean PDI ± S.D.	Mean Zeta Potential (mV) ± S.D.
Anionic Scheme I	50 mg (6.66 mg/mL)	100 mg (PF68) (10 mg/mL)	164.1 ± 8.5	0.09 ± 0.00	-28.1 ± 1.8
Anionic Scheme II	100 mg (10 mg/mL)	200 mg (PF68) (10 mg/mL)	140.0 ± 7.5	0.11 ± 0.04	-31.0 ± 3.0
Uncharged Scheme III	30 mg (3.33 mg/mL)	250 mg (PVA) (25 mg/mL)	169.7 ± 7.5	0.10 ± 0.02	-1.3 ± 0.8
Cationic Scheme IV	30 mg (3.33 mg/mL)	10 mg (CS) (1 mg/mL)	184.2 ± 7.6	0.17 ± 0.03	+30.2 ± 6.0
Anionic Scheme V	175 mg (29 mg/mL)	1000 mg (PF68) (100 mg/mL)	393.3 ± 28.9	0.22 ± 0.06	-18.0 ± 2.0
Anionic Scheme VI	100 mg (10 mg/mL)	200 mg (PF68) (10 mg/mL)	58.3 ± 1.9	0.13 ± 0.03	-26.5 ± 2.3

PF68 - Poloxamer 188, PVA - Polyvinyl alcohol, CS- Chitosan, EA- Ethylacetate, DW- Distilled water. Dynamic light scattering measurements were performed using a Malvern Zetasizer Nano Series running DTS software and operating a 4 mW He-Ne laser at 633 nm. Analysis was performed at an angle of 173° and a constant temperature of 25°C. The z-average particle size (d.nm) and polydispersity index (PDI) are reported. The PDI was used to describe the width of the particle size distribution. It was calculated from a Cumulants analysis of the DLS measured intensity autocorrelation function and is related to the standard deviation of the hypothetical Gaussian distribution (i.e., PSD = σ2/ZD2, where σ is the standard deviation and ZD is the Z average mean size).