Preparation and performance evaluation of saquinavir laden cationic submicron emulsions

Figures & data

Table 1.  Compositions (%) (w/w) of different optimized submicron emulsion incorporating SQ.

Ingredients	Emulsion (E)	Stearylamine emulsion (SE)*	Protamine emulsion (PE)**	Chitosan emulsion (CE)***
Stearylamine	—	0.5	—	—
Protamine	—	—	0.1	—
Chitosan	—	—	—	0.5
MCT oil	10	10	10	10
Lecithin	0.75	0.75	0.75	0.75
Pluronic F-68	1.25	1.25	1.25	1.25
Water qs	100	100	100	100

* In SE formulation 0.5% w/w of stearylamine was incorporated in emulsion (E).

** In PE formulation 0.1 %w/w protamine was incorporated in emulsion (E).

*** In CE formulation 0.5% w/w of chitosan was incorporated in emulsion (E).

MCT oil: Medium chain triglycerides.

Table 2.  Zeta potentials; mean particle size and entrapment efficiency of submicron emulsion formulations.

Formulation	Zeta potential (mV)	Mean globule size (nm)	Drug (SQ) entrapment (%)	pH of emulsion
CE	+15.83	304 ± 11.0	99 ± 2.3	5.8
PE	+12.84	278 ± 17.6	96 ± 1.8	7.2
SE	+12.40	256 ± 21.3	97 ± 1.4	7.5
E	−11.00	251 ± 14.0	98 ± 1.5	7.4

Data represented as ± SD of three set of experiments (n = 3).

CE: Submicron emulsion containing chitosan as charge inducer. PE: Submicron emulsion containing protamine as charge inducer. SE: Submicron emulsion containing stearylamine as charge inducer. E: Plain emulsion without any charge inducer.

Figure 1.  Normal phase contrast microscopy of various submicron emulsions (magnification ×100). E: Plain emulsion without and charge inducer. SE: Submicron emulsion containing stearylamine as charge inducer. PE: Submicron emulsion containing protamine as charge inducer. CE: Submiron emulsion containing chitosan as charge inducer.

Figure 2.  Cumulative release profile of SQ from submicron emulsion in PBS, pH 7.4. The values represented are means of three individual experiments. The experiment was performed using dialysis tubing (with cut-off mol. wt. 12,000). CE: Submicron emulsion containing chitosan as charge inducer. PE: Submicron emulsion containing protamine as charge inducer. SE: Submicron emulsion containing stearylamine as charge inducer. E: Plain emulsion without any charge inducer.

Table 3.  Effect of storage time on stability of different submicron emulsion formulations at room temperature.

Formulation	Mean particle size (nm)		Drug content (mg)		Zeta potential
	Initial	90 days	Initial	90 days	Initial	90 days
E	291 ± 14.0	298 ± 11.0	4.90	4.87	−11.0	−13.0
CE	304 ± 11.0	313 ± 9.8	4.95	4.91	+15.83	+14.98
SE	256 ± 21.3	266 ± 13.2	4.85	4.80	+12.40	+11.81
PE	278 ± 17.6	290 ± 16.0	4.80	4.67	+12.84	+12.648

Data represented as ± SD of three set of experiments (n = 3).

CE: Submicron emulsion containing chitosan as charge inducer. PE: Submicron emulsion containing protamine as charge inducer. SE: Submicron emulsion containing stearylamine as charge inducer. E: Plain emulsion without any charge inducer.

Figure 3.  Effect of different submicron emulsion on cell viability on J 774 MΦ at three different concentrations (A = 1 μg/ml; B = 10 μg/ml; C = 100 μg/ml) by MTT assay. The error bars indicates ± SD of three set of experiments (n = 3). CE: Submicron emulsion containing chitosan as charge inducer. PE: Submicron emulsion containing protamine as charge inducer. SE: Submicron emulsion containing stearylamine as charge inducer. E: Plain emulsion without any charge inducer.

Figure 4.  Apparent permeability coefficient (×10⁻⁶) of various submicron emulsions obtained using in-vitro everted intestinal sac method. The error bars indicates ± SD of three sets of experiments (n = 3). CE: Submicron emulsion containing chitosan as charge inducer. PE: Submicron emulsion containing protamine as charge inducer. SE: Submicron emulsion containing stearylamine as charge inducer. E: Plain emulsion without any charge inducer.

Figure 5.  Effect of different formulations on lactate dehydrogenase (LDH) in ileal loop of rat small intestine. The error bars indicates ± SD of three set of experiments (n = 3). CE: Submicron emulsion containing chitosan as charge inducer. PE: Submicron emulsion containing protamine as charge inducer. SE: Submicron emulsion containing stearylamine as charge inducer. E: Plain emulsion without any charge inducer. Triton x-100 and plain saline was taken as positive and negative control, respectively.