Bioavailability enhancement of ondansetron after nasal administration of Caesalpinia pulcherrima-based microspheres

Figures & data

Table 1. Formula for different batches of ondansetron hydrochloride-loaded CPG microspheres.

Formulation code	Drug (mg)	Polymer (mg)	Inlet temperature (°C)	Aspirator rate (Nm^3/h)	Feed rate (ml/min)
B1	600	1200	150	45	2
B2	600	2400	150	45	2
B3	600	1200	160	45	2
B4	600	2400	160	45	2
B5	600	1200	150	55	2
B6	600	2400	150	55	2
B7	600	1200	160	55	2
B8	600	2400	160	55	2

Table 2. Characteristics of prepared ondansetron hydrochloride-loaded microspheres.

Formulation code	% Yield	Drug content (mg of drug/g of microspheres)	Entrapment efficiency (% ± SD)*	Mean particle size (µm ± SD)*	In-vitro mucoadhesion (% ± SD)*	Degree of swelling (α) (% ± SD)*
B1	20.74	235	80.70 ± 0.98	8.84 ± 0.97	72.41 ± 1.43	0.85 ± 0.26
B2	32.87	170	84.15 ± 1.03	9.44 ± 1.01	80.58 ± 5.80	0.88 ± 0.59
B3	22.69	256	82.51 ± 0.75	9.04 ± 1.3	75.90 ± 6.04	0.84 ± 0.47
B4	29.31	202	85.32 ± 0.46	9.66 ± 1.07	82.62 ± 1.59	0.89 ± 0.43
B5	24.84	354	86.56 ± 1.33	8.3 ± 1.81	77.00 ± 7.60	0.86 ± 0.60
B6	41.93	340	88.59 ± 0.67	11.11 ± 0.48	83.15 ± 9.60	0.91 ± 0.51
B7	22.20	280	87.22 ± 0.87	9.92 ± 1.57	78.15 ± 4.38	0.87 ± 0.50
B8	35.64	300	89.41 ± 0.83	11.34 ± 1.06	84.45 ± 3.31	0.92 ± 0.76

*n = 3.

Figure 1. Scanning electron micrograph of ondansetron hydrochloride-loaded microspheres.

Figure 2. Particle size analysis of ondansetron hydrochloride-loaded microspheres.

Figure 3. Zeta potential distribution curve of ondansetron-loaded CPG microspheres.

Figure 4. DSC spectra of ondansetron hydrochloride (OND), CPG and ondansetron hydrochloride-loaded microspheres (OCP).

Figure 5. X-ray diffractogram of ondansetron hydrochloride (OND), CPG and ondansetron hydrochloride-loaded microspheres (OCP).

Figure 6. In-vitro drug release of ondansetron hydrochloride from microspheres.

Table 3. In-vitro release kinetic parameter of ondansetron hydrochloride-loaded CPG from microspheres.

	R ^2
Formulation code	Zero order	Higuchi	Korsemeyer Peppas
B1	0.9135	0.9931	0.5265
B2	0.9791	0.9296	0.6813
B3	0.9188	0.9869	0.5229
B4	0.9284	0.9214	0.6124
B5	0.9206	0.9005	0.5523
B6	0.9210	0.8083	0.7101
B7	0.9542	0.9450	0.5596
B8	0.9303	0.7822	0.7980

Figure 7. Light photomicrograph of nasal mucosa, untreated mucosa (A) and microspheres treated mucosa (B).

Figure 8. Comparative profile of nasal and oral drug concentrations in plasma versus time.

Table 4. Comparative pharmacokinetic parameters of ondansetron hydrochloride following administration of oral solution and nasal microspheres in rabbits.

Parameter	Oral solution	Nasal microsphere
C max (ng/ml)	29 ± 19.32	34 ± 20.23
T max (min)	15	60
AUC0–300 (ng/ml min)	22.46 ± 3.46	40.08 ± 2.48
AUC0–∞ (ng/ml min)	23.98 ± 4.32	43.04 ± 1.67
F rel (%)	34.24 ± 2.89	58.65 ± 4.54