Transdermal delivery of oxybutynin chloride proniosomal gels for the treatment of overactive bladder

Figures & data

Table 1. Composition of oxybutynin chloride proniosomal gels.

Gel code	Surfactant type	Ratio (mg)	Cholesterol (mg)	Glyceryl distearate (mg)	Soy lecithin (mg)	Wecobee (mg)	Comments
P1	S20:S40	500:500	–	100	100	100	Yellowish semi-solid
P2	S20:S60	500:500	–	100	100	100	Yellowish semi-solid
P3	S20:S60	500:500	100	–	100	100	Yellowish gel
P4	T20:T80	500:500	100	–	100	100	Yellowish gel
P5	T20:T80	900:100	100	–	100	100	Yellowish gel
P6	T20:T80	100:900	100	–	100	100	Whitish gel
P7	T20:T80	500:500	–	100	100	100	Whitish gel
P8	T20:T80	900:100	–	100	100	100	Whitish gel
P9	T20:T80	100:900	–	100	100	100	Whitish gel

S, Span; T, Tween. Each formulation contained 1% of drug, 0.5 mL of isopropyl alcohol and 0.5 mL of 10% glycerol solution.

Table 2. Entrapment efficiency and vesicle size of hydrated proniosomes.

Gel code	Entrapment efficiency (%) ± SD	Vesicle size (nm) ± SD
P1	91.65 ± 1.59	385.3 ± 1.6
P2	89.45 ± 1.23	506.0 ± 21
P3	96.41 ± 2.47	380.4 ± 5.3
P4	93.65 ± 1.28	5010.0 ± 2.17
P5	88.23 ± 0.79	3880.0 ± 111.8
P6	91.56 ± 4.31	3133.0 ± 151
P7	91.34 ± 1.89	1092.0 ± 56.5
P8	87.05 ± 3.56	869.2 ± 17.6
P9	91.28 ± 2.78	1534.0 ± 73.0

Table 3. Change in entrapment efficiency after storage for 3 months.

		Drug content (%)
Gel code	Period	5 ± 2 °C	25 ± 0.5 °C	45 ± 0.5 °C
P3	Initial	96.41 ± 2.47	96.41 ± 2.47	96.41 ± 2.47
	After 3 months	94.98 ± 1.56	93.12 ± 2.35	90.63 ± 1.57
P4	Initial	93.65 ± 1.28	93.65 ± 1.28	93.65 ± 1.28
	After 3 months	91.79 ± 2.08	90.19 ± 1.14	87.68 ± 1.32

Figure 1. Optical microscope images. (A, B) P3 gel with lower and higher levels of hydration, respectively; (C, D) P4 gel with lower and higher levels of hydration, respectively.

Figure 2. Hydrated P3 proniosomal formulations A, B and C (with magnifications of 500×, 1000× and 2000×, respectively): hydrated P4 proniosomal formulations D, E and F (with magnifications of 500×, 1000× and 2000×, respectively).

Figure 3. ATR-FTIR spectra of P3 proniosomal gel and its individual components.

Figure 4. ATR-FTIR spectra of P4 proniosomal gel and its individual components.

Figure 5. Percent cumulative permeation of various proniosomal formulations through mouse skin in vitro. Each plot represents the mean ± SD of 4 rats with p < 0.05.

Table 4. Percent cumulative permeation and permeation rate of oxybutynin chloride proniosomes across mouse skin in vitro.

Gel code	Percent cumulative permeation (%) ± SD	Permeation rate (μg/cm^2/h) ± SD
P1	72.70 ± 0.65	116.41 ± 0.86
P2	77.03 ± 0.23	125.06 ± 0.22
P3	82.93 ± 0.41	156.77 ± 0.55
P4	62.95 ± 0.24	88.04 ± 0.17
P5	53.14 ± 0.67	83.15 ± 0.94
P6	64.41 ± 0.03	66.99 ± 0.53
P7	57.65 ± 0.98	99.43 ± 0.87
P8	43.94 ± 0.36	67.98 ± 0.24
P9	51.96 ± 0.58	74.83 ± 0.43

Figure 6. (A) Effect of control, oral and transdermal administration of oxybutynin chloride proniosomal gel (P3 and P4) on pilocarpine-induced salivary secretion in rats. (B) Recovery of pilocarpine-induced salivary secretion after transdermal administration of oxybutynin chloride in rats. Each column represents the mean ± SD of four rats. Statistically significant data (p < 0.05 = ***).

Figure 7. Histologic images of bladders in different groups of rats. (A) control; (B and C) acetic acid-induced overactive bladder; (D) oxybutynin treated (p.o.); (E) P3 gel-treated; (F) P4 gel-treated.