Development of Controlled Release Sildenafil Formulations for Vaginal Administration

Figures & data

TABLE 1 Contents of vaginal tablet formulations

	F-1	F-2	F-3	F-4	F-5	F-6	F-7	F-8	F-9
Sildenafil	100 mg	100 mg	100 mg	100 mg	100 mg	100 mg	100 g	100 mg	100 g
Lactose	150 mg	100 mg	75 mg	50 mg		100 mg	75 mg	50 mg
PC						50 mg	75 mg	100 mg	150 mg
CH		50 mg	75 mg	100 mg	150 mg

TABLE 2 Contents of sodium alginate formulations

Formulations	Sodium Alginate %	Sildenafil %
FF1	0.5	0.5
FF2	1	1
FF3	0.5	1
FF4	1	0.5
S1	2	1
S2	3	0.5
S3	2	0.5
S4	3	1

FIG. 1 The release characteristics of vaginal sildenafil tablets containing chitosan.

FIG. 2 The release characteristics of PC containing tablets.

TABLE 3 Release kinetics of sildenafil tablets

Kinetics
Formulation	Zero-order	First-order	Hixson-Crowell	Q√t
F1
r^2	0.969	0.961	0.981	0,887
Slope	0,586	−0,018	0,019	5,173
Residuals	3090,524	165,829	290,631	17067,000
F2
r^2	0.892	0.933	0.941	0,973
Slope	0,160	−0,0044	0,047	4,335
Residuals	6712,406	232,986	1824,883	10940,130
F3
r^2	0.901	0.993	0.976	0,982
Slope	0,223	−0,006	0,006	4,809
Residuals	8135,322	66,250	2748,434	13334,530
F4
r^2	0.906	0.982	0.965	0,985
Slope	0,137	−0,003	0,004	3,820
Residuals	7447,240	164,963	3061,446	8386,295
F5
r^2	0.952	0.979	0.972	0,986
Slope	0,116	−0,002	0,002	2,973
Residuals	1471,601	78,476	695,981	5076,589
F6
r^2	0.974	0.989	0.985	0,985
Slope	0,081	−0,001	0,0015	2,037
Residuals	528,153	22,928	322,517	2386,545
F7
r^2	0.981	0.937	0.955	0,891
Slope	0,116	−0,002	0,002	2,651
Residuals	77,762	77,762	201,419	4461,718
F8
r^2	0.916	0.896	0.903	0,838
Slope	0,049	−0,0006	0,0008	1,142
Residuals	141,020	77,222	119,328	881,045
F9
r^2	0.974	0.967	0.970	0,930
Slope	0,034	−0,0004	0,0006	0,846
Residuals	112,881	10,870	94,721	435,761

FIG. 3 Effects of polymer on the bioadhesive strength of the tablets.

FIG. 4 Effects of polymer on the swelling properties of vaginal tablets.

FIG. 5 Sildenafil release from various suppository bases.

FIG. 6 In vitro release of sildenafil from alginate beads and Witepsol H15 suppository bases.

FIG. 7 In vitro release of sildenafil from Eudragit RS100 beads and Witepsol H15 suppository bases and vaginal insert.