A Comparative Permeation/Release Study of Different Testosterone Gel Formulations

Figures & data

TABLE 1 Composition of different T gels

Gel	Isopropyl alcohol (%w/w)	Asolute alcohol (%w/w)
Gel 0	—	67
Gel 1	1	66
Gel 2	2	65
Gel 5	5	62
Gel 10	10	57

*Gels are named based on the percent IPA. Therefore, Gel x contains x percent w/w IPA.

FIG. 1 In vitro permeation of T from various gel formulations tested on cellulose ester membrane.

TABLE 2 Results of Dunnett's test for comparison of cumulative amount of T permeated different time points from T gels

Formulation	Cumulative amount permeated (μg/cm^2)	|t − c|	Critical value	Conclusion
Cellulose ester membrane
Gel 0	2350.20 ± 333.40	545.60		Different
Gel 1	2452.60 ± 349.40	443.20	464.76	Not different
Gel 2	2587.70 ± 328.80	308.10		Not different
Androgel®	2895.80 ± 254.80	—
Celgard® 2400 membrane
Gel 0	3085.90 ± 145.70	1262.80		Different
Gel 1	3201.20 ± 284.40	1147.50	420.01	Different
Gel 2	3228.20 ± 408.20	1120.50		Different
Androgel®	4348.70 ± 243.80	—
Hairless guinea pig skin
Gel 0	3150.00 ± 977.60	1014.67		Not different
Gel 1	3256.00 ± 744.60	908.67		Not different
Gel 2	3495.20 ± 882.50	669.47	1401.47	Not different
Gel 5	3388.96 ± 796.79	775.71		Not different
Gel 10	3559.70 ± 681.40	604.97		Not different
Androgel®	4164.67 ± 505.84	—

TABLE 3 Results of Dunnett's test for comparison of rate of permeation of T from T gels

Formulation	Rate of permeation (μg/cm^2/hr)	|t − c|	Critical value	Conclusion
Cellulose ester membrane
Gel 0	194.10 ± 29.44	42.46		Different
Gel 1	210.91 ± 16.91	25.65	35.56	Not different
Gel 2	209.82 ± 25.16	26.74		Not different
Androgel®	236.56 ± 19.06	—
Celgard® 2400 membrane
Gel 0	179.20 ± 12.26	73.29		Different
Gel 1	185.28 ± 28.72	67.30	37.24	Different
Gel 2	193.38 ± 31.71	59.20		Different
Androgel®	252.58 ± 25.50	—
Hairless guinea pig skin
Gel 0	94.42 ± 31.20	22.86		Not different
Gel 1	95.63 ± 15.36	21.65		Not different
Gel 2	102.53 ± 22.33	14.75	39.68	Not different
Gel 5	89.31 ± 23.49	27.97		Not different
Gel 10	101.92 ± 24.22	15.36		Not different
Androgel®	117.28 ± 11.63	—

FIG. 2 In vitro permeation of T from various gel formulations tested on Celgard® 2400 membrane.

FIG. 3 In vitro permeation of various T gel formulations tested on hairless guinea pig skin.

TABLE 4 Results of Dunnett's test for comparison of lag time in permeation of T from T gels on hairless guinea pig skin

Formulation	Lag time (hr)	|t − c|	Critical value	Conclusion
Gel 0	8.56 ± 3.07	2.01		Not different
Gel 1	8.70 ± 3.67	2.15		Not different
Gel 2	8.00 ± 2.19	1.45	4.86	Not different
Gel 5	3.68 ± 1.41	2.87		Not different
Gel 10	6.25 ± 2.80	0.30		Not different
Androgel®	6.55 ± 2.26			Not different