Approval Date: July 14, 1998

Freedom of Information Summary
NADA 009-576

I. GENERAL INFORMATION:

NADA	009-576
Sponsor:	Fort Dodge Animal Health 9401 Indian Creek Parkway Overland Park, KS 66210
Generic Name:	estradiol benzoate and progesterone
Trade Name:	Synovex® C and Synovex® S
Marketing Status:	Over the Counter (OTC)
Effect of Supplement:	This supplement provides for the implantation of Synovex C in steers fed in confinement for slaughter when used as part of a reimplant program where Synovex S is implanted at approximately day 70 after the initial implantation of Synovex C.

II. Indications For Use

SynovexÒ C
SynovexÒ C is recommended for use in suckling beef calves up to approximately 400 pounds of body weight. SynovexÒ C is also recommended for improvement in rate of weight gain in steers weighing greater than 400 pounds and fed in confinement for slaughter when used as part of a re-implant program in which an initial SynovexÒ C implant is followed at approximately 70 days by SynovexÒ S.

SynovexÒ S
For increased rate of weight gain and improved feed efficiency. For additional improvement in rate of weight gain in steers fed in confinement for slaughter, SynovexÒ S may be used as part of a re-implant program where an initial SynovexÒC or SynovexÒ S implant is followed by SynovexÒ S at approximately 70 days.

III. DOSAGE:

A.	DOSAGE FORM	Implantation.
B.	ROUTE OF ADMINISTRATION	Subcutaneous implantation on the posterior aspect of the middle one-third of the ear by means of an implant gun.
C.	RECOMMENDED DOSAGES:	SynovexÒ C: One implant containing 100 mg progesterone and 10 mg estradiol benzoate. SynovexÒ S: One implant containing 200 mg progesterone and 20 mg estradiol benzoate. May be re--implanted at approximately 70 days.

IV. Effectiveness

Effectiveness is established by data in the parent application. Therefore, no further studies were required.

V. Target Animal Safety

Target animal safety is established by data in the parent application. Therefore, no further studies were required.

VI. Human Safety

Human safety is established by data in the parent application. Therefore, no further studies were required.

VII Agency Conclusions

Adequate data demonstrates the safe and effective use of SynovexÒ C and SynovexÒ S for additional improvement in rate of weight gain when administered to steers fed in confinement for slaughter.

Under the Center's supplemental approval policy (21 CFR 514.106(b)(2)), this is a Category II change providing for the implantation of SynovexÒ C in steers fed in confinement for slaughter when used as part of a reimplant program where SynovexÒ S is implanted at approximately day 70 after the initial implantation of SynovexÒ C. The approval of this change is not expected to have any adverse effect on the safety or effectiveness of this new animal drug. Accordingly, this approval did not require a reevaluation of the safety and effectiveness data in the parent application.

VIII. Labeling

Two (2) pages of labeling are attached as follows:
1. SynovexÒ S 10 Cartridge Box Label
2. SynovexÒ C 10 Cartridge Box Label

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