title: Contraception by Ushercell (cellulose sulfate) in formulation: duration of effect and dose effectiveness.
abstract: This study evaluated contraception by formulated Ushercell, a uniquely high-molecular-weight form of cellulose sulfate, in the rabbit. Variables included (1) dose effectiveness, (2) duration of effectiveness, and (3) formulation excipients. Vaginally applied carboxymethyl-cellulose-based Ushercell gel is contraceptive. A 6% gel is active for at least 18 h; partial activity is observed for at least 24 h. With an application-insemination interval of 0.5 h, Ushercell as low as 0.1% is contraceptive. Contraception is incomplete with 2% Ushercell and an application-insemination interval of 24 h. Ushercell formulations containing a relatively high concentration of Carbopol are ineffective contraceptives, whether the gel is applied before insemination or is premixed with spermatozoa before insemination. Contraceptive activity is restored in Ushercell formulations with lower Carbopol content. This study shows that formulated Ushercell is an effective, long-lasting contraceptive and, hence, is bioavailable when vaginally applied. Activity is dependent on the type and relative concentration of formulation excipients. These data support a projected successful outcome of further clinical trials.
authors.affiliation: Department of Obstetrics and Gynecology, Rush University Medical Center, Chicago, IL 60612, USA. robertan@corecomm.net
authors.forename: Robert A
authors.initials: RA
authors.lastname: Anderson
authors.forename: Kenneth
authors.initials: K
authors.lastname: Feathergill
authors.forename: Xiao-Hui
authors.initials: XH
authors.lastname: Diao
authors.forename: Calvin
authors.initials: C
authors.lastname: Chany
authors.forename: William F
authors.initials: WF
authors.lastname: Rencher
authors.forename: Lourens J D
authors.initials: LJ
authors.lastname: Zaneveld
authors.forename: Donald P
authors.initials: DP
authors.lastname: Waller
mesh_terms: D000282:Administration, Intravaginal; D000818:Animals; D000890:Anti-Infective Agents / Q000008:administration & dosage*; D002482:Cellulose / Q000008:administration & dosage* / Q000031:analogs & derivatives*; D002626:Chemistry, Pharmaceutical; D003271:Contraceptive Agents, Female / Q000008:administration & dosage*; D004305:Dose-Response Relationship, Drug; D004338:Drug Combinations; D005260:Female; D007315:Insemination, Artificial; D011817:Rabbits
chemical_list: D000890:Anti-Infective Agents; D003271:Contraceptive Agents, Female; D004338:Drug Combinations; D002482:Cellulose; C020254:cellulose sulfate