title: Coprecipitation of nonoxynol-9 with polyvinylpyrrolidone to decrease vaginal irritation potential while maintaining spermicidal potency.
abstract: The aim of this study was to test the hypothesis that polyvinylpyrrolidone (PVP) would increase the critical micelle concentration (CMC) of nonoxynol-9 (N-9), providing a reduction in its irritation potential, while maintaining essential spermicidal activity. Solid coprecipitates of N-9 with PVP were manufactured with the use of a modified lyophilization process. The irritation potential of N-9 was estimated by an in vitro assay, monitoring the extent of hemolysis of red blood cells. CMCs of N-9 were measured in the presence of various concentrations of PVP. A modified Sander-Cramer assay was implemented to measure the spermicidal activity of N-9 and the N-9/PVP coprecipitates. With the use of the lyophilization process and more suitable solvents, solid coprecipitates of N-9/PVP were manufactured with no residual organic solvents. The irritation potential of N-9 was reduced when in the presence of PVP-50% hemolysis values increased from 0.054 mM to more than 0.2mM. N-9 CMC values increased in the presence of PVP from 0.085 mM (0% PVP) to 0.110 mM (3.5% PVP) and 0.16 6mM (10% PVP). However, spermicidal activities ranged from 0.213 mM to 0.238 mM, N-9 remaining steady regardless of the amount of PVP. By use of N-9/PVP coprecipitates, the self-association properties and irritation potentials of N-9 were altered. This result suggests a process to produce a spermicidal product that reduces the detrimental implications to the vaginal epithelium while maintaining the essential spermicidal activity.
authors: Division of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, Lexington, KY, USA.
authors: Philip T
authors: PT
authors: Fowler
authors: Gustavo F
authors: GF
authors: Doncel
authors: Paul M
authors: PM
authors: Bummer
authors: George A
authors: GA
authors: Digenis
mesh_terms: D000818:Animals; D001681:Biological Assay; D011232:Chemical Precipitation; D004285:Dogs; D004912:Erythrocytes / Q000187:drug effects; D005260:Female; D006461:Hemolysis / Q000187:drug effects; D006801:Humans; D007509:Irritants / Q000008:administration & dosage / Q000009:adverse effects / Q000037:antagonists & inhibitors; D008297:Male; D008823:Micelles; D017137:Nonoxynol / Q000008:administration & dosage / Q000009:adverse effects / Q000737:chemistry*; D010592:Pharmaceutic Aids / Q000737:chemistry / Q000627:therapeutic use; D011205:Povidone / Q000737:chemistry* / Q000627:therapeutic use; D013089:Spermatocidal Agents / Q000008:administration & dosage / Q000009:adverse effects / Q000737:chemistry; D013094:Spermatozoa / Q000378:metabolism; D014627:Vaginitis / Q000209:etiology / Q000517:prevention & control
chemical_list: D007509:Irritants; D008823:Micelles; D010592:Pharmaceutic Aids; D013089:Spermatocidal Agents; D017137:Nonoxynol; D011205:Povidone