Quantitative perceptual differences among over-the-counter vaginal products using a standardized methodology: implications for microbicide development

Abstract

Background Increasing prevalence of HIV infection among women worldwide has motivated the development of female-initiated prevention methods, including gel-based microbicides. User acceptability is vital for microbicide success; however, varying cultural vaginal practices indicate multiple formulations must be developed to appeal to different populations. Perceptual attributes of microbicides have been identified as primary drivers of acceptability; however, previous studies do not allow for direct comparison of these qualities between multiple formulations. Study Design Six vaginal products were analyzed ex vivo using descriptive analysis. Perceptual attributes of samples were identified by trained participants (n=10) and rated quantitatively using scales based on a panel-developed lexicon. Data were analyzed using two-way ANOVAs for each attribute; product differences were assessed via Tukey’s honestly significant difference test. Results Significant differences were found between products for multiple attributes. Patterns were also seen for attributes across intended product usage (i.e., contraceptive, moisturizer or lubricant). For example, Options© Gynol II® (Caldwell Consumer Health, LLC) was significantly stickier and grainier than other products. Conclusions Descriptive analysis, a quantitative approach that is based on consensus lexicon usage among participants, successfully quantified perceptual differences among vaginal products. Since perceptual attributes of products can be directly compared quantitatively, this study represents a novel approach that could be used to inform rational design of microbicides.

On-demand microbicide products: design matters

“…Color, taste, shape, physical form, odor, and tactile properties of a product can influence user perception [60, 61]. Tactile properties, loosely described as “feel”, encompass attributes such as product firmness, texture, stickiness, and slipperiness [60].…”

“…Tactile properties, loosely described as “feel”, encompass attributes such as product firmness, texture, stickiness, and slipperiness [60]. Hayes and colleagues measured ex vivo acceptability of oval-shaped products (ovules) or suppositories and a hypothetical applicator by assessing user willingness-to-try, perceived effectiveness, and imagined ease of insertion [61].…”

Acceptability in microbicide and PrEP trials

“…However, one can summarize components of the study designs and make some general statements about findings:

Only seven of the 18 papers[12*, 17*, 19, 21, 26, 27, 29] investigate acceptability of actual candidate products. Eight papers [15, 16, 18*, 20, 22-24, 30] examine hypothetical acceptability— typically investigating whether respondents would be willing to use a product, and attitudes and beliefs about the hypothetical product.

Three of the 18 [13*, 25, 28], examine acceptability of a placebo or proxy product focusing on product attributes.Three of the 18 [12*, 19, 28*] ask participants to compare multiple products or dosing regimens and indicate their preference, rather than to evaluate a single product or individual features of a product.To the extent that an overall measure of acceptability is included in studies, the proportion of participants who indicate a “willingness to use” the product is the most common summary construct. Fifteen publications [13*, 15, 16, 17*, 18*, 19-24, 26, 27, 28*, 30] contain such a measure with some variability in responses; in five [13*, 15, 22, 27, 28*] of the 15 studies at least 80% expressed a willingness to use.…”

“…Three of the 18 [13*, 25, 28], examine acceptability of a placebo or proxy product focusing on product attributes.…”

Designing Preclinical Perceptibility Measures to Evaluate Topical Vaginal Gel Formulations: Relating User Sensory Perceptions and Experiences to Formulation Properties

“…37 We demonstrate that similar conceptualizations and methods can be used to evaluate pericoital topical vaginal microbicides. 38 Rheological and other biophysical properties, and product performance attributes that depend upon them (e.g., shear stresses on tissue surfaces, rates of formulation spreading), can be objectively considered in relation to physical sensations and user experiences. These formulation properties and performance characteristics are under the direct control of developers.…”