Shape of vaginal suppositories affects willingness-to-try and preference

Abstract

HIV and other sexually transmitted infections (STIs) are a global threat to public health that may be countered, in part, by microbicides. A successful microbicide must be both biologically efficacious and highly acceptable to users. Sensory attributes have a direct influence on product acceptability. We created a series of vaginal suppositories appropriate for use as microbicides to investigate the influence of shape on women's willingness-to-try. The influence of perceived size and firmness on acceptability was also assessed. Sexually-active women (n=99) were invited to participate in an evaluation of vaginal suppositories in 5 different shapes including: Bullet, Long Oval, Round Oval, Teardrop and Tampon. The volume (3 ml) and formulation for these 5 prototypes were identical. After manipulating prototypes ex vivo (in their hands), participants rated their willingness-to-try on a 100-point visual analog scale. The appropriateness of size and firmness were evaluated using 5-point just-about-right (JAR) scales. Each participant evaluated all 5 prototypes individually. Samples were presented in a counterbalanced monadic sequence using a Williams design. Mean willingness-to-try varied by shape, with Bullet and Long Oval receiving significantly higher scores. This was consistent with JAR data for size, as 70 and 65% of women indicated these shapes were `just-about–right', respectively. In contrast, a minority of women endorsed the other 3 shapes as having a size that was `just-about-right'. The proportion of women who felt the firmness was `just-about-right' was uniformly high, irrespective of shape, suggesting prior attempts to optimize the formula were successful. Perceptions of size and firmness were influenced by the physical length and width of the prototypes, in spite of having constant volume. Women showed high willingness-to-try when asked to assume they were at risk. These results are relevant for behavioral and formulation scientists working on microbicides, to better understand the influence of sensory attributes on acceptability, as acceptability and compliance ultimately impact effectiveness.

Innovative sensory methods to access acceptability of mixed polymer semisoft ovules for microbicide applications

“…Women (Test 1: n = 99 and Test 2: n = 94) were recruited as described elsewhere [36, 37] to evaluate prototypes ex vivo (in their hands) at the Sensory Evaluation Center at Penn State. All participants met the following criteria for inclusion: a) female; b) between 18 and 55 years of age; c) reported having had vaginal sex with a man in the last 12 months; d) were willing to manipulate prototypes with their hands and evaluate them using a computer-guided assessment in an isolated test booth.…”

“…Prior to sample evaluation, participants were asked to watch a 90s video in which a female physician demonstrates how a participant should evaluate a prototype in her hand [36, 37]. Participants were instructed to: 1.…”

“…Appropriateness of firmness was assessed using 5-point categorical just-about-right (JAR) scale. (Standard practice is to collect ‘overall liking’ ratings along with JAR data [39]; however in our previous microbicide studies, willingness-to-try has been consistently used in place of liking [36]). After various ratings were obtained for each sample, women were asked to rank all four suppositories in order from most to least preferred.…”

Vaginal suppositories containingLactobacillus acidophilus: development and characterization

“…Prepared suppositories had bullet shape, as shown in Figure 1, as this shape is considered preferable by women 33 . The results obtained with MTS assays, and the values of cytotoxicity concentration 50 (CC 50 ) are summarized in Figure 2, according to the different vaginal cell lines used.…”

On-demand microbicide products: design matters

“…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]. In a preceding focus group study, the authors identified that most women preferred a long oval and bullet shape compared to tear drop, tampon, or round oval shapes [62]. By systematically varying the size (1, 3, and, 5 g) and firmness as measured by storage modulus, nine different products were prepared.…”