Arxada Piroctone Olamine

Lonza’s newest antidandruff active, PO.FreshTM (piroctone olamine) active (Fig.1), works to treat dandruff at the root cause by functioning as a fungicide with specific efficacy against Malassezia.

Antifungal Efficacy

The antifungal potential of PO.FreshTM active against Malassezia furfur was evaluated using standard methodology, showing a minimum inhibitory concentration (MIC) against M. furfur of 16 ppm. Further, suspension-based tests were performed to evaluate the performance of PO.FreshTM in several common surfactant systems. Results show quick kill in a standard SLES shampoo surfactant system (Fig. 2). There is an approximately 5 log10 reduction in the M. furfur population within 4 hours contact time.

Figure 2
Efficacy of 1% PO.FreshTM in an SLES surfactant system. Kill rate of M. furfur calculated as Log10 reduction in population after 2-24 hours contact time.

Clinical Efficacy

Efficacy of PO.FreshTM active was further assessed in vivo over a period of 28 days, in a double-blind, randomized study. A group of 32 subjects, male and female, with ages ranging from 25 to 59, were included in the study if their total dandruff score was ≥4 on a scale of 0-10. They applied a shampoo containing 1% PO.FreshTM active at least 3 times per week, and their dandruff was clinically assessed once per week.

The formulation containing PO.FreshTM active was well tolerated, and no sensations of discomfort were reported by the study subjects. Clinical assessment of total dandruff showed a significant decrease, versus the baseline (D1) evaluation, starting at day 8, and continuing through the length of the study. This significant decrease was also evident when examining non-adherent and adherent dandruff separately (Fig. 3).

Figure 3
In vivo efficacy of PO.FreshTM active shampoo. The mean scores for total, adherent and non-adherent dandruff are shown. Significance was calculated using a Dunnett t (2
sided) comparison and differences were considered significant at p<0.05.

The clinical results were mirrored by subject self-assessment of their dandruff (Fig. 4). Subjects were asked to assess their dandruff on a scale from 1 to 10. A significant effect on dandruff was perceived by the panelists beginning with day 8, the first evaluation after study initiation. As in the clinical assessment, the self-perceived amount of dandruff continued to decrease through the duration of the study.as well as a significant decrease in self-assessed dandruff and itching scores that persisted through the end of the study.

Figure 4
Self-assessment of dandruff and efficacy of 1% PO.FreshTM active shampoo. Assessment on an ordinal scale of 1 (no dandruff) to 10 (very abundant dandruff). The mean scores for dandruff are shown. Significance was calculated using a Dunnett t (2 sided) comparison and differences were considered significant at p<0.05.

Subjects were also asked to assess scalp itch during the study, on a scale of 1 to 10. A significant decrease in itch, versus study start, was observed starting with the first assessment date on D8 of the study (Fig.5). The mean itch level continued to decrease through the length of the study.

Figure 5
Self-assessment of itch with application of 1% PO.FreshTM active shampoo. Assessment on an ordinal scale of 1 (no itching) to 10 (very strong itching). The mean scores for itch are shown. Significance was calculated using a Dunnett t (2 sided) comparison and differences were considered significant at p<0.05.

Regular application of a shampoo containing 1% PO.FreshTM active was well tolerated and showed clinical efficacy against total, non-adherent and adherent dandruff. This efficacy was perceivable by study subjects in dandruff level as well as scalp itch.