A series of in vitro and human studies of a novel lip cream formulation for protecting against environmental triggers of recurrent herpes labialis

Abstract

Purpose

These studies describe the testing of a novel, daily-use lip cream designed for individuals with lips prone to recurrent herpes labialis (RHL) that protects against environmental triggers.

Subjects and methods

In vitro occlusive and in vitro and in vivo photoprotection analyses, a characterization of normal vs dry lips, and a randomized, evaluator-blinded, clinical trial that assessed the lip cream in healthy subjects with dry lips were conducted. In the clinical trial, subjects applied the lip cream or were untreated and evaluated using transepidermal water loss (TEWL), corneometry, visual assessments of lip dryness, expert photographic evaluations, and subject-rated outcomes.

Results

The lip cream’s in vitro water vapor transmission rate (84.1 g/(m² h)) indicated moderate occlusivity. The lip cream, but not placebo or control (water), reduced ultraviolet A (UVA)- and UVB-induced DNA damage, and tumor necrosis factor-α (EpiDerm^FT) and pros-taglandin E₂ release (EpiDerm^FT and EpiGingival™). The lip cream’s in vivo sun protection factor (SPF) was 12.2 (lower confidence limit, 11.3) and SPF/UVA protection factor ratio was 0.9. The characterization of dry vs normal lips identified differences in moisturization. In the clinical trial, the lip cream significantly decreased TEWL (difference: −7.19 [95% CI: −11.41, −2.98]; P<0.01), increased corneometry (difference: 4.62 [95% CI: 1.05, 8.19]; P<0.05), and reduced visual dryness (difference: −1.48 [95% CI: 2.24, −0.71]; P<0.001) compared to untreated subjects. Significant benefits were also observed on expert photographic assessments of scaling (difference: −0.89 [95% CI: −1.75, −0.03]; P< 0.05), cupping (difference: −1.50 [95% CI: −2.30, −0.70]; P<0.001), and healthy appearance (difference: −1.44 [95% CI: −2.29, −0.58]; P<0.01); differences in overall healthy appearance were not significant (P=0.51). Subject-rated assessments indicated improvements in cracking, dryness, and flaking in the lip cream group but worsening in untreated subjects.

Conclusion

These studies indicate that this novel, daily-use lip cream protects against UV radiation, drying, and chapping, which are established environmental RHL triggers.

Keywords:

• herpes simplex virus
• barrier function
• lip care
• UV radiation

Supplementary materials

Figure S1 Lip cream with UV filters inhibited UVB DNA damage (CPD, pink staining) and apoptosis (CC3, brown staining) in EpiGingival^™.

Notes: Lip cream with UV filters and without UV filters (placebo) were topically applied 1 hour prior to UVB irradiation (150 mJ/cm²). Non-UVB treatment (untreated) was used as a negative control and baseline. Tissue samples were collected for IHC staining at 6 hours post-UVB (n=3). The images at top panels were scanned at 40× using Nanozoomer (Hamamatsu) and shown at 100%.

Abbreviations: CC3, cleaved caspase-3; CPD, cyclobutane pyrimidine dimers; IHC, immunohistochemical; UVB, ultraviolet B.

Figure S2 Lip cream with UV filters inhibited UVA-induced apoptosis (CC3, brown staining) in EpiGingival^™ at 28 hours post-UVA (50 J/cm²) after UVA irradiation.

Notes: Lip cream placebo is the test formulation without the UV filters. Untreated samples were not applied with any test product (n=3).

Abbreviations: CC3, cleaved caspase-3; UVA, ultraviolet A.

Acknowledgments

The authors wish to thank all of the subjects for their participation and Robert Geske for providing histology support. The authors thank the proDERM Institute for Applied Dermatological Research, Schenefeld/Hamburg, Germany who conducted the in vivo SPF study between January 6 and February 5, 2014. This study was sponsored by GSK Consumer Healthcare. Medical writing assistance was provided by Dennis Stancavish, MA of Peloton Advantage and was funded by GSK Consumer Healthcare. GSK Consumer Healthcare provided a full review of the article.

Disclosure

CFG was an employee of GSK Consumer Healthcare, Wey-bridge, UK at the time of study planning and execution. DJM is an employee of GSK Consumer Healthcare, Wey-bridge, UK. HM and GS are employees of GSK Consumer Healthcare, Warren, NJ, USA. XW is an employee of GSK Consumer Healthcare, Collegeville, PA, USA. AVR is an employee of AVR Consulting, Ltd., Cheshire, UK. CBL was an employee of GSK Consumer Healthcare, Collegeville, PA, USA at the time of study planning and execution. RW is an employee of MedClin Consulting, LLC, Kolkata, India and was an employee of GSK Consumer Healthcare, Warren, NJ, USA at the time of study planning and execution. GG is an employee of cyberDERM, Inc., Broomall, PA, USA.