In vivostratum corneum distribution of lidocaine, assessed by tape stripping, from a new bioadhesive film

Polycaprolactone fibers with self-assembled peptide micro/nanotubes: a practical route towards enhanced mechanical strength and drug delivery applications

The conjugation between micro/nanotubes of l,l-diphenylalanine and polycaprolactone has led to ductile composite fibers suitable for designing polymer membranes potentially usable as degradable skin patches in drug delivery.

Combining tape stripping and non-invasive reflectance confocal microscopy : an in vivo model to study skin damage

BACKGROUND

Evaluation of (immuno)histological and cell biological changes in damaged skin requires often an invasive skin biopsy, making in vivo models inappropriate to study skin damage. Reflectance confocal microscopy (RCM) might overcome this limitation. Therefore, we evaluated the use of a tape-stripping model in combination with RCM to provide morphological data on skin damage and recovery.

METHODS

In 25 volunteers, a tape-stripping stimulus was applied. The skin was imaged with RCM during 1 week and 3 mm punch biopsies were obtained.

RESULTS

Strong correlations between epidermal thickness determined by RCM and conventional histological measurements were found. RCM thickness measurements correlated well with epidermal proliferation. The 10× or 15× repeated tape-stripping resulted in skin damage similar to acute stripping. Mild repeated tape-stripping showed no skin damage.

CONCLUSION

Overall, we demonstrated that non-invasive RCM in combination with tape-stripping could be used as model to obtain morphological and cell biological data on skin-material interactions.

Polymeric films loaded with vitamin E and aloe vera for topical application in the treatment of burn wounds

Burns are serious traumas related to skin damage, causing extreme pain and possibly death. Natural drugs such as Aloe vera and vitamin E have been demonstrated to be beneficial in formulations for wound healing. The aim of this work is to develop and evaluate polymeric films containing Aloe vera and vitamin E to treat wounds caused by burns. Polymeric films containing different quantities of sodium alginate and polyvinyl alcohol (PVA) were characterized for their mechanical properties and drug release. The polymeric films, which were produced, were thin, flexible, resistant, and suitable for application on damaged skin, such as in burn wounds. Around 30% of vitamin E acetate was released from the polymeric films within 12 hours. The in vivo experiments with tape stripping indicated an effective accumulation in the stratum corneum when compared to a commercial cream containing the same quantity of vitamin E acetate. Vitamin E acetate was found in higher quantities in the deep layers of the stratum corneum when the film formulation was applied. The results obtained show that the bioadhesive films containing vitamin E acetate and Aloe vera could be an innovative therapeutic system for the treatment of burns.

Transdermal absorption enhancement of gel containing elastic niosomes loaded with gallic acid from Terminalia chebula galls

OBJECTIVES

To investigate transdermal absorption enhancement of gel containing elastic niosomes loaded with gallic acid in the semipurified fraction isolated from Terminalia chebula Retz. (Combretaceae) galls.

MATERIALS AND METHODS

Nonelastic and elastic niosomes loaded with gallic acid in pure form or in the semipurified fraction were developed. Rat skin permeation by vertical Franz diffusion cells of gallic acid from various gel formulations containing elastic niosomes loaded with gallic acid or the semipurified fraction was performed.

RESULTS

Elastic and nonelastic niosomes loaded with gallic acid or the semipurified fraction exhibited the mixture of unilamellar and multilamellar structures with negative zeta potential values and in the size range of 200-400 nm. Both loaded elastic and nonelastic niosomes showed good physical and chemical stability for 3 months. The percentages remaining of gallic acid in nonelastic were slightly higher than in elastic niosomes. Both elastic and nonelastic niosomes retarded rat skin permeation of the loaded pure gallic acid, while enhanced the loaded gallic acid in the semipurified fraction. However, elastic niosomes exhibited higher percentages of gallic acid through rat skin than the nonelastic niosomes.

DISCUSSION AND CONCLUSION

This study has demonstrated the potential of niosomes, especially elastic niosomes, for the enhancement of chemical stability and rat skin transdermal absorption of gallic acid in the semipurified fraction from T. chebula galls, which will be beneficial for topical antiaging application.