@misc{9224072,
  abstract     = {{Photodynamic therapy (PDT) is an established treatment for actinic keratosis and selected non-melanoma skin cancers. Still, its broader use is limited by pain, skin irritation, and formulation constraints associated with high photosensitiser concentrations. This study aimed to develop and evaluate a Crystalip®-based topical PDT formulation that enables two-step manufacturing, delivers methyl-aminolevulinate (m-ALA) efficiently, improves oxygen availability, and is scalable compared with current commercial products.
Crystalip® creams based on glycerol monolaurate and glycerol monomyristate were prepared using a two-step hydration process designed to allow incorporation of the heat-sensitive m-ALA after cooling. The effects of heating method, water-addition strategy, and batch scale (10 g–1 kg) on crystal structure and viscosity were investigated using optical microscopy and rheological measurements. m-ALA permeation from Crystalip® creams containing 0.5–1.6 % (w/w) m-ALA was evaluated using Franz diffusion cells and compared with the commercial reference formulation Metvix® (16 % m-ALA). In addition, a catalase-containing Crystalip® formulation was assessed for its ability to enhance oxygen availability using electrochemical measurements with a skin-covered oxygen electrode.
The results showed that Crystalip® creams can be reproducibly manufactured using a two-step hydration process suitable for incorporating heat-sensitive actives. Controlled heating and staged water addition reduced variability in viscosity, and scale-up from 10 g to 1 kg improved formulation homogeneity. Although absolute m-ALA permeation from Crystalip® formulations was substantially lower than from the commercial reference formulation Metvix®, the release kinetics were diffusion-controlled and scaled with m-ALA concentration, indicating a similar underlying release mechanism across formulations. Catalase remained active when incorporated into Crystalip® and increased local oxygen generation.
Overall, the study demonstrates that Crystalip® is a scalable lipid-based platform capable of incorporating m-ALA and catalase, supporting further development of alternative PDT formulations with reduced drug concentrations and improved oxygen availability.}},
  author       = {{Humaloja Skarsten, Madeleine}},
  language     = {{eng}},
  note         = {{Student Paper}},
  title        = {{Exploring the Potential to Improve Photodynamic Therapy of Skin Cancer by Exogenous Catalase and m-ALA Delivery Using a Crystalip® Topical Cream Formulation}},
  year         = {{2026}},
}