Encapsulation of the UV filters ethylhexyl methoxycinnamate and butyl methoxydibenzoylmethane in lipid microparticles: effect on in vivo human skin permeation.

Background: Lipid microparticles loaded with the UVB filter ethylhexyl methoxycinnamate (EHMC) and the UVA filter butyl methoxydibenzoylmethane (BMDBM) were evaluated for their effect on the sunscreen agent's percutaneous penetration.

Methods: Microparticles loaded with EHMC or BMDBM were prepared by the melt emulsification technique using stearic acid or glyceryl behenate as lipidic material, respectively, and hydrogenate phosphatidylcholine as the surfactant. Nonencapsulated BMDBM and EHMC in conjunction with blank microparticles or equivalent amounts of the 2 UV filters loaded in the lipid microparticles were introduced into oil-in-water emulsions and applied to human volunteers.

Solid lipid microparticles for the stability enhancement of a dopamine prodrug.

The oral or peripheral administration of dopamine for the treatment of Parkinson's disease is hampered by its extensive metabolism and inability to cross the blood-brain barrier. Consequently, the enhancement of dopamine stability in physiologic environments and its brain targeting appear useful in formulation development. We propose the preparation and characterization of solid lipid microparticles based on tristearin as a sustained delivery system for dopamine.

Photostabilization effect of quercetin on the UV filter combination, butyl methoxydibenzoylmethane-octyl methoxycinnamate.

The aim of the study was to investigate the effect of the natural antioxidant quercetin on the photostability of the most widely used combination of UVA (320-400 nm) and UVB (290-320 nm) filters, respectively butyl methoxydibenzoylmethane (BMDBM) and octyl methoxycinnamate (OMC). In order to reproduce the conditions prevalent in commercial sunscreen products, the stabilizing efficacy of quercetin was evaluated in model creams containing BMDBM (3%, wt/wt) together with OMC (4%, wt/wt) and exposed to a solar simulator at an irradiance corresponding to natural sunlight. Quercetin was found to enhance the photostability of the two UV filters in a concentration-dependent way.

Solid lipid budesonide microparticles for controlled release inhalation therapy.

A solid lipid microparticle system containing budesonide was prepared by oil in water emulsification followed by spray drying. The solid lipid system was studied in terms of morphology, particle size distribution, crystallinity, thermal properties, aerosol performance, and dissolution/diffusion release. The microparticle system was also compared to conventional spray-dried crystalline and amorphous budesonide samples.

Comparative evaluation of different substrates for the in vitro determination of sunscreen photostability: spectrophotometric and HPLC analyses.

Polymethylmethacrylate (PMMA) plates and Transpore(TM) tapes were compared as substrates for the in vitro evaluation of photostability of commercial sunscreen products. The sun care preparations were applied respectively on Transpore(TM) tapes and PMMA plates and their sun protection factors (SPF) and UVA protection parameters [UVA/UVB ratio, critical wavelength, UVA protection factor (UVA-PF)] were measured by transmission spectroscopy, before and after irradiation with simulated sunlight. No significant differences were observed in the UV protection parameters measured on Transpore(TM) tapes or PMMA plates, before exposure to the solar simulator.