A study of oleic acid oily base for the tropical delivery of dexamethasone microemulsion formulations

Fluocinolone Acetonide Microemulsion in Combination with a Fractional Laser for the Treatment of Scalp Psoriasis

This study introduces fluocinolone acetonide (FA) microemulsion in combination with ablative fractional lasering as a new effective treatment for scalp psoriasis. A pseudo-ternary phase diagram was constructed using the aqueous titration method. The suitable ratio of surfactant mixture (S_mix):oil mixture (O_mix):water was chosen from the microemulsion region of the diagram. FA was loaded into the selected ratio to prepare FA microemulsion. Ex vivo skin permeation study of the FA microemulsion with fractional laser assistance was performed to determine a proper ablative depth. A pilot clinical study was conducted to evaluate the efficacy of FA microemulsion and FA microemulsion combination with lasering at the optimum ablation depth. The selected microemulsion base contained (in wt%) 77% water, 20% S_mix (Tween 80:ethanol, 2:1), 3% O_mix (10% benzyl benzoate and 1% benzyl alcohol in bergamot oil), and 0.2% sodium carboxymethylcellulose. FA was loaded into this base at a concentration of 0.1%. The skin lasered at an ablation depth of 50 µm was conducted in the pilot clinical study. Scalp psoriasis responded well to the FA microemulsion. Psoriasis scalp severity index (PSSI) scores indicated that the FA microemulsion plus laser treatment provides higher efficacy than the FA microemulsion alone without any topical and systemic side effects. The efficacy of the treatments could be maintained for at least 1 week after treatment discontinuation. FA microemulsion was properly formulated and evaluated. The microemulsion demonstrating the greatest benefits was used in combination with ablative fractional lasering to treat scalp psoriasis.

Preparation and Microstructural Characterization of Griseofulvin Microemulsions Using Different Experimental Methods: SAXS and DSC

Purpose: The objective of the present study is to formulate and evaluate a new microemulsion (ME) for topical delivery of griseofulvin.

Methods: The solubilities of griseofulvin in different combinations of surfactant to co-surfactant (S/Co ratio) were determined. Accordingly, based on their phase diagrams, eight microemulsions were formulated and then evaluated with respect to their particle size, surface tension, viscosity, conductivity, zeta potential and stability. Their release behavior, Scanning Electron Microscopy (SEM), Differential Scanning Calorimetry (DSC), refractory index (RI), pH and Small-angle-X-ray scattering (SAXS) were also assessed.

Results: The results indicated that the mean droplet size of the MEs ranged from 30.9 to 84.3 nm. Their zeta potential varied from -4.5 to -20.8. Other determined characteristics were viscosity: 254-381 cps, pH: 5.34-6.57, surface tension: 41.16- 42.83 dyne.cm^-1, conductivity: 0.0442 – 0.111 ms.cm^-1. The drug release was in the range of 22.4 to 43.69 percent. Also, hexagonal, cubic and lamellar liquid crystals were observed in SAXS experiments.

Conclusion: It can be concluded that any alteration in MEs constituents directly affects their microstructure, shape, droplet size and their other physicochemical properties.