Effects of terpenes and oleic acid as skin penetration enhancers towards 5-fluorouracil as assessed with time; permeation, partitioning and differential scanning calorimetry

1995 ◽  
Vol 116 (2) ◽  
pp. 237-251 ◽  
Author(s):  
M.A. Yamane ◽  
A.C. Williams ◽  
B.W. Barry
2016 ◽  
Vol 70 (6) ◽  
Author(s):  
Chia-Ching Li ◽  
Li-Huei Lin ◽  
Hsun-Tsing Lee ◽  
Jing-Ru Tsai

AbstractThe present study used differential scanning calorimetry, thermogravimetric analysis, and UV spectrometry to examine: i) the encapsulation of an organic UV filter 1-(4-methoxyphenyl)-3-(4-tert-butylphenyl)propane-1,3-dione (avobenzone) within modified dextrin and ii) the characteristics of these inclusion complexes (MDA). The properties of avobenzone emulsions with and without encapsulation in modified dextrin, the in vitro UV protection factor, dissolution and release, and the skin penetrability of avobenzone were also examined. The presence of inclusion complexes significantly decreased the tendency of the UV filter to penetrate the skin. In addition, such inclusion complexes should effectively prevent skin damage from radiation extending from the UVA to the UVC.


Author(s):  
Pierre A. Hanna ◽  
Mamdouh M. Ghorab ◽  
Shadeed Gad

Introduction: Betamethasone dipropionate is a highly effective corticosteroid anti-inflammatory. However, the main drawback of its topical use is the limited skin penetration into deeper skin layers. Also, its systemic use has shown many side effects. </P><P> Objective: The goal of this research was to formulate betamethasone dipropionate in nanostructured lipid carriers (NLC) formulae that contain oleic acid to aid its penetration to deeper skin layers and to aid absorption to local regions upon topical application. </P><P> Methods: NLC formulae were prepared by high shear homogenization then sonication. Formulae were characterized for their particle size, size distribution, electric potential, occlusion factor, entrapment efficiency, drug loading, transmission electron microscopy, in vitro drug release, and ex vivo skin penetration. Compatibility of ingredients with drug was tested using differential scanning calorimetry. Formulae were shown to have appropriate characteristics. NLC formulae were superior to traditional topical formulation in drug release. </P><P> Results: Upon testing ex vivo skin penetration, betamethasone dipropionate prepared in NLC formulae was shown to penetrate more efficiently into skin layers than when formulated as a traditional cream. NLC formulation that contained higher percentage of oleic acid showed higher penetration and higher amount of drug to pass through skin. </P><P> Conclusion: In general, NLC with lower oleic acid percentage was shown to deliver betamethasone dipropionate more efficiently into deeper skin layers while that of a higher oleic acid percentage was shown to deliver the drug more efficiently into deeper skin layers and through the skin, transdermally.


2018 ◽  
Vol 11 (4) ◽  
pp. 138 ◽  
Author(s):  
Lucia Montenegro ◽  
Francesco Castelli ◽  
Maria Sarpietro

Differential scanning calorimetry (DSC) has emerged as a helpful technique both to characterize drug delivery systems and to study their interactions with bio-membranes. In this work, we compared idebenone (IDE)-loaded solid lipid nanoparticle (SLN) interactions with bio-membranes assessed by DSC with previous in vitro skin penetration data to evaluate the feasibility of predicting IDE skin penetration using DSC analyses. In vitro interactions experiments were performed using multi-lamellar liposomes as a model of bio-membrane. Enthalpy changes (ΔH) and transition temperature (Tm) were assessed during nine repeated DSC scans to evaluate IDE-loaded SLN–bio-membrane interactions over time. Analyzing ΔH and Tm values for each scan, we observed that the difference of ΔH and Tm values between the first and the last scan seemed to be related to SLN ability to locate IDE in the epidermis and in the stratum corneum, respectively. Therefore, the results of this study suggest the possibility of qualitatively predicting in vitro IDE skin penetration from IDE-loaded SLN utilizing the calorimetric parameters obtained from interaction experiments between the carriers under investigation and a model of bio-membrane.


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