Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 2 de 2
Filter
Add more filters










Database
Language
Publication year range
1.
Int J Pharm ; 476(1-2): 134-41, 2014 Dec 10.
Article in English | MEDLINE | ID: mdl-25269010

ABSTRACT

This work examines the influence of essential oil composition on emulsification with rhamnolipids and their use as therapeutic antimicrobial agents against two opportunistic pathogens, methicillin-resistant Staphylococcus aureus (MRSA) and Candida albicans. Rhamnolipids, produced by Pseudomonas aeruginosa, with waste frying oil as the carbon source, were composed of eight rhamnolipid homologues. The rhamnolipid mixture was used to produce emulsions containing essential oils (EOs) of Melaleuca alternifolia, Cinnamomum verum, Origanum compactum and Lavandula angustifolia using the titration method. Ternary phase diagrams were designed to evaluate emulsion stability, which differed depending on the essential oil. The in vitro antimicrobial activity of the EOs alone and the emulsions was evaluated. The antimicrobial activity presented by the essential oils alone increased with emulsification. The surface properties of rhamnolipids contribute to the positive dispersion of EOs and thus increase their availability and antimicrobial activity against C. albicans and S. aureus. Therefore, rhamnolipid-based emulsions represent a promising approach to the development of EO delivery systems.


Subject(s)
Anti-Bacterial Agents/pharmacology , Antifungal Agents/pharmacology , Glycolipids/chemistry , Oils, Volatile/chemistry , Anti-Bacterial Agents/chemistry , Antifungal Agents/chemistry , Candida albicans/drug effects , Drug Delivery Systems , Drug Stability , Emulsifying Agents/chemistry , Emulsions , Methicillin-Resistant Staphylococcus aureus/drug effects , Pseudomonas aeruginosa/metabolism
2.
J Colloid Interface Sci ; 394: 337-45, 2013 Mar 15.
Article in English | MEDLINE | ID: mdl-23245883

ABSTRACT

High kinetic stability water-in-oil high internal phase ratio emulsions (W/O-HIPREs) have been obtained in a 0.5% Theophylline (TP) aqueous solution/Cremophor WO7/liquid paraffin system at 25 °C. The release of TP has been studied from HIPREs with pH values of the dispersed phase ranging between 2 and 12. Although the release from aqueous solutions was not influenced by pH, the release from HIPREs depended strongly on the pH of the dispersed phase. Increasing the solubility of TP in the dispersed phase, its apparent diffusion coefficient decreased over two orders of magnitude. Two different physico-chemical models have been applied to describe the diffusion of TP, showing an excellent agreement with experiments and confirming the role of the structure of the emulsions and the solubility of the drug. It has been shown that only non-ionized species are able to cross the interfacial film. Therefore, at pH>pKa diffusion is limited by the concentration of non-ionized species inside the emulsion droplets, while at pH

Subject(s)
Bronchodilator Agents/administration & dosage , Delayed-Action Preparations/chemistry , Emulsions/chemistry , Theophylline/administration & dosage , Diffusion , Hydrogen-Ion Concentration , Mineral Oil/chemistry , Polyethylene Glycols/chemistry , Solubility
SELECTION OF CITATIONS
SEARCH DETAIL
...