DANIELS, R and BARTA, A (1994) PHARMACOPEIAL CELLULOSE ETHERS AS OIL-IN-WATER EMULSIFIERS .1. INTERFACIAL PROPERTIES. EUROPEAN JOURNAL OF PHARMACEUTICS AND BIOPHARMACEUTICS, 40 (3). pp. 128-133. ISSN 0939-6411,
Full text not available from this repository.Abstract
The interfacial properties of pharmacopoeial cellulose ethers were assessed to identify promising candidates to be used as emulsifiers for oil-in-water emulsions. The cellulose derivatives were: sodium carboxymethyl (SCMC), hydroxyethyl (HEC), hydroxypropyl (HPC), methyl (MC), methylhydroxyethyl (MHEC), and hydroxypropylmethyl (HPMC) cellulose. The polymers were characterised by measuring surface tension, and interfacial tension with medium-chain triglycerides (MCT) and mineral oil (MO). In addition, the adsorption of the cellulose ethers onto MCT drops and hydrophobic silicon dioxide Aerosil R972 was determined quantitatively. Non-ionic cellulose ethers showed a clear positive adsorption at the liquid vapour and the other interfaces. SCMC as a polyelectrolyte showed only marginal interfacial activity. A good correlation was found between the interfacial tension and the adsorbed amount onto hydrophobic silicon dioxide, whereas the correlation between interfacial tension and adsorption onto MCT drops was not even as good. This behaviour is explained by the difference in mobility of polymer molecules adsorbed onto a solid or a liquid. In addition, the lifetime of individual oil drops at a planar oil-water interface was studied. Almost no correlation between the results of these experiments and the others was found. Overall, cellulose ethers containing methoxyl or hydroxypropyl groups seem to be promising candidates as emulsifying agents, whereas the formation of stable emulsion with SCMC and HEC is unlikely.
| Item Type: | Article |
|---|---|
| Uncontrolled Keywords: | ; CELLULOSE ETHERS; INTERFACIAL PROPERTIES; ADSORPTION; INTERFACIAL TENSION; DROP STABILITY; O/W EMULSION |
| Depositing User: | Dr. Gernot Deinzer |
| Last Modified: | 19 Oct 2022 08:40 |
| URI: | https://pred.uni-regensburg.de/id/eprint/53247 |
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