[Systemic emulsions. 2. Use of different methods of formulation: the effect of essential oils of thyme on stability].

As part of an ongoing investigation on emulsifying techniques, we studied the influence of different essential oils from Thymus vulgaris on emulsion stability. All four chimiotypes tested (geraniol, linalol, carvacrol, and thymol) caused a marked decrease in stability. This instability cannot be explained by a change in the hydrophilic lipophilic balance since the HLBc of the new oil phase (essential oil + paraffine oil) was not significantly different from that of paraffine alone.

[Emulsion systems. I. Comparison of different formulation methods].

This paper examines different technics of emulsifying systems formulation: those using the research of HLBc and those using the phase diagram. The comparison of these two methods of formulation permits us to describe one method looking for the HLBc of each proportions of the phase diagram. So a volume is determined allowing to choose more securely the surfactants proportions and also to end on surer formulation.

Major isomers of the active ingredient of the sunscreen 5(3,3-dimethyl-2-norbornylidene)-3 pentene-2-one.

Synopsis With high-performance liquid chromatography the three major isomers present in the sunscreen agent, 5(3, 3-dimethyl-2-norbornylidene)-3 pentene-2-one, have been isolated and quantified. Their structures have been determined using mass, infra-red, and NMR spectrometry. Isomères dans le filtre solaire 5(3, 3-dimethyl-2-norbornylidene)-3 pentene-2-one.

Stabilisation of emulsions: influence of hydrophilic colloids.

Synopsis The influence of the following hydrophilic polymers on the stability of emulsions has been studied: sodium carboxymethyl cellulose, hydroxyethyl cellulose, agar-agar, water dispersible clay, and a neutralized polyethylene acid. The oil phases used were paraffin oil, olive oil and a synthetic C(8)-C(12) triglyceride. The other emulsifiers were non ionic-types.