Skin healing preparations: compared in vitro diffusion of the active ingredients.

We have developed skin healing preparations based on propolis extract:ointments, emulsions, and transparent oil-water (TOW) gels. The formulations were optimized in terms of macroscopic characteristics including spreadability and penetrability, and limpidity and isotropy for the TOW gels. We describe here the results of a study of in vitro diffusion of the active ingredients, flavonoids, and phenolic acids, from some of the preparations we developed. These results show the influence of the dosage form and the choice of excipients on the release of the active product. The least satisfactory results were obtained for hydrophobic ointments and o/w emulsions. The strongest diffusion was obtained with a TOW gel associating isopropyl palmitate, Eumulgin B3, and Cetiol HE.

Comparative texturometric analysis of hydrogels based on cellulose derivatives, carraghenates, and alginates: evaluation of adhesiveness.

This paper reports a texturometric study of hydrogels based on cellulose derivatives, carraghenates (with or without Na+ or K+), and alginates (associated or not with Ca++). The stiffness, elasticity, and cohesiveness are evaluated and the influence of the nature and the concentration of gelling agent on the adhesiveness, an indicator of bioadhesion, is discussed. The highest adhesiveness values are found among the semi-stiff gels, particularly with those based on either sodium or potassium alginate, or cellulose derivatives. The least satisfactory results are obtained with the formulations associating carraghenates and Na+ or K+.

[Standardization of propolis extract and identification of principal constituents]. / Standardisation d'un extrait de propolis et identification des principaux constituants.

Preparation of a propolis extract was codified, conditions of pulverization, extraction and treatment of the extractive solution are specified. The wounds healing properties of this extract are related to flavonoids and phenolic acids, which were identified by TLC.

[Propolis extract. I. Acute toxicity and determination of acute primary cutaneous irritation index]. / Extrait de propolis: I. Etude de la toxicité aiguë et détermination de l'indice d'irritation primaire cutanée.

In first part, the aim of this work is to study the orally subacute toxicity of a propolis extract on conscious mice. LD50 is more than 7.34 g/kg propolis extract: this product is not toxic. In second part, cutaneous primary irritation of several products: excipients and propolis extract alone or in ointments, is evaluated in the rabbit. The cutaneous reactions after reiterated applications for 14 days are observed. The index of cutaneous primary irritation is calculated by evaluation of the erythematous and oedematous lesions. The propolis extract is non irritant.

[Propolis extract. II. Wound healing the the rat and rabbit]. / Extrait de propolis: II. Etude de la cicatrisation de plaies chez le lapin et chez le rat.

This work is related to wounds healing properties of a propolis extract. In first study on the Albinos Rabbit, the activity of a propolis extract is compared with these of a Peru balsam. Optimal concentrations of them in ointments are evaluated by applications on deep cutaneous scarifications. In order to go further into details, we have chosen in second part, another assay on the Rat, allowing the obtention of deeper wounds; By this way, more complete quantification of retained parameters and a better appraising of the wounds healing process evolution are possible.