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.

Functionalization of hydrocolloids: principal component analysis applied to the study of correlations between parameters describing the consistency of hydrogels.

This work was part of a pure research project on the functionalization of three families of hydrocolloids: cellulose derivatives, carrageenates, and alginates. Principal component analysis (PCA), a powerful statistical method, was used to demonstrate the relations existing among these different parameters that describe the consistency of hydrogels and their spreadability. This approach therefore provides a basis for modeling hydrogel consistency.

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.

Stabilization of Octastatin, a somatostatin analogue: comparative accelerated stability studies of two formulations for freeze-dried products.

Octastatin (vapreotide INN) is a somatostatin analogue being developed in gastro-enterologic, neuroendocrine and oncologic applications. The pharmaceutical form is a freeze-dried preparation for parental injection use. This study was intended to evaluate the stability of the freeze-dried products and to determine the optimally stable formulation.