Formulation of casein hydrogels

Protein-based hydrogels have gained considerable interest due to their properties such us biocompatibility, nontoxic, biodegradability, renewable, inexpensive and easy to obtain. Hydrogel properties depend on temperature, polymer concentration, pH, crosslinking levels, salt concentrations and aging. Casein is a natural protein present in the bovine milk (about 80%) which exists in the form of various micelles, it is composed of α-s1, α-s2, and β- and κ-casein and tends to self-assembly. Casein based hydrogels are suitable for use in biomedical applications. Considering their potential applications in the field of medicine, in this work, we have the objective to find the best conditions to development a casein hydrogel with tetracaine hydrochloride such active compound. The tetracaine hydrochloride has anesthetic properties so would allow a painless and comfortable treatment for the patient. So, different hydrogel formulations were proposed. The selected components were casein, glycerol, tetracaine hydrochloride, potassium carbonate and sodium alginate. Stability test, apparent density, pH, moisture content and swelling test were investigated. The formulation that allowed us to obtain a hydrogel with the desired properties was composed of tetracaine hydrochloride 1%, casein 2%, glycerol 50%, sodium alginate 4% and potassium carbonate solution 18% (The percentages are expressed on a casein basis). Casein hydrogel showed potential for use as anesthetic in medicine.