Monitoring of the interaction of calcium phosphate cement and lidocaine hydrochloride by electrochemical impedance spectroscopy during the drug release process.

Developments aimed at expanding knowledge in the health area make it possible to increase human life expectancy. Calcium phosphate cement is a good option as a carrier for drug delivery systems because it is possible to achieve biocompatibility and adequate porosity in the same material. Utilization of this ceramic matrix is necessary to control the drug dosage released during contact between the bioceramic and host organism, and to promote bone regeneration. The techniques currently used to calculate the amount of drug released from the calcium phosphate cement in a drug delivery test have some drawbacks, such as limited sensitivity and loss of sample during measurements. Considering the reduction of the amount of sample used to determine the percentage of drug released and the use of a non-destructive technique with high sensitivity, the proposed work uses electrochemical impedance spectroscopy as a method to determine the phenomenon of interaction between the drug and the matrix. The matrix immersed on the phosphate buffer solution (PBS) is calcium phosphate cement with 1% of lidocaine hydrochloride. The results show changes in the R(RQ)(RQ)(RQ) equivalent circuit values obtained by the Nyquist diagrams of the samples that had their resistance values elevated due to the interaction between the drug and PBS/calcium phosphate cement, which causes correlation between the drug released presented on the PBS and variation in the electrical properties of the system. [ABSTRACT FROM AUTHOR]