Elimination of Terbinafine Hydrochloride Antifungal Drug Traces from Water, Pharmaceutical Formulations and Blood Plasma using Low-Cost Bio and Synthetic Sorbents

Abstract

: Chitosan (CS) biosorbent and polyurethane foam (PUF) synthetic sorbent have been utilized to eliminate terbinafine hydrochloride (TRB HCl) antifungal drug in its pure and pharmaceutical forms from both contaminated aqueous and biological media using a batch process. The experimental conditions for efficient removal of TRB HCl for both CS and PUF were optimized depending on various experimental parameters such as the pH of the solution, contact periods, initial TRB HCl concentration, and sorbents dosage in the solution.

SEM, FT-IR, and XRD characterizations were carried out to study the adsorption of a drug by both sorbents. The optimum conditions for removing TRB HCl by CS and PUF were achieved at a pH of 8.5 and a contact time of 60 min at 250 rpm, using 0.4 g for both sorbents. The measured spectrophotometric absorbance at λ_max of TRB HCl was 242 nm. In addition, the zero-point charge (pHpzc) was determined for the studied sorbents. The pHpzc of the surface of sorbents has shown that electrostatic attraction is one of the mechanisms in TRB HCl sorption. The adsorption process was modeled using the pseudo-first-order, pseudo-second-order, Elovich, and intraparticle diffusion kinetic models. The results indicated that the adsorption of TRB HCl on CS and PUF does follow a pseudo-first-order type of reaction kinetics. The adsorption process was modeled using Langmuir and Freundlich isotherms. The adsorption data found that the Freundlich isotherm model was more suitable for the PUF sorbent, while the Langmuir isotherm model better fit the CS biosorbent.

Evaluation of the experimental data using the Langmuir equation revealed that the maximum adsorption capacities of PUF and CS were 2.807 and 1.2297 mg. g^-1, respectively. The solution was also used to estimate TRB HCl in its pharmaceutical form, and the assessed recoveries were 97.25 and 98.437% for CS and PUF, respectively. The proposed procedure was validated for other complex mediums by removing TRB HCl from spiked human blood plasma. In-silico aquatic toxicity forecast of TRB HCl was also carried out.