Thermodynamic Study of TiO۲/SBA-۱۶-NH۲ as Drug Delivery System

In this work, thermodynamic parameters related to carbamazepine loading on TiO۲/SBA-۱۶-NH۲ nanocomposites were investigated. Thermodynamic factors were calculated to understandthe loading process. ΔH۰ and ΔS۰ values were obtained from lnKc versus ۱/T data.Thermodynamic values for CBZ drug adsorption on TiO۲/SBA-۱۶-NH۲ were calculated. Thevalues of ΔH°, ΔS° and ΔG° have been determined for the five studied temperatures of ۳۰, ۴۰,۵۰, ۶۰ and ۷۰ ℃. The negative values of ΔG° indicate that the adsorption process on thenanocarrier is spontaneous. It can be seen that the values of ΔG° become very positive withincreasing temperature, therefore, increasing temperature is not always favorable in theadsorption process. The negative values of ΔH° indicated that the adsorption of CBZ on thenanocarrier is an exothermic process. ΔS° values play a vital role in reflecting whether the orderof absorption during the absorption process will become less random ΔS°<۰ or more randomΔS°>۰. In addition, the negative value of ΔS° includes the decrease in the degree of freedom ofCBZ drug inside the solution. Furthermore, the sign of ΔS° indicates whether the adsorptionreaction is an associative or dissociative process. Therefore, given that ΔS° has a negativecharge, it could be an associative mechanism. According to the value of ΔH°, the adsorptionbetween drug and nanocarrier can be classified as physical adsorption. Physical adsorption isbased on weak interactions between the adsorbent and the surface sites of the adsorbent.

کلیدواژه ها:

TiO۲/SBA-۱۶-NH۲ ، Carbamazepine ، Drug loading ، Drug delivery system ، Thermodynamic parameters.