Soft-templated mesoporous carbons as potential materials for oral drug delivery

Template-synthesized mesoporous carbons were successfully used in in vitro investigations of controlled delivery of three model drugs, captopril, furosemide, and ranitidine hydrochloride (HCl). Captopril and furosemide exhibited desorption kinetics over 30–40 h, and ranitidine. HCl had a complete release time of 5–10 h. As evident from the slow release kinetics, the mesoporous carbons have excellent potential for the controlled-release media of the specific drugs targeted towards oral delivery. The mesoporous carbons, synthesized from phloroglucinol and lignin, a synthetic and a sustainable precursor, respectively, exhibit BET surface area of 200–400 m2 g−1 and pore volume of 0.2–0.6 cm3 g−1. The synthetic carbon has narrower pore widths and higher pore volume than the renewable counterpart and maintains a longer release time. The release kinetics reveals that the diffusivities of the drugs from carbon media are of equivalent magnitude (10−22 to 10−24 m2 s−1). However, a tailored reduction of pore width in the sorbent reduces the diffusivity of smaller drug molecule by an order of magnitude. Thus, engineered pore morphology, along with its functionalization potential for specific interaction, can be exploited for optimal delivery system of a preferred drug.