The present research deals with the evaluation of a clinoptilolite-rich rock, occurring in the Nižný Hrabovec deposit (Slovakia), for high-value technological applications based on sorption and in vitro release of nonsteroidal anti-inflammatory drugs (i.e., ibuprofen sodium salt). This georesource was surface modified (SMNZ) using four cationic surfactants. Results demonstrate that ibuprofen sorption is very fast and SMZNs can sorb up to ˜26 mg/g of drug as a function of the type of counterion and morphology of surfactant, as well as the hydrophobicity and molecular structure of the drug. Maximum sorption capacities observed for all SMNZs are fully comparable to other adsorbent carriers usually used for removal of contaminants in wastewaters. Sorption of ibuprofen is controlled by a dual mechanism: external anionic exchange and partition into the hydrophobic portion of the patchy bilayer. A prompt drug release in simulated intestinal fluid (SIF) was also observed, making this natural material also suitable to provide rapid soothing effects in potential pharmacological applications. Comparing the results of this study with other recent investigations, a good technological performance of clinoptilolite-rich rock can be inferred despite the relatively low zeolite content (˜56 wt.%).
Keywords: Bayesian information criterion; Emerging contaminant; Ibuprofen; NSAID; Nižný hrabovec; Non-linear regression; Sips; Surfactant; Toth; Zeolite.
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