CLAY MINERALS FOR DRUG DELIVERY SYSTEMS: A SOLID STATE NMR STUDY OF TWO FORMULATIONS WITH IBUPROFEN

Solid oral dosage forms are the leading marketed formulations because of the superior patient compliance and higher active pharmaceutical ingredient (API) stability. Nevertheless, when dealing with solid drugs solubility and dissolution rate play a fundamental role in biopharmaceutics, and they often represent limiting factors that can compromise the desired therapeutic effect. One of the promising strategies to design drug delivery systems with improved release properties is the use of tubular or lamellar inorganic materials able to host APIs into nanometric galleries or pores in non-crystalline state [1]. In this way rapid dissolution can occur after the contact with the dissolution medium, without the need of a previous modification of the API chemical structure [2]. In this work, we investigated two different composites, containing ibuprofen as guest API and Hallosites NanoTubes (HNT) [3] or Hydrotalcite (HTlc) anionic clays [4,5] as inorganic hosts, by exploiting different of solid state NMR experiments, including 1H and 13C MAS spectra and variable temperature T1 relaxation measurements. The comparison of spectral and relaxation properties of the composites with respect to those of the pure components allowed interesting differences, especially on the dynamics of ibuprofen, to be highlighted and discussed. References [1] Van den Mooter, G. The use of amorphous solid dispersions: A formulation strategy to overcome poor solubility and dissolution rate. Drug Discovery Today: Technol. 2012, 9, e79-e85. [2] Perioli, L.; Pagano, C. Inorganic matrices: an answer to low drug solubility problem. Expert Opin. Drug Delivery 2012, 9, 1559-1572. [3] Hanif, M.; Jabbar, F.; Sharif, S.; Abbas, G.; Farooq, A.; Aziz, M. Halloysite nanotubes as a new drug-delivery system: A review. Clay Minerals, 2016, 51, 469-477. [4] Mishra, G.; Dash, B.; Pandey, S. Layered double hydroxides: A brief review from fundamentals to application as evolving biomaterials. Applied Clay Sciece, 2018, 153, 172-186. [5] Carignani, E.; Borsacchi, S.; Blasi, P.; Schoubben, A.; Geppi, M. Dynamics of Clay-Intercalated Ibuprofen Studied by Solid State Nuclear Magnetic Resonance. Molecular Pharmaceutics, 2019, 16, 2569-2578 State Nuclear Magnetic Resonance. Molecular Pharmaceutics, 2019, 16, 2569-2578