(i) grease-ball and (ii) brick dust compounds . The first have a higher logP and are very lipophilic compounds, with lower melting point. The last, "brick dust" compounds (logP < 3) show low solubility in lipid excipients. Despite of that, lipid-based DDS can be successfully used to enhance BTB bioavailability, however studies about the excipients as well as their interactions with the API are necessary .