Mucoadhesive Interpolyelectrolyte Complexes for the Buccal Delivery of Clobetasol

This work aimed to investigate the feasibility to design: (a) a mucoadhesive interpolyelectrolyte complex (IPEC) loaded with clobetasol propionate (CP) intended to treat oral lichen planus and (b) individuate an orodispersible dosage form suitable for its administration. IPECs were synthesized by mixing Eudragit\uae E PO (EPO) and different grades of cross-linked polyacrylate derivatives, in different molar ratios, namely 1:1, 1:2, and 2:1. All IPECs resulted at nanoscale independently of their composition (120\u2013200 nm). Both zeta-potentials (\u3b6) and mucoadhesive performances were influenced by the ratio between polymers. On the bases of the preliminary data, IPECs made of Polycarbophil and EPO in the 1:2 ratio were loaded with CP. The encapsulation efficiency was up 88% independently of the CP-IPEC ratio. The drug encapsulation caused IPEC destabilization in water, as it was noticed by the increase of \u3b6 values and the formation of aggregates. Oral lyophilisates were prepared by freeze-drying slurries made of placebo or CP loaded IPECs, maltodextrin with a dextrose equivalent 38 and Span\uae80. The optimized formulation permitted to obtain a fast disintegration upon contact with water reducing the tendency of IPECs to aggregate. Moreover, oral lyophilisates allowed improving the apparent solubility of CP throughout the in vitro release experiment

Synthesis of Bifunctional Derivatives of Calix[4]arene Bearing Azidoalkyl Fragments in Cone Stereoisomeric Form

© 2020, Pleiades Publishing, Ltd. Abstract: A procedure for the chloromethylation of lipophilic distally di-O-substituted calix[4]arene derivatives has been developed to prepare dichloromethyl derivatives of calix[4]arenes with long-chain alkyl fragments in cone configuration in high yields. From the chloromethylated derivatives, ammonium/imidazolium salts containing azidopropyl moieties have been synthesized in high yields. The structure of all obtained compounds has been established by 1D and 2D NMR, IR spectroscopy, and MALDI spectrometry. They can be further used as precursors of polytriazole/polyimidazole polymer species as promising carriers for metal-complex catalysis