Development of Cutaneous Bioadhesive Ureasil-Polyether Hybrid Films

Abstract

The hydrolysis and condensation reactions involved in synthesis of ureasil-polyether films influence the film formation time and the number of chemical groups able to form hydrogen bonds, responsible for the bioadhesion, with the biological substrate. The objective of this work was to study the influence of the use of an acid catalyst (hydrochloric acid) and a basic catalyst (ammonium fluoride) in the hydrolysis and condensation reactions on the time formation and bioadhesion of ureasil-polyether films. The toxicity of the films was evaluated. The MTT assay has shown cell viability of human skin keratinocytes higher than 70% of all analyzed materials suggesting low cytotoxicity. The bioadhesion of the films is strongly dependent on the viscosity and hydrophilic/hydrophobic balance of the polyether chains used to synthetize the hybrid molecules. The use of acid catalyst promotes the formation of less viscous films with higher bioadhesion. The hybrids formed by more hydrophilic PEO chains are more bioadherent, since they can interact more efficiently with the water present in the stratum corneum increasing the bioadhesion. Due to their low toxicity and high bioadhesion, the ureasil-PEO films obtained by using HCl as catalyst agent are good candidates for application to the skin as bioadhesive films.

Tablet of Ximenia Americana L. Developed from Mucoadhesive Polymers for Future Use in Oral Treatment of Fungal Infections

“…With the similar values of MIC in mind, we chose the AMX extract obtained by turbolysis at 50% of EtOH to perform the PAPI-excipient compatibility study because it is a cheaper, faster method and an extractive solution with lower alcohol. The use of ethanol as a solvent is a strategy that follows green chemistry principles, since it is more appropriate biologically and environmentally [ 33 ].…”

“…The cylindrical probe was kept in contact with no force applied for 60 s to ensure intimate contact between the tablet and the mucin disc. After this time, the test was ended at a speed of 1 mm/sec [ 33 , 34 ]. During the experiment, a force-time curve was recorded through the Expert Texture Exponent 32 software (version, Stable Micro Systems, Surrey, UK) and the area under the force-distance curve during the withdrawing phase and peak adhesion was calculated as the work of adhesion (Wad).…”

Study of triamcinolone release and mucoadhesive properties of macroporous hybrid films for oral disease treatment

“…These ureasil-polyether materials have functional groups such as OH that are correlated with mucoadhesive binding to the oral mucosa; the high moisture content favors the formation of hydrogen bonds between water and COOH groups. The choice of Ureasil-PPO400 and Ureasil-PEO500 materials was due to their lower molecular weight in relation to other ureasil-polyethers found in the literature [12,14], resulting in a greater amount of functional groups able to bind to the biological substrate; this is important to maintain film adherence for a long time, while suffering the action of humidity and mucosal movements.…”

Drug Delivery Systems Obtained from Silica Based Organic-Inorganic Hybrids

“…Aiming to improve the characteristics of the ureasil-polyether films, Oshiro-Jr. et al [ 64 ] conducted a study with the purpose to assess the influence of acid (hydrochloric acid) and basic (ammonium fluoride) catalyst in the hydrolysis and condensation reactions occurring on the formation and bioadhesion of ureasil-polyether films. The results reveal the nature of the catalyst influence on the speed and in the mechanism of film formation.…”