RESUMEN
This work was aimed to develop levodopa (L-dopa) nasal powder to achieve controllable drug release and high nasal deposition efficiency. A series of uniform microparticles, composed of amorphous L-dopa and excipients of hydroxypropyl methyl cellulose (HPMC), polyvinylpyrrolidone (PVP), or hydroxypropyl-ß-cyclodextrin (CD), were fabricated by a self-designed micro-fluidic spray dryer. The effects of excipient type and drug/excipient mass ratio on the particle size, morphology, density, and crystal property, as well as the in vitro performance of drug release, mucoadhesion, and nasal deposition, were investigated. Increased amounts of added excipient, regardless of its type, could accelerate the L-dopa release to different extent. The addition of CD showed the most obvious effect, i.e., ~83% of L-dopa released in 60 min for SD-L1CD2, compared to 37% for raw L-dopa. HPMC could more apparently improve the particle mucoadhesion than PVP and CD, with respective adhesive forces of ~269, 111, and 26 nN for SD-L1H2, -L1P2, and -L1CD2. Nevertheless, the deposition fractions in the olfactory region for such samples were almost the same (~14%), probably ascribable to their quite similar particle aerodynamic diameter (~30 µm). This work demonstrates a feasible methodology for the development of nasal powder.
RESUMEN
Nowadays, the buccal administration of mucoadhesive films is very promising. Our aim was to prepare ascorbic acid-containing chitosan films to study the properties and structures important for applicability and optimize the composition. During the formulation of mucoadhesive films, chitosan as the polymer basis of the film was used. Ascorbic acid, which provided the acidic pH, was used in different concentrations (2-5%). The films were formulated by the solvent casting method. The properties of films important for applicability were investigated, such as physical parameters, mucoadhesive force, surface free energy, and breaking strength. The fine structure of the films was analyzed by atomic force microscopy, and the free volume was analyzed by PALS, which can be important for drug release kinetics and the location of the drug in the film. The applicability of the optimized composition was also tested with two different types of active ingredients. The structure of the films was also analyzed by XRPD and FTIR. Ascorbic acid can be used well in chitosan films, where it can function as a permeation enhancer when reacting to chitosan, it is biodegradable, and can be applied in 2% of our studies.
RESUMEN
The design of mucoadhesive drug delivery systems (DDS) based on polysaccharides at nanoscale or microscale is a relevant technological strategy for the mucosal delivery of several drugs. Findings about the potential mucoadhesive ability of these materials and the mechanisms that drive such interactions represents an important advance for the rational modulation of these properties, according to specific uses. The potential mucoadhesive abilities of gellan gum (GG) and retrograded starch (RS) were investigated at pH 1.2 and 6.8, which were considered biorrelevant for the gastrointestinal tract (GIT). The effects of these polysaccharides on the MUC rheology were also addressed. Rheological studies revealed high MUC-GG interactions at both pH values (1.2 and 6.8), expressing a high mucoadhesive ability, mainly in acidic media. MUC-GG interactions were driven, mainly, by hydrogen bonds. At an acidic pH, significant changes occurred in the MUC arrangements due to the strong MUC-GG interactions, as corroborated by scanning electron microscopy (SEM). The rheological behavior of MUC-RS indicated poor interactions between them and MUC arrangements were more preserved as evidenced by SEM. The results of this work indicated that the mixing of GG and RS can be a promising strategy to modulate mucoadhesiveness of DDS, according to specific therapeutic needs.