Comparison of the mucoadhesive properties of varios polymers. Contact time between mucoadhesive and mucus layer determines the extent of chain interpenetration. However, it is of value when the bioadhesive system is formulated as a patch. Duchene[ 11 ] adapted Equation 5 to give Equation 6 , which can be used to determine the time, t , to bioadhesion of a particular polymer:. The peel test is based on the calculation of energy required to detach the patch from the substrate. Bioadhesion, new possibilities for drug administration? Buccal administration of human insulin in streptozocin-diabetic rats.
Development and evaluation of acid-buffering bioadhesive vaginal Tablet for Mixed vaginal Infections. This strategy can be useful for instance, in drugs targeting tumor tissues Chowdary, Rao, Many bioadhesives used in drug delivery are polyanions possessing carboxylic acid functionalities. Therefore, a bioadhesive system controlling drug release could improve the treatment of diseases, helping to maintain an effective concentration of the drug at the action site Huang et al. Shermer[ 84 ] evaluated the efficacy and tolerability of a mucoadhesive patch compared with a pain-relieving oral solution for the treatment of aphthous stomatitis.
The existence of concentration gradients will drive the polymer chains of the bioadhesive into the mucus network and the glycoprotein mucin chains into the bioadhesive matrix until an equilibrium penetration depth is achieved as shown in Figure 2. The mucous membrane to be analyzed can be attained after an experiment using an everted gut sac Mathiowitz, Chickering, Lehr, Falling Liquid Film Method Nielsen, Schubert and Hansen used a method proposed by Rango Rao and Buri in which the chosen mucous membrane is placed in a stainless steel cylindrical tube, which has been longitudinally cut.
In this case, the equation should be expanded to accommodate elastic dimensions and modules for each component.
Mucoadhesive drug delivery systems
Influence of mucin type on polymer-mucin rheological interactions. Preparation and characterisation of ph- sensitive, interpenetrating networks of poly vinyl alcohol and poly acrylic acid J Appl Polym Sci. On a log-log graph, they are represented by a constant straight line.
The conjunctiva contains around 1. Despite the relatively hydrophilic nature of 5-fluorouracil, substantial drug release through human cervical tissue samples was observed over approximately 20 h. No technology has still been developed specifically to analyze mucoadhesion. Moisture-activated, electrically-conducting bioadhesive hydrogels as interfaces for bio-electrodes: Table 3 Different types of mucoadhesive dosage forms.
Diffusion Theory of Mucoadhesion Diffusion theory describes that polymeric chains from the bioadhesive interpenetrate into glycoprotein mucin chains and reach a sufficient depth within the opposite matrix to allow formation of a semipermanent bond. For less organized systems, dynamic moduli are dependent on the frequency and a slope is observed.
Fracture energy g c can be obtained from the reversible adhesion work, W r energy required to produce new fractured surfacesand the irreversible adhesion work, W i work of plastic deformation provoked by the removal of a proof tip until the disruption of the adhesive bondand both values are expressed as units of fracture surface A f.
Pharmaceutical and medical aspects of bioadhesive systems for drug administration. Biorelated Polymers and Gels.
Ocular Mucoadhesive Drug Delivery Systems Drug administration to the eye is a challenge because there are several mechanisms tear production, tear flow, and blinking that protect the eye from the harmful agents. Bioadhesion of Hydrated Chitosans: This tip moves toward a plane parallel to the sample, acquiring its topographic characteristics and the tip position is recorded by an optic deflection system: Other physiological variations can also occur with diseases Lee, Park, Robinson, Surface area without villi gives it a relatively small surface area for drug absorption.
This work, which causes the rearrangements of the macromolecules, is the basis of the change in viscosity.
Thus mucosal drug delivery system could be of value in delivering a growing number of high-molecular-weight sensitive molecules such as peptide and oligonucleotides. Epithelium consists of a single layer of cylindrical cells and goblet cells secreting mucus. Functionalized mucoadhesive polymers, such as polycarbophil, hyaluronan, and amberlite resin, have been developed and the characterization and safety aspects of nasal drug products extensively studied.
The zeta potential of dispersion syshem defined as the potential between the liquid superficial layer surrounding the dispersed particle and the remaining solution volume. However, it has been demonstrated that the rupture rarely occurs at the surface, but near it Mathiowitz Chickering; Lehr, or at the weakest point, which can be the interface itself, the mucus layer or the hydrated region of the mucus, as illustrated in Figure 5 Smart, Oral Mucoadhesive Drug Delivery Systems Drug delivery through the oral mucosa has gained significant attention deivery to its convenient accessibility.
Kamath KR, Park K. Due to their high specificity, antibodies can be a rational deilvery as polymeric ligand in the development of site-specific mucoadhesives. Various theories exist to explain at least some of the experimental observations made during the bioadhesion process. The authors concluded that thiamine-coated nanoparticles showed promise as particulate vectors for oral vaccination and immunotherapy.
Mucoadhesive drug delivery systems
When a mucin particle binds to the polymer at the sensor, both the solute concentration and the refraction index on this surface undergo changes, where the interaction is quantitatively evaluated and reproduced on a diagram. Bioadhesive Controlled Release Systems. Super-hydration of the system can lead to build up of mucilage without adhesion.
Lined with mucous membrane containing columnar cells, goblet cells, and basal cells.