Oral mucosa mucus

The function of the mucosal pellicle is to serve as a barrier between the oral epithelial surface and the external environment, and so it may also act as a barrier to drug delivery. However, there are limited studies assessing the role of the mucus layer in buccal permeability. In one study, treatment of the oral mucosa with anticholinergic agents resulted in an increased permeability of certain compounds, and it was suggested that the reduced salivary flow may have been responsible for the reduced barrier properties of the tissue [113]. In... 

Oral mucosae are covered with mucus which serves as a link between the adhesive and the membrane. Mucus is a glycoprotein consisting of a large peptide backbone with pendant oligosaccharide side chains. The side chains terminate in sialic or sulfonic acids, L-fucose, sulfated galactose, or A -acetylglucosamine. The glycoprotein component imparts the viscous or gel-like (non-Newtonian) nature due to its capacity... 

Oral mucosae are composed of multiple layers of cells, which show various patterns of differentiation dependent on the functions of different regions in the oral cavity. The oral mucosa is covered by a stratified, squamous epithelium, and three different types of mucosa can be distinguished the masticatory, the lining, and the specialized mucosa. Blood supply to the oral cavity tissues is delivered via the external carotid artery, which branches to the maxiliary lingual and facial artery. There are no mucus-secreting goblet cells in the oral mucosa, but mucins are found in human saliva. These mucins are water-soluble and form a gel of 10-200 pm thickness. Saliva, mainly composed of water (99%), is continuously secreted in the oral cavity and exists as a film with a thickness of 0.07-0.1 mm. ... 

Oral mucosae are covered with mucus that serves as a link between the adhesive and the membrane. Mucin is a polyelectrolyte under neutral or slightly acidic conditions because of the terminal sialic acid residues having a pA a value of 2.6. At physiological pH (7.4), the mucin molecule is polyanionic, which contributes to bioadhesion. 

Chronic snuff dipping has been associated with oral cancer in experimental animals and humans. Oral pharyngeal cancer accounts for 3% of these cancers and is the seventh most common form of cancer.The oral use of moist smokeless tobacco products (chewing tobacco) has increased in recent years, resulting in leukoplakia, which is a clinical white patch or plaque on the oral mucus membrane that cannot be removed by scrapping. Most of these lesions can occur in all areas of the oral cavity. Water-soluble smokeless tobacco extract has been shown to suppress lymphokine activated killer (LAK) cell activity by inhibiting DNA synthesis, and altered LAK function in the oral mucosa... 

The pertinent epithelia tissues of the oral cavity are the buccal and the sublingual ones. They are nonkeratinized tissues, both covered with a thin layer of mucus (Figure 1.8). The first is 500-800 pm thick, whereas the latter is 100-200 pm thick, and more vascularized than the former [121,122]. This difference in thickness may be a possible cause for the diversity in their permeabilities the sublingual is more permeable than the buccal mucosa, and the palatal mucosa is the least permeable. Permeability values of water and horseradish peroxidase (a 40-kDa heme protein commonly used as a permeation label) in the pig oral cavity are shown in Table 1.2. Blood vasculature in both epithelia of the oral cavity does not drain directly to... 

The type of patch allows release of the drug moiety to the underlying mucosa (and thus the systemic circulation) and also to the saliva bathing the oral cavity (Figure 7.3). Dmg released into the saliva may also be absorbed systemically through the mucus membranes of the oral cavity and/or remain locally. However, disadvantages associated with this approach include ... 

Upon intranasal administration, a drug is not as susceptible to dilution and first-pass effects as in oral delivery.46 47 The nasal route may also be an effective means of delivering drugs to the brain 46 Barriers to nasal delivery include the enzymes of the nasal mucosa, the epithelial barrier, the mucus layer, and limited absorption time resulting from mucociliary clearance.48... 

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