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Conducting Polymers for Ophthalmic Applications
Published in Ram K. Gupta, Conducting Polymers, 2022
The mucoadhesion process can be summarized in three steps. In the first step, the biopolymer gets wet, then swells after it settles on the mucosal membrane. This process is governed by the wetting theory. The second step involves the interpenetration of polymer chains with the mucosal surface by forming physical bonds. This process is governed by a combination of adsorption and electronic theories. In the third and final step, the adhesion is reinforced by the covalent bonding of the polymer chains. This process is governed by a combination of electronic theory, adsorption theory, and diffusion theory. Most of biopolymers are known for their ability to adhere to tissues and have an ionized to known as a polyelectrolyte (PE). PEs are a subclass of polymers that have different properties from other polymers thanks to their ionic structure. PEs are beneficial in biomedical applications because of their ability to bind to oppositely charged surfaces or form complexes with oppositely charged polymers. Many natural PEs rely on electrostatic interactions with charged subcellular membranes or lipid bilayers of cellular to function biologically [21]. Some of the most widely known mucoadhesive polymers can be listed as chitosan (CS), alginate (ALG), carbomer, methylcellulose (MC), and hyaluronic acid (HA) [20].
Recent Advances in Pharmaceutical Applications of Natural Carbohydrate Polymer Gum Tragacanth
Published in Amit Kumar Nayak, Md Saquib Hasnain, Dilipkumar Pal, Natural Polymers for Pharmaceutical Applications, 2019
Madhusmita Dhupal, Mukesh Kumar Gupta, Dipti Ranjan Tripathy, Mohit Kumar, Dong Kee Yi, Sitansu Sekhar Nanda, Devasish Chowdhury
Mucoadhesive are bioactive drug delivery pharmaceutics (tablet, patch, emulsion), which adheres to the mucosal surface of the gastrointestinal tract (GIT), oral cavity, nasal cavity, vaginal cavity and mucosae surrounding the eyes for sustained release of the dosage via mucosal epithelia, cilia. Over the past few decades, GT-based mucosal drug delivery has received great attention for prolonged, controlled drug release improving therapeutic outcome. Recently, Jabri et al., (2018) used GT composed gold (AuNPs) nanoparticle for loading Amphotericin B (AmpB) through the solvent diffusion method and investigated for enhanced oral bioavailability in a rabbit model. Results revealed that GT-Au-AmpB hybrid NPs enhanced AmpB oral bioavailability in a sustained and controlled manner (Jabri et al., 2018).
Nanostructures for Improving the Oral Bioavailability of Herbal Medicines
Published in Bhaskar Mazumder, Subhabrata Ray, Paulami Pal, Yashwant Pathak, Nanotechnology, 2019
Since most of the orally administered particles are not retained and undergo direct transit through the GI tract, mucoadhesive formulations have often been employed to improve the residence time of the particles in the GI tract (Ensign et al., 2012). Mucoadhesive formulations provide a prolonged and intimate contact of the dosage form with biological surfaces, leading to better absorption and bioavailability. A polycaprolactone-based nanoparticle loaded with curcumin was coated with mucoadhesive polymers of chitosan for buccal delivery (Mazzarino et al., 2012). Uniform particle size ranging between 114 and 125 nm was obtained and the encapsulation efficiency was remarkably high at 99%. The chitosan-coated nanoparticles exhibited a positive charge, showing their capacity to provide adhesion to the negatively-charged mucosal surface. A superior anticancer effect in a colorectal cancer model was also reported for the mucoadhesive, curcumin-containing chitosan nanoparticles (Chuah et al., 2014). An ex vivo study on an everted SD rat intestinal sac model was performed, which showed that curcumin-containing chitosan nanoparticles resulted in improved mucoadhesion and were also taken up to a greater extent by colorectal cancer cells when compared to free curcumin. The prolonged contact resulting from the mucoadhesion of curcumin-containing chitosan nanoparticles onto the cells leads to a greater reduction in percentage cell viability and a lower IC50, which indicates its potential for an improved treatment outcome.
Design and optimization of liquisolid compact based vaginal sustained release tablet of antifungal agent for vaginal candidiasis
Published in Journal of Dispersion Science and Technology, 2022
Pranita S. Kanojiya, Pradip N. Ghodake, Rita N. Wadetwar
The setup of the mucoadhesion study is shown in Figure S3. The mucoadhesive drug delivery system increases the time of residence at the desired site and offer close contact between the dosage form and tissue of interest that will absorb the drug. This may result in higher drug level in the local area that would result in high flux of drug through the tissue. This could impact on the bioavailability and improve the drug permeation that is related to the time of contact with the mucosal tissue. The hydrophilic matrix based drug delivery system could be formulated to impart the mucoadhesion to the desired tissue that is achieved on the wetting of the polymer with the biological fluid. HPMC K4M was chosen due to the good mucoadhesion property. It is nonionic polymer and therefore the mucoadhesion does not depend on the pH of the surrounding biological fluid. Hence this favors the mucoadhesion at any of the body pH including the vaginal pH. The mucoadhesive strength for the tablet formulation ranged from 1963.6 to 2546 dyne/cm2. Therefore the tablet was adhered properly to the goat vaginal tissue due to the HPMC K4M polymer. The polymer bears various hydroxyl groups that account for the adhesive property. Due to the polymer swelling there is higher surface available for the exposure with the mucosal tissue. This in turn causes increased hydrogen bonding between the mucosal tissue and the polymer and therefore mucoadhesive strength of the polymer increases.[33]
Plant gums for sustainable and eco-friendly synthesis of nanoparticles: recent advances
Published in Inorganic and Nano-Metal Chemistry, 2020
Multiple-unit mucoadhesive carriers combine the abilities of the mucoadhesive dosage forms with the advantageous properties of the multiparticulate drug delivery systems (e.g., uniform dispersion in the targeting site, more reproducible drug absorption and reduced local irritation).[34,35] This technique was applied for improvement of buccal delivery of vitamin B6, a highly water-soluble, low permeable vitamin.[36] Different gums, as mucoadhesive compounds, could be used for delivery of lipid vesicular carriers for oral,[37,38] ocular,[39–41] nose to brain,[42] and vaginal[43] drug delivery. Chitosomes, i.e., liposomes coated by a polyelectrolyte complex between chitosan and xantan gum, has potential delivery system for oral administration of poorly absorbable drugs.[44] This polyelectrolyte complex could improve stability and mucoadhesive property of lipid bilayers[16] Xanthan and guar gums have been applied as thickeners for improving β-carotene liposome stability used as a lipophilic antioxidant.[38] Guar gum and cationic guar gum were used to improve amphiphile bilayer membrane stability and reduce degradation of encapsulated curcumin.[45]
Study of physicochemical properties of flutamide-loaded Ocimum basilicum microspheres with ex vivo mucoadhesion and in vitro drug release
Published in Particulate Science and Technology, 2018
Pradum Pundlikrao Ige, Rohit Ravindra Badgujar, Pankaj Padmakar Nerkar, Hitendra Shaligram Mahajan, Raju Onkar Sonawane, Sanjay Javarilal Surana
The particle size is a crucial factor because it determines the rate and extent of drug release as well as drug absorption. The smaller particle size provides a larger interfacial surface area for drug absorption. Particle size values of microspheres were found to be in between 2.53 and 11.92 µm (Table 1 and Figure 5). It was found that the polymer to drug ratio of microspheres had significant effect on the particle size of microspheres. Increase feed flow rate also contributed to the increased particle size but not much significantly. This might be due to the narrower range being selected to focus this parameter. The OBM microspheres prepared were negatively charged, indicating the presence of OBM at the surface of all batches flutamide-loaded microspheres. It has reported that poly anion polymers are more effective mucoadhesive than poly cation or nonionic polymers.