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Hydrophilization is a process used on hydrophobic drugs to increase their release rate from capsules, which depends on the rate of dissolution, by covering the surfaces of their particles with minute droplets of a dissolved hydrophilic polymer (such as methyl cellulose or hydroxyethyl cellulose). [1] [2] In tablet or capsule formulations, this enhances the dissolution and disintegration of the drug. [2]
A micelle or micella is an aggregate of surfactant amphipathic lipid molecules dispersed in a liquid, forming a colloidal suspension. A typical micelle in water forms an aggregate with the hydrophilic "head" regions in contact with surrounding solvent, sequestering the hydrophobic single-tail regions in the micelle centre.
An excipient is a substance formulated alongside the active ingredient of a medication. They may be used to enhance the active ingredient’s therapeutic properties; to facilitate drug absorption; to reduce viscosity; to enhance solubility; to improve long-term stabilization ; or to add bulk to solid formulations that have small amounts of potent active ingredients. During the manufacturing process, excipients can improve the handling of active substances and facilitate powder flow. The choice of excipients depends on factors such as the intended route of administration, the dosage form, and compatibility with the active ingredient.
Microencapsulation is a process in which tiny particles or droplets are surrounded by a coating to give small capsules, with useful properties. In general, it is used to incorporate food ingredients, enzymes, cells or other materials on a micro metric scale. Microencapsulation can also be used to enclose solids, liquids, or gases inside a micrometric wall made of hard or soft soluble film, in order to reduce dosing frequency and prevent the degradation of pharmaceuticals.
In biotechnology, polymersomes are a class of artificial vesicles, tiny hollow spheres that enclose a solution. Polymersomes are made using amphiphilic synthetic block copolymers to form the vesicle membrane, and have radii ranging from 50 nm to 5 μm or more. Most reported polymersomes contain an aqueous solution in their core and are useful for encapsulating and protecting sensitive molecules, such as drugs, enzymes, other proteins and peptides, and DNA and RNA fragments. The polymersome membrane provides a physical barrier that isolates the encapsulated material from external materials, such as those found in biological systems.
Natural fibers or natural fibres are fibers that are produced by geological processes, or from the bodies of plants or animals. They can be used as a component of composite materials, where the orientation of fibers impacts the properties. Natural fibers can also be matted into sheets to make paper or felt.
An enteric coating is a polymer barrier applied to oral medication that prevents its dissolution or disintegration in the gastric environment. This helps by either protecting drugs from the acidity of the stomach, the stomach from the detrimental effects of the drug, or to release the drug after the stomach. Some drugs are unstable at the pH of gastric acid and need to be protected from degradation. Enteric coating is also an effective method to obtain drug targeting. Other drugs such as some anthelmintics may need to reach a high concentration in a specific part of the intestine. Enteric coating may also be used during studies as a research tool to determine drug absorption. Enteric-coated medications pertain to the "delayed action" dosage form category. Tablets, mini-tablets, pellets and granules are the most common enteric-coated dosage forms.
Methyl cellulose is a compound derived from cellulose. It is sold under a variety of trade names and is used as a thickener and emulsifier in various food and cosmetic products, and also as a bulk-forming laxative. Like cellulose, it is not digestible, non-toxic, and not an allergen. In addition to culinary uses, it is used in arts and crafts such as papier-mâché and is often the main ingredient of wallpaper paste.
Absorption is the journey of a drug travelling from the site of administration to the site of action.
Poloxamers are nonionic triblock copolymers composed of a central hydrophobic chain of polyoxypropylene flanked by two hydrophilic chains of polyoxyethylene. The word poloxamer was coined by BASF inventor, Irving Schmolka, who received the patent for these materials in 1973. Poloxamers are also known by the trade names Pluronic, Kolliphor, and Synperonic.
Cellulose acetate phthalate (CAP), also known as cellacefate (INN) and cellulosi acetas phthalas, is a commonly used polymer phthalate in the formulation of pharmaceuticals, such as the enteric coating of tablets or capsules and for controlled release formulations. It is a cellulose polymer where about half of the hydroxyls are esterified with acetyls, a quarter are esterified with one or two carboxyls of a phthalic acid, and the remainder are unchanged. It is a hygroscopic white to off-white free-flowing powder, granules, or flakes. It is tasteless and odorless, though may have a weak odor of acetic acid. Its main use in pharmaceutics is with enteric formulations. It can be used together with other coating agents, e.g. ethyl cellulose. Cellulose acetate phthalate is commonly plasticized with diethyl phthalate, a hydrophobic compound, or triethyl citrate, a hydrophilic compound; other compatible plasticizers are various phthalates, triacetin, dibutyl tartrate, glycerol, propylene glycol, tripropionin, triacetin citrate, acetylated monoglycerides, etc.
Modified-release dosage is a mechanism that delivers a drug with a delay after its administration or for a prolonged period of time or to a specific target in the body.
Thin-film drug delivery uses a dissolving film or oral drug strip to administer drugs via absorption in the mouth and/or via the small intestines (enterically). A film is prepared using hydrophilic polymers that rapidly dissolves on the tongue or buccal cavity, delivering the drug to the systemic circulation via dissolution when contact with liquid is made.
Hydroxyethyl cellulose is a gelling and thickening agent derived from cellulose. It is widely used in cosmetics, cleaning solutions, and other household products. Hydroxyethyl cellulose and methyl cellulose are frequently used with hydrophobic drugs in capsule formulations, to improve the drugs' dissolution in the gastrointestinal fluids. This process is known as hydrophilization.
Polymers with the ability to kill or inhibit the growth of microorganisms such as bacteria, fungi, or viruses are classified as antimicrobial agents. This class of polymers consists of natural polymers with inherent antimicrobial activity and polymers modified to exhibit antimicrobial activity. Polymers are generally nonvolatile, chemically stable, and can be chemically and physically modified to display desired characteristics and antimicrobial activity. Antimicrobial polymers are a prime candidate for use in the food industry to prevent bacterial contamination and in water sanitation to inhibit the growth of microorganisms in drinking water.
Peptide amphiphiles (PAs) are peptide-based molecules that self-assemble into supramolecular nanostructures including; spherical micelles, twisted ribbons, and high-aspect-ratio nanofibers. A peptide amphiphile typically comprises a hydrophilic peptide sequence attached to a lipid tail, i.e. a hydrophobic alkyl chain with 10 to 16 carbons. Therefore, they can be considered a type of lipopeptide. A special type of PA, is constituted by alternating charged and neutral residues, in a repeated pattern, such as RADA16-I. The PAs were developed in the 1990s and the early 2000s and could be used in various medical areas including: nanocarriers, nanodrugs, and imaging agents. However, perhaps their main potential is in regenerative medicine to culture and deliver cells and growth factors.
A hydrophile is a molecule or other molecular entity that is attracted to water molecules and tends to be dissolved by water.
Cellulose diacetate, sometimes called diacetate, is a synthetic polymer made by treating cellulose with acetic acid. It consists of two acetyl functional groups on each unit of D-anhydroglucopyranose of the cellulose molecule. It was first developed in the United States.
A nanocarrier is nanomaterial being used as a transport module for another substance, such as a drug. Commonly used nanocarriers include micelles, polymers, carbon-based materials, liposomes and other substances. Nanocarriers are currently being studied for their use in drug delivery and their unique characteristics demonstrate potential use in chemotherapy. This class of materials was first reported by a team of researchers of University of Évora, Alentejo in early 1960's, and grew exponentially in relevance since then.
Buccal administration is a topical route of administration by which drugs held or applied in the buccal area diffuse through the oral mucosa and enter directly into the bloodstream. Buccal administration may provide better bioavailability of some drugs and a more rapid onset of action compared to oral administration because the medication does not pass through the digestive system and thereby avoids first pass metabolism. Drug forms for buccal administration include tablets and thin films.
Bovine submaxillary mucin (BSM) coatings are a surface treatment provided to biomaterials intended to reduce the growth of disadvantageous bacteria and fungi such as S. epidermidis, E. coli, and Candida albicans. BSM is a substance extracted from the fresh salivary glands of cows. It exhibits unique physical properties, such as high molecular weight and amphiphilicity, that allow it to be used for many biomedical applications.