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The Route And Process Of Ocular Administration
The eye is a special sensory organ of the human body and an important part of the body. Ocular lesions are closely related to and interact with other tissue system lesions throughout the body. The special structure and physiological characteristics of the eye make ophthalmic drugs have their own characteristics in the way and route of administration. Most drugs enter the aqueous humor through the cornea, and then are distributed in surrounding tissues, such as the ciliary body, lens, vitreous body, choroid, retina, and a small amount of drugs enter the pigment membrane and vitreous body through the conjunctiva and sclera . There is a barrier between the tissue fluid…
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Overview and Characteristics Of Ophthalmic Nano Drug Delivery System
Most ophthalmic drugs are administered locally in the conjunctival sac, and the most commonly used dosage form is eye drops. Due to various physiological barriers, the eye bioavailability of eye drops is extremely low, generally less than 5%. On the one hand, the main reason is the rapid elimination rate of the drug on the ocular surface and short residence time. Most of the drugs instilled in the eye are lost quickly with the tears (partly absorbed by the conjunctiva and nasal mucosa into the systemic circulation), and partly bound by the contents of the tears or Decomposition; On the other hand, the absorption of the corneal route and the…
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A Few Tips To Better Know About Neutral Lipids
What Are Neutral Lipids? Neutral lipids are defined as hydrophobic molecules lacking charged groups. Neutral lipids, such as cholesteryl ester (CE), triacylglycerol (TAG), and wax ester (WE), provide organisms with inert forms of energy used in conditions of nutrient deprivation and environmental stress. They also provide an excellent “sink” to buffer the toxic effects of fatty acids and fatty alcohols. Elevated cytoplasmic deposition of neutral lipids (primarily CE and TAG) is a significant risk factor for several disease pathologies, including diabetes, obesity, atherosclerosis, and nonalcoholic fatty liver disease (41, 53, 101). For example, the accumulation of CE in smooth muscle cells and macrophages in the vessel wall comprises the earliest recognizable stage…
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What Are Sphingolipids?
Sphingolipids are the most structurally diverse class of membrane lipids, being composed of over 70 long-chain (sphingoid) bases, dozens of amide-linked fatty acids, and more than 300 headgroups. Sphingolipids are present in all eukaryotic and some prokaryotic organisms. 1.What Is The Function Of A Sphingolipid? Sphingolipids are highly bioactive compounds that participate in the regulation of cell growth, differentiation, diverse cell functions, and apoptosis. Sphingolipids are both structural and functional lipids. Their physical properties (such as high phase transition temperatures) affect the properties of membranes and lipoproteins, and they are critical components of the water barrier of skin. Besides, they serve as ligands for extracellular matrix proteins and receptors on…
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Protein Peptide Drug Lung Inhalation Nano Preparation
Pulmonary administration has great advantages as a non-invasive route of administration of protein and peptide drugs. The human respiratory tract has a large surface area, which can avoid the first pass effect of the liver. In addition, the viscosity of the epithelial cell barrier is low, and there is a large amount of potential vasculature, low proteolytic activity and low acidity. Compared with the gastrointestinal tract, there is a thinner mucus layer, so the lungs are suitable for local and systemic administration. However, the mucosa of the respiratory tract is very tight and complex, and it is difficult for macromolecular drugs to penetrate. In fact, a single macromolecule is difficult…
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What Are Monomers?
Monomers are molecules that can react together with other monomer molecules to form a larger polymer chain or three-dimensional network in a process called polymerization. There are mainly four types of monomers, including sugars, amino acids, fatty acids, and nucleotides, and each of these monomer types plays an important role in the existence and development of life, and each can be synthesized through abiotic means. What Are Monomers Made? Polymers are synthetic substances that consist of multiple simpler units called monomers. A polymer is a chain with an indefinite number of monomer units. Homopolymers are polymers made by joining together monomers with the same chemical composition or structure. How Do You Identify Monomer?…
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What Are Block Copolymer Micelles?
Block copolymer micelles are generally formed by the self-assembly of either amphiphilic or oppositely charged copolymers in aqueous medium. The hydrophilic and hydrophobic blocks form the corona and the core of the micelles, respectively. Block copolymer micelles can be classified according to the type of intermolecular forces driving the segregation of the core segment from the aqueous milieu. In the past few decades, at least three main categories were identified, viz. amphiphilic micelles (formed by hydrophobic interactions), polyion complex micelles (PICM; resulting from electrostatic interactions), and micelles stemming from metal complexation. Generally, when the hydrophilic segment is longer than the core block, the shape of the resulting micelles is spherical. Conversely, increasing…
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Lung Inhalation Nano Drug Delivery System Dosage Form
The existing pulmonary inhalation nano drug delivery system dosage forms are mainly divided into two types: liposomes and nanoparticles. Liposomes Among the various dosage forms for pulmonary administration, liposomes have obvious advantages, such as being suitable for encapsulating lipophilic drugs, avoiding local irritation, enhancing curative effects, reducing toxic and side effects, and evenly distributing active drugs in the lungs. Lung-administered liposomes can also be used for gene therapy. Compared with viral vectors, liposomes are simple to prepare, have no damage to normal tissues, and have high safety. Liposome pulmonary drug delivery has the following characteristics: 1. The main component of alveoli is lipids, among which phospholipids account for 80% of…
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What Are Natural Phospholipids?
Lipids are defined as apolar molecules comprising as major classes fatty acids and fatty acid esters of normally natural origin. Non-natural components, such as dicarba-closo-dodecaboranes (in short carboranes) can also form acids and esters, which reveal lipid-like properties. Phospholipids are lipids usually composed of three components: a diglyceride, a phosphate group and another organic molecule such as choline, to produce phosphatidylcholine. Phospholipids are a major component of all cellular membranes and can form bilayers. What Are Examples of Phospholipids? The most common phospholipids are phosphatidylcholine, phosphatidylethanolamine, phosphatidylinositol, and phosphatidylserine. These phospholipids share the common features of fatty acids esterified to the 1 and 2 positions of the glycerol backbone with the phosphate…
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What Are PEGs?
PEGs (polyethylene glycols) are composed of polyether compounds repeating ethylene glycol units according to the constituent monomer or parent molecule (as ethylene glycol, ethylene oxide, or oxyethylene) (Fig. 1). Most PEGs are commonly available commercially as mixtures of different oligomer sizes in molecular weight (MW) ranges. For instance, PEG-10,000 typically designates a mixture of PEG molecules (n = 195 to 265) having an average MW of 10,000. PEG is also known as polyethylene oxide (PEO) or polyoxyethylene (POE), with the three names being chemical synonyms. However, PEGs mainly refer to oligomers and polymers with molecular masses below 20,000 g/mol, while PEOs are polymers with molecular masses above 20,000 g/mol, and POEs are…
