Therapeutic surfactants

V(C) dependence has been studied for various surfactants such as NP20, 22-oxyethylated dodecyl alcohol, individual phospholipids and their natural mixture (amniotic fluid), lipoproteins, alveolar surfactants, therapeutic surfactants, etc. [e.g. 332,382,383-388]. For all of them this dependence is very steep. Such a course of the IV(C) curve is also... 

Toothpaste contains an abrasive (qv), flavor, a humectant system, a surfactant, a binding and thickening agent, color, and one or more therapeutic or cosmetic agents. 

The well-defined helical structure associated with appropriately substituted peptoid oligomers (Section 1.6) can be employed to fashion compounds that closely mimic the stracture and function of certain bioactive peptides. There are many examples of small helical peptides (<100 residues) whose mimicry by non-natural ohgomers could potentially yield valuable therapeutic and bioactive compounds. This section describes peptoids that have been rationaUy designed as mimics of antibacterial peptides, lung surfactant proteins, and coUagen proteins. Mimics of HIV-Tat protein, although relevant to this discussion, were described previously in this chapter (Sections 1.3.2 and 1.4.1). 

Lung surfactant is composed mainly of lipid with some proteins and carbohydrate and prevents the alveoli from collapsing. Surfactant activity is largely attributed to dipalmitoylphosphatidylcholine, which is synthesized shortly before parturition in full-term infants. Deficiency of lung surfactant in the lungs of many preterm newborns gives rise to respiratory distress syndrome. Administration of either natural or artificial surfactant has been of therapeutic benefit. 

Protein is an excellent natural nanomaterial for molecular machines. Protein-based molecular machines, often driven by an energy source such as ATP, are abundant in biology. Surfactant peptide molecules undergo self-assembly in solution to form a variety of supermolecular structures at the nanoscale such as micelles, vesicles, unilamellar membranes, and tubules (Maslov and Sneppen, 2002). These assemblies can be engineered to perform a broad spectrum of functions, including delivery systems for therapeutics and templates for nanoscale wires in the case of tubules, and to create and manipulate different structures from the same peptide for many different nanomaterials and nanoengineering applications. 

Therapeutic group Drug Surfactants/ excipients Propellant system Formulation type Particle size estimate (pm) References... 

Chemical PEs have recently been studied for increasing transdermal delivery of ASOs or other polar macromolecules [35]. Chemically induced transdermal penetration results from a transient reduction in the barrier properties of the stratum corneum. The reduction may be attributed to a variety of factors such as the opening of intercellular junctions due to hydration [36], solubilization of the stratum corneum [37, 38], or increased lipid bilayer fluidization [39, 40]. Combining various surfactants and co-solvents can be used to achieve skin penetration, purportedly resulting in therapeutically relevant concentrations of ASO in the viable epidermis and dermis [41]. In summary, it appears feasible to deliver ASO to the skin using a number of different delivery techniques and formulations. 

Modified and natural lipids and polymeric surfactants are increasingly being used in pharmaceutical formulations to increase the bioavailability of difficult drugs difficult usually because they have very poor solubility in aqueous environments. While these molecules may not themselves be biologically active, what happens to them in the gastrointestinal (GI) tract may influence their intended function, especially if they are acting to protect the active principle, for example, in the case of therapeutic peptides. 

Some biocidal surfactants, which are used as disinfectants or sterilants, come under the control of the TGA. These types of products are regulated as medical devices (Therapeutics Goods Order No, 54 (Standard for disinfectants and sterilants) (TG054) [15]. 

Amino acids are monomeric units of polypeptides and proteins. They are widely used in the food and chemical industries as flavor enhancers, seasonings and sweeteners e.g. for the improvement of bread quality, also in the production of drugs, cosmetics, synthetic leather and surfactants, in medicine for infusions and as therapeutic agents. Amino acids are produced by chemical synthesis or extraction from protein hydrolyzate. They may be also produced by microbiological methods. 

Pulmonary gene therapy is attractive for the treatmment of chronic bronchitis, cystic fibrosis, a-1 antitrypsin deficiency, familial emphysema, asthma, pulmonary infections, surfactant deficiency, pulmonary hypertension, lung cancer, and malignant mesothelioma. The pulmonary endothelium may act as a bioreactor for the production and secretion of therapeutic proteins, such as clotting factors and erythropoietin into the blood circulation. There is a potential benefit for acquired lung diseases, as well as cancers, to be controlled and possibly treated by expression of cytokines, surfactant, antioxidant enzymes, or mucoproteins within lung cells. 

Black Film Method for Assessment of Therapeutic Surfactants... 

EX, which is an incomplete surfactant and pa dependent for black film formation, may have a limited range of usefulness as a therapeutic agent. 

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