Naturally derived active ingredients

The use of topical repellents applied to exposed skin is the most important personal intervention against vectors of diseases, and numerous studies have been undertaken to enumerate the protection against biting vectors, especially mosquitoes. The use of repellent active ingredients such as A,A-diethyl-3-methylbenzamide (deet), 2-(2-hydroxyethyl)-l-piperidinecarboxylic acid 1-methylpropyl ester (icaridin, picaridin), lemon eucalyptus oil (p-menthane-3,8-diol) and ethyl butylacetylaminopropionate (IR3535), as well as several infrequently used synthetic and naturally derived active ingredients are discussed in detail in Chapter 19. 

Figure 7 shows the course of development of various synthetic pyrethroids developed by retaining chrysanthemic acid as the acid moiety and modifying the alcohol moiety. Numerous useful compounds with favorable characteristics have been derived from the structural modification of natural cinerin I (7). These underlined compounds have been put into practical use as active ingredients, mainly for household insecticides. 

The case stndy of the SP development of an HPLC assay method for an OTC prodnct derived from natural materials illustrates the importance of optimizing both the extraction and filtration conditions to fully recover all the labile active components in the formulation. The HPLC gradient assay method, which separates all active ingredients from other... 

Preservatives In addition to those processing controls mentioned above (Section 3.1.4.3), the sterility of a product may be maintained through the addition of antimicrobial preservatives. Preservation against microbial growth is an important aspect of multidose parenteral preparations as well as other formulations that require preservatives to minimize the risk of patient infection upon administration, such as infusion products [52], Aqueous liquid products are prone to microbial contamination because water in combination with excipients derived from natural sources (e.g., polypeptides, carbohydrates) and proteinaceous active ingredients may serve as excellent media for the growth [57], The major criteria for the selection of an appropriate preservative include efficiency against a wide spectrum of micro-... 

Quinolines represent an important class of heterocycles, and the quinoline skeleton is present in various natural products, especially in alkaloids. Among them quinine is an active ingredient for the treatment of malaria [286]. Despite its relatively low efficacy and tolerability, quinine still plays an important role in the treatment of multiresistant malaria, one of the world s most devastating infectious diseases [287]. Therefore, the design of many drugs and affordable chemotherapies are based upon synthetic quinoline derivatives, such as chloroquine, mefloquine or quinacrine [288-292]. In addition, chimanine alkaloids, are also effective against parasitic diseases such as leishmaniasis and trypanosomiasis [293-295]. Besides,... 

Pure polyunsaturated fatty acid amides and their derivatives. These synthcally produced compounds are able to mimic naturally occuring anandamides in the brain and bind the cannabinoid receptor. The compounds exhibit physiological activity and are useful as active ingredients in pharmaceutical compositions for the treatment of inflammation, migraines, spasticity activity, glaucoma, multiple sclerosis. 

Oral contraceptives for women contain as active ingredients progestogens and oestrogens. These substances are semisynthetic derivatives, which are based on naturally occurring steroids. 

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