Advantages as drug carriers

Micelles as drug carriers provide many advantages. Comparing with cosolvent formulation, micellar formulation has less tendency of precipitation on dilution. They physically entrap sparingly... 

Emulsions have been used for centuries for the oral administration of medical oils and vitamins and as dermatological vehicles. Recently, their application has been extended as drug carriers in the delivery and targeting of ophthalmic drags. An indomethacin emulsion has been reported to increase ocular bioavailability and efficacy compared to commercially available formulation in rabbits. 0.4% indomethacin emulsion showed 2.2 fold increase in the area under the anterior aqueous drag concentration/time curve compared to a 1% indomethacin suspension. The emulsion formulation also reduced ocular surface irritation caused by indomethacin Similar advantages have been shown for a pilocarpine emulsion which produced a prolonged therapeutic effect in comparison with pilocarpine hydrochloride eyedrops in man. It can be administered only twice a day, rather than four times daily for conventional formulation. 

NMR spectroscopy represents a valuable and versatile tool for the characterization of dispersed nanoparticles. In contrast to alternative analytical techniques, it combines a distinctly non-invasive character with the ability to analyse for chemical composition as well as for local mobility of individual system components. Its main disadvantages - poor sensitivity and time consuming acquisition of experimental data - can be overcome by a suitable choice of the pulse sequence and the experimental conditions. The advantages of the NMR approach are especially promising for the study of nanoparticle dispersions used as drug carriers, where many important system characteristics such as release properties, surface exchange processes or decomposition pathways are readily available by relatively simple pulse experiments. 

Dendrimer-based drug delivery systems have been successful in both improving bioavailability as well as targeting drugs. The main advantages for the use of dendrimers as drug carriers reside in their multivalent design and their well-defined structure that results from the stepwise, iterative approach used in their preparation. The anionic and neutral dendrimers have been shown to be less toxic than the cationic dendrimers but at the same time they suffer from lower permeability compared to cationic dendrimers. Typically the smaller size of dendrimers... 

Various methods to prepare polymeric hydrogels for novel CL-based ophthalmic drug delivery systems are critically analyzed in Section 51.4.8. In addition, advantages and limitations of CLs as drug carriers and then a more extensive analysis of the approaches made to modify the polymeric networks at the nanoscale in order to improve drug loading and release performance will be discussed. 

Synthetic polymers are advantageously used as drug carriers since they are clearly more susceptible to modifications than natural macromolecules. Natural polymers usually have a limited number of functional groups suitable for binding a drug... 

The use of natural macromolecules as drug carriers possesses several advantages and also disadvantages. Their production is inexpensive, even on large scale they are biodegradable and often well tolerated by the organism and, in most cases, their macromolecules are uniform and well defined. On the other hand, the batch-to-batch reproducibility is rather low, they may lose biodegradability after chemical modification, their... 

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