Oral administration drug delivery

Pan Y, Li YJ, Zhao HY, Zheng JM, Xu H, Wei G, Hao JS, Cui FD (2002) Bioadhesive polysaccharide in protein delivery system chitosan nanoparticles improve the intestinal absorption of insulin in vivo. Int J Pharm 249(1-2) 139-147 Park K, Robinson JR (1984) Bioadhesive polymers as platforms for oral-controlled drug delivery method to study bioadhesion. Int J Pharm 19 107-127 Patel H, Ryman BE (1981) Systemic and oral administration of liposomes. In Knight CG(ed) Liposomes From Physical Structure To Therapeutic Applications, Elsevier, Amsterdam, pp 409-441... 

Nitroglycerin (NTC) is distinguished by a high membrane penetrability and very low stability. It is the drug of choice in the treatment of angina pectoris attacks. For this purpose, it is administered as a spray, or in sublingual or buccal tablets for transmucosal delivery. The onset of action is between 1 and 3 minutes. Due to a nearly complete presystemic elimination, it is poorly suited for oral administration. Transdermal delivery (nitroglycerin patch) also avoids presystemic elimination. 

The transdermal route provides an alternative route to oral administration. Drugs delivered by this route avoid digestion in the gastrointestinal tract (GI), local metabolism related to the GI route, and hepatic first pass metabolism. It can provide controlled drug delivery with the possibility of zero order (continuous) release. Thus, it is most suitable for short half-life therapeutic agents and drugs with narrow therapeutic windows. The use of transdermal patches is more... 

Because of its convenience and good patient compliance, oral administration is the most preferred drug delivery form. As a result, much of the attention of in silico approaches is focused on modeling drug oral absorption, which mainly occurs in the human intestine. In general, drug bioavailability and... 

Historically, the oral route of administration has been used the most for both conventional and novel drug-delivery systems. There are many obvious reasons for this, not the least of which would include acceptance by the patient and ease of administration. The types of sustained- and controlled-release systems employed for oral administration include virtually every currently known theoretical mechanism for such application. This is because there is more flexibility in dosage design, since constraints, such as sterility and potential damage at the site of administration, axe minimized. Because of this, it is convenient to discuss the different types of dosage forms by using those developed for oral administration as initial examples. 

Sustained- and controlled-release devices for drug delivery in the vaginal and uterine areas are most often for the delivery of contraceptive steroid hormones. The advantages in administration by this route—prolonged release, minimal systemic side effects, and an increase in bioavailability—allow for less total drug than with an oral dose. First-pass metabolism that inactivates many steroid hormones can be avoided [183,184],... 

As pharmaceutical scientists gain experience and tackle the primary challenges of developing stable parenteral formulations of proteins, the horizons continue to expand and novel delivery systems and alternative routes of administration are being sought. The interest in protein drug delivery is reflected by the wealth of literature that covers this topic [150-154]. Typically, protein therapeutics are prepared as sterile products for parenteral administration, but in the past several years, there has been increased interest in pulmonary, oral, transdermal, and controlled-release injectable formulations and many advances have been made. Some of the more promising recent developments are summarized in this section. 

Most drugs are delivered at sites that are remote from their sites of action. Although the most convenient route of administration is the oral route, this presents significant challenges to the delivery of a drug molecule. Clearly, in order to be effective, an orally delivered drug must avoid several potential barriers. For example, it must ... 

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