Parenteral delivery

Table 11 Possible Problems Associated with Parenteral Delivery...

Parenteral administration is not perceived as a problem in the context of drugs which are administered infrequently, or as a once-off dose to a patient. However, in the case of products administered frequently/daily (e.g. insulin to diabetics), non-parenteral delivery routes would be preferred. Such routes would be more convenient, less invasive, less painful and generally would achieve better patient compliance. Alternative potential delivery routes include oral, nasal, transmucosal, transdermal or pulmonary routes. Although such routes have proven possible in the context of many drugs, routine administration of biopharmaceuticals by such means has proven to be technically challenging. Obstacles encountered include their high molecular mass, their susceptibility to enzymatic inactivation and their potential to aggregate. 

Pulmonary delivery currently represents the most promising alternative to parenteral delivery systems for biopharmaceuticals. Delivery via the pulmonary route moved from concept to reality in 2006 with the approval of Exubera, an inhalable insulin product (Chapter 11). Although the lung is not particularly permeable to solutes of low molecular mass (e.g. sucrose or urea), macromolecules can be absorbed into the blood via the lungs surprisingly well. In fact, pulmonary... 

J.E. Kipp, The role of solid nanoparticle technology in the parenteral delivery of poorly water-soluble drugs, Int. J. Pharm., 284, 109-122 (2004). 

The first modified CD to be explored significantly in parenteral delivery was the HP-P-CD. The development of this proprietary CD has been previously presented (8) and will be briefly summarized. 

Flurbiprofen Park and Kim (1999) Solubilization in emulsion formulation reduces volume required for parenteral delivery... 

Constantinides, P.P, Tustian, A., and Kessler, D.R. (2004)Tocol emulsion for drug solubilization and parenteral delivery.Adv. Drug Deliv. Rev., 56 1243-1255. 

Paborji, M., Riley, C.M., and Stella, V.J. (1988) A novel use of Intralipid for the parenteral delivery of perilla ketone (NSC-348407), an investigational cytotoxic drug with a high af nity for plhsttid. Pharm.,... 

Strickley, R.G. and Anderson, B.D. (1993) Solubilization and stabilization of an anti-HIV thiocarbamate, NSC 629243, for parenteral delivery, using extemporaneous emulSWnasm. Res., 10 1076-1082. 

For example, fosphenytoin is designed as a disodium salt ester prodrug of phenytoin (Fig. 3.9) to overcome parenteral delivery problems... 

Drug injection is a parenteral delivery method and bypasses problems associated with the first-pass effect and absorption through the digestive system. Delivery by injection is common despite several issues fear of needles, painful injections, and potential infection... 

The major liability of aptamers as drugs may reside in their need for parenteral delivery and the corresponding unwillingness of pharmaceutical... 

Parenteral delivery systems involve the use of needles. This is painful for the patient, as well as generally requiring the intervention of medical professionals. The oral route, which involves merely swallowing a tablet, liquid or capsule, thus represents a much more convenient and attractive route for drag delivery. Transdermal patches are also well accepted by patients and convenient. Some other dosage forms, for example nebulizers, pessaries and suppositories, may meet with more limited patient compliance. 

A commercial product based on conventional liposomes has been introduced for the parenteral delivery of the anti-fungal drug, amphotericin B, which is poorly tolerated in conventional formulations. AmBisome, a liposomal formulation of amphotericin B, comprises SUV of diameter 50-100 ran. Two other lipid-based formulations of amphotericin B have also recently been commercially introduced ... 

Niosomes have been developed as an alternative to phospholipid-based liposomes. They are based on several different families of synthetic, non-ionic ampliipatic molecules. At present, there is rather limited experience with niosomes as a parenteral delivery system and no clear advantages over liposomal systems have been established yet. 

Treatment of pernicious anaemia has traditionally involved the parenteral delivery of vitamin B12 to ensure absorption. Oral replacement is now an accepted route, using large doses of vitamin B12, 1-2mg daily. 

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