Pharmaceutical delivery system

When new vaccines are developed, new pharmaceutical delivery systems and additives with properties suitable for this new class of vaccines must be developed. Promising additives and delivery systems have to be evaluated regarding their efficacy and toxicity. These vaccine formulations do not simply act as carriers but are also used to enhance the immune response against the administered antigen (as an... 

John Paproski, Pres., Pharmaceutical Delivery Systems... 

Metered dose inhalers (MDIs) are pharmaceutical delivery systems designed for oral or nasal use, which deliver discrete doses of aerosolized medicament to the respiratory tract. The MDI contains the active substance, dissolved or suspended in a liquefied propellant system held in a pressurized container that is sealed with a metering valve. Actuation of the valve discharges a metered dose of medicament as an aerosol spray through an actuator during oral or nasal inhalation. 

The advent of biotechnology, bioengineering and pharmaceutical delivery systems has increased the requirements for solubility and stability of macromolecules under a variety of versatile and unique conditions and subsequently the use of non-aqueous solvents. Specihc applications include a) isolation, purification, precipitation and crystallization of biopharmaceuticals, b) processing methods such as spray drying and microencapsulation, and c) formulation of proteins for delivery systems requiring high concentrations and prolonged stability, such as implants and depots. 

Due to the rapid advancement of new pharmaceutical delivery systems, this chapter covers only a limited number of techniques. Several of the techniques listed below may be necessary only at time zero or at release rather than being monitored at each stability time point. In addition, this chapter does not cover microbiological tests such as microbial limit, pyrogen, and sterility testing. 

Geary R, Schlameus H. Microparticulate pharmaceutical delivery system. US patent 5382435, 1995. Boedeker EC, Brown WR, Reid RH, Thies C, John EVH. Microparticle carriers of maximal uptake capacity by both M cells and non-M cells. US patent 5693343, 1997. 

Apart from these widely used products, other cellulosic ethers such as HPC, hydroxyethylcellulose and CMC are often used in the formulation of controlled pharmaceutical delivery systems. 

The polymer is covered by a composition of matter patent, US 4,066,747 issued on January 3, 1978 and assigned to the Alza Corporation. The use of acidic and basic excipients to control hydrolysis rate is covered by US Patents 5,030,457, issued in July 9, 1991 and is held by Pharmaceutical Delivery Systems and by US Patent 5,336,505, issued in August 9, 1994 also held by Pharmaceutical Delivery Systems. It is not commercially available, nor has had FDA approval. 

CONTROLLED RELEASE TECHNOLOGY - PHARMACEUTICAL] (Vol 7) PRUG DELIVERY SYSTEMS] (Vol 8) piGH TEMPERATURE ALLOYS] (Vol 13)... 

Since the development of the Spansule brand (Smith Kline Beech am) of coated beads and granules in the late 1960s, various dmg product technologies have been developed and patented to achieve extended durations of therapeutic effects. Each of these does so by various mechanisms of control of dmg release from adrninistered dosage forms. Each method has its advantages and disadvantages, a discussion of which is available in the pharmaceutical hterature (see Drug delivery systems) (21). 

Delivery systems that respond to changes in pH have been known to the pharmaceutical industry for more than a century. The pH-sensitive enteric coating is probably the oldest controUed-release technology. Unna introduced an enteric tablet coating based on keratin in 1884 (108). Enteric coatings are used primarily to protect the gastric mucosa from local irritation or to ensure that tablets do not dissolve until they reach the intestine. 

Xylans from beech wood, corncobs, and the alkaline steeping liquor of the viscose process have been shown to be applicable as pharmaceutical auxiliaries [3]. Micro- and nanoparticles were prepared by a coacervation method from xylan isolated from corncobs [150]. The process is based on neutralization of an alkaline solution in the presence of surfactant, which was shown to influence both the particle size and morphology. They are aimed at applications in drug delivery systems. 

Edwards-Levy, F., Andry, M. C. Levy, M. C. (1994). Determination of free amino group content of serum-albumin microcapsules. II. Effect of variations in reaction-time and terephthaloyl chloride concentration. International Journal of Pharmaceutics, Vol. 103, 3, (March 1994), pp. (253-257), ISSN 0378-5173 Friend, D. R. (2005). New oral delivery systems for treatment of inflammatory bowel disease. Advanced Drug Delivery Reviews, Vol. 57, 2, (January 2005), pp. (247-265), ISSN 0169-409X... 

Martin F. J. (1989). Pharmaceutical manufacturing of liposomes, in Specialized Drug Delivery Systems Manufacturing and Production Technology (P. Tyle, ed.), Marcel Dekker, New York. In Press. 

Yu LX, Lipka E, Crison JR and Amidon GL. Transport approaches to the bio-pharmaceutical design of oral drug delivery systems prediction of intestinal absorption. Adv Drug Deliv Rev 1996 19 359-76. 

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