Concentrate processing delivery systems

A great number of researches have so far been carried on the incorporation of poly(IPAAm) and its copolymers in various biomedical devices, utilizing soluble/insoluble or swelling/deswelling processes in the temperature range of LCST. As overviewed by Okano et al. [44] these include drug delivery system (DDS) solute separation concentration of dilute solutions immobilization of enzymes detachment of cultured cells coupling to biomolecules, and other aspects. 

This volume term also depends on p and/or k10 and overestimates the volume. However, when terminal concentration-time data are used (i.e., distribution is at steady state and elimination is the process significantly altering Cp), this volume term will produce an accurate conversion factor between Cp and the amount of drug in the body. While Vda .a overestimates the volume, it can be useful in the design of controlled release delivery systems, particularly in pulsatile delivery. 

Achievement of a desired drug concentration-time profile. Although physiological processes govern the disposition of drug in the body, several pharmacokinetic parameters are still useful for evaluating drugs as candidates for controlled release delivery systems. In addition to potency, the pharmacokinetic parameters systemic clearance Cl, volume of... 

When the transdermal penetration of a drug is inadequate to achieve and maintain a plasma concentration above the minimum therapeutic concentration required to produce the desired effect, a lipophilic prodrug that will be metabolized in the epidermis to the active drug could be used in the development of a controlled-release transdermal delivery system. This approach has been applied to estradiol esters (diacetate and valerate) which are rapidly converted by esterases in the skin tissue to estradiol (Chien et al, 1985). The prodrug serves to increase the transdermal bioavailability of the active drug to which it is converted by metabolism (generally ester hydrolysis) during the percutaneous absorption process. 

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. 

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