Sustainable design administrative sustainability

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. 

Figure 4 Mean it-verapamil S-verapamil ratio observed following intravenous and oral dosing of racemic verapamil. A, After intravenous administration of a single 15 mg dose in 8 volunteers (personal communication from A. Rasymas, Univ. of Toronto, Canada). B, After oral administration of two different 120-mg immediate release formulations dosed every 8 hr to 22 normal volunteers in a crossover design study and measured at steady state over two dosing intervals (- -, test formulation u, reference formulation). C, After oral administration of two different lots of a 180-mg once daily sustained-release formulation to 48 normal volunteers in a cross-over design study and measured at steady state new manufacturing site n, reference manufacturing site).

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