| Abstract: | The second part of the XXth century have seen the creation of new systems of administration for drugs, including delayed formulation systems or prolonged-release formulations (PRF). It is first within the industry, and mainly in the USA, that such new formulations were developed, with the purpose to increase the duration of action for pharmaceutical active principles. Several approaches were proposed and developed, jointly with more and more sophisticated evaluation techniques. In France, PRF market increased progressively during the 1980's; it then decreased because of more severe restrictions by health authorities for new drug approvals. In French specialty reference book (Vidal) included 518 PRF in the year 2000, from which 121 were tablets and 118 were hard gelatine capsules. |
