Supercritical fluid extraction—Supercritical fluid chroomatography for analysts of a prostglandin: HPMC dispersion

Extraction of pharmaceuticals using pressurised carbon dioxide

This paper reviews the applications of super- and sub-critical carbon dioxide for the extraction of pharmaceuticals from various matrices. The matrices covered are divided into the following types: animal feed, formulations, biological and miscellaneous, with various sub-divisions as appropriate. The polar nature of most pharmaceuticals often precludes the use of carbon dioxide only, so it is common to find the addition of a more polar solvent, as modifier. As the majority of sample types covered are solid, little if any pre-treatment is required, with the exception of grinding, prior to insertion in the sample extraction cell. For liquid-type matrices, sample pre-treatment is the normal. Often this may involve adsorption on an inert support e.g. Celite or diatomaceous earth, or immobilisation on a functionalised silica surface, e.g. C18. The later may take the form of a solid phase extraction cartridge or disk. An attempt has also been made to sample from liquid matrices directly using a modified extraction cell. The variety of sample types, matrices and analyte polarity places stringent requirements on the use of pressurised carbon dioxide. Its potential for effective recovery is examined in this review.

Supercritical fluid extraction method development for extraction of an experimental HIV protease inhibitor drug from animal feed

Supercritical fluid extraction (SFE) was evaluated as a sample preparation procedure for the recovery of experimental drugs from animal feed preparations that are generated during long-term toxicology studies. A commercially available supercritical fluid extractor was utilized to develop and validate an off-line procedure for the recovery of an experimental HIV protease inhibitor drug from animal feed. Extracts were analyzed with a conventional reversed-phase HPLC method. Elements of the SFE method developed that are described include optimization of the system temperature and selection of the extraction media modifier. The study emphasized the performance of two-day precision and accuracy studies. Precision and accuracy studies were carried out with SC-52151 levels of 0.05, 0.1 and 1.0% (w/w) and used an internal standard quantitation format. Also, the study utilized a relatively large analytical scale extraction vessel size of 10 ml to accomodate 6 g animal feed samples.