A cream may have to be thickened or have a component that the skin will absorb readily. The large scale production of complex molecules can be very difficult. Compounds originally isolated from natural products may continue to be harvested. Often natural products are found in nature only in extremely small quantities necessitating a complex synthesis. One route that has been under development more recently is to have compounds produced by genetically engineered micro-organisms or plants.
Drugs have a high value per gram.
As such production techniques can be viable even though they are far more inefficient than those used by bulk chemical producers. Often all possible production techniques are researched even though only one will be put into practice. This is done so that there are no openings for competing corporations to get around a manufacturers patents by using a different technique. Manufacturing regulations have become much more stringent in recent years. It is now also important to determine what by-products will result from production and what environmental impact there will be.