Since decades polyols play an important role as active ingredients and also as excipients in pharmaceutical formulations.
Polyols as Active Pharmaceutical Ingredients (API)
First medical indication of polyols as active ingredients was the treatment of constipation. Even today polyol solutions are used as enema before examinations of the colon. Nowadays the main indication for polyols as pharmaceutical active is the reduction of brain swelling and acute kidney failure. Here, polyols act as osmotic diuretics and remove excess water out of the body. These life-supporting formulations are administered as infusion solutions and usually contain 10-20% of polyol in sterilised water. Polyols for use as APIs need to correspond to special requirements regarding their purity. These requirements are defined in the European (EP), US (USP) and Japanese(JP) Pharmacopoeias. In addition the manufacturing process of these polyols need to be in accordance with the “current Good Manufacturing Practices” (cGMP). The European polyol manufacturers adhere to these regulations and offer suitable products for the use of polyols as API.
Polyols as excipients
Compared to the use of polyols as API, the volumes of polyols used as excipients are considerably higher. Especially in modern formulations, like consumer friendly lozenges or chewable tablets, polyols have gained popularity due to their sweet taste and tooth-friendliness. But also in conventional tablets the usage of polyols is increasing. Compared to the most commonly used pharmaceutical excipient lactose, polyols have some important advantages:
- More and more active ingredients are derived from biotechnological processes. These actives are often very efficient but also extremely reactive. Polyols do not contain reducing sugars, thus the unwanted reaction between the amino-groups of the active and the reducing sugar (like lactose) can be prevented. In addition, non-hygroscopic polyols are used in case a very water-sensitive API has to be formulated.
- Besides the chemical inertness of polyols, also the functionality in the tablet formulation is of utmost importance. The European polyol suppliers offer their pharmaceutical customers polyols in various particle size ranges and in functionalised granulated or spray-dried forms to facilitate modern pharmaceutical production processes like direct compression.