Drug solubility and bioavailability improvement. Possible methods with emphasis on liquisolid systems formulation

Document from the year 2018 in the subject Pharmacology, grade: 1, , course: Pharmaceutical Technology, language: English, abstract: The aim of this book is to provide a brief but comprehensive overview on the issue of drug bioavailability improvement by preparation of a perspective dosage form - liquisolid systems. The introduction chapter about drug solubility and bioavailability is followed by a description of the general methods which could be used to improve drug bioavailability using approaches of chemistry, physical modification, and primarily pharmaceutical technology. Benefits and practical use of each method are documented by examples. The main part of the book is aimed at characterization and description of liquisolid systems (LSS) - perspective dosage form for bioavailability improvement. Elementary principles of LSS formulation are described in detail, e.g. how to perform a preformulation study; how to choose the correct type and amount of excipients; how to evaluate the dosage forms, etc. All the above mentioned principles are documented with practical examples. The book could be used as a textbook for students of natural, medical and pharmaceutical sciences as well as by researchers in this field or industrial area. Contemporary pharmacotherapy is characterized by the increasing amount of active substances that are only poorly soluble in water. This may lead to the limitation of their systemic absorption on oral administration which is closely related to the bioavailability. This category is estimated to include more than forty percent of active substances that are in general use. So far, this poor aqueous solubility has been improved by physical or chemical modification of the active substance. In general, such changes are very expensive and troublesome, often leading to problems in stability, marketing authorization process, or administration comfort of the particular drug. This is one of the reasons why modern pharmaceutical technology has focused on those dosage forms that can increase the bioavailability of some active substances while maintaining suitable stability and administration comfort. Several processes that improve solubility, respectively bioavailability have been described and published. These include micronization, nanocrystals, and formulation of solid dispersions. Only recently, a novel trend has appeared - to take advantage of good solubility of active substances in chosen solvents, that is, to use the active substances in a liquid phase.