Solubility Enhancement of Poor Water Soluble Drugs by Solid Dispersion: A Review

Abstract

The solubility behavior of drugs remains one of the most exigent aspects in formulation development. With the advent of combinatorial chemistry and high throughput screening, the number of poorly water soluble compounds has dramatically increased. Among all the newly discovered chemical entities, about 40-45% drugs fail to reach market due to their poor water solubility. Because of solubility problem, bioavailability of drugs gets affected and hence solubility enhancement becomes necessary. Solid dispersions have attracted considerable interest as an efficient means of improving the dissolution rate and hence the bioavailability of drugs. Therefore, the application of this technique proves to be an important stratagem for pharmaceutical companies. However, the in - depth knowledge of the solid dispersion is desired for the scale up of formulation, from laboratory scale to industrial scale. There are various methods available to improve the solubility of the new drug in which solid dispersion emerged promising. A Solid dispersion generally composed of two components- the drug and the polymer matrix. Hence, this approach is expected to form a basis for the commercialization of many poorly water-soluble and water-insoluble drugs in their solid-dispersion formulations in the near future. This article reviews the various preparation techniques, carriers used, advantages and limitations of solid dispersions and compiles some of the recent advances.
 Keywords: Bioavailability, Solid Dispersion, Hydrophilic carriers, Polyethylene glycol.

Solid Dispersions of Biologically Active Substances

“…Thus, the above statement allows us to state that SD is used quite widely in medicine and there are many reviews about this, in addition to research articles [13][14][15][16]. However, there are almost no studies on the use of SD in the field of plant protection, except for the work of the author of this review.…”

“…It's known that SD is the dispersion of one or more active ingredients in a carrier or matrix in a solid state. There are various methods for obtaining SD, which can be divided into the following [5] : -varieties of methods using organic solvents (Kneading Method, Solvent melting method, Spray-Drying Method, Gel entrapment technique); -the methods of Melting /Fusion method; -the method of co -grinding; -the method of supercritical fluid.…”

Solid Dispersions of Anthelmintics and Plant Protection Preparations

“…It is known that SD is the dispersion of one or more active ingredients in a carrier or matrix in a solid state. There are various methods for obtaining SD, which can be divided into the following [5]: Usually, SD are widely used in medicine [6][7][8][9][10], because these systems can provide many additional advantages:…”

“…Thus, the above statement allowed for stating that SD is used quite widely in medicine and there are many reviews about this, in addition to research articles [2][3][4][5][13][14][15][16]. However, the use of SD for improving plant protection products, in particular, in the development of innovative protectants for cereals and potatoes, does not have the same great achievements, namely, only a few studies on the use of nanopesticides in the field of plant protection are known [17][18][19][20].…”

Microwave-Induced In Situ Amorphization: A New Strategy for Tackling the Stability Issue of Amorphous Solid Dispersions

“…ASDs are regarded as one of the most promising and efficient techniques for the solubilization of poorly water soluble APIs [3,4]. ASDs have been widely studied, and there have been a huge number of high quality reviews summarizing the development and research progress of ASDs [5][6][7][8][9][10][11]. Thus, this review only provides a very brief introduction to ASDs, which leads to the main focus of the review, i.e., microwave induced in situ amorphization, as an upcoming approach to solving the physical stability concerns of ASDs.…”