Abstract
IUPAC (The International Union of Pure and Applied Chemistry) defines solubility as “the analytical composition of a mixture or solution which is saturated with one of the components of the mixture or solution, expressed in terms of the proportion of the designated component in the designated mixture or solution Solubility can further be defined in a more specific manner, like un-buffered, buffered and intrinsic solubility. Un-buffered solubility means the solubility of a saturated solution of the compound at the final pH of the solution. As a qualitative phenomenon, solubility may be defined as the spontaneous interaction of two or more substances to form a homogenous molecular dispersion. A saturated solution is one in which the solute is in equilibrium with the solvent. The solubility of a drug is expressed in terms of various words such as parts, percentage, molarity, molality, volume fraction, mole fraction. Metaxalone is a drug approved by FDA in 1962 as an adjunct to rest, physical therapy and other measures for the relief of discomforts associated with acute painful musculoskeletal conditions. Its exact mechanism is not known, but it may be due to general central nervous system depression. It is considered to be a moderately strong muscle relaxant.
