The Fasted State Simulated Intestinal Fluid (FaSSIF) is a specialized medium used in pharmaceutical research to mimic the conditions of the fasted state in the human small intestine. It serves as a valuable tool for evaluating the dissolution behavior of drug formulations and assessing their potential for absorption within the gastrointestinal tract. FaSSIF is composed of specific components to replicate the physiological environment of the small intestine during the fasted state.
The formulation of FaSSIF includes sodium taurocholate, lecithin, NaOH, NaH2PO4.H2O, NaCl, and purified water. Sodium taurocholate, a bile salt, is present at a concentration of 3mM, contributing to the solubilization of lipophilic compounds, and emulating the natural bile environment. Lecithin, at a concentration of 0.75 mM, aids in forming micelles, which facilitate the dissolution and absorption of lipids. The pH of the medium is set at 6.50, resembling the pH of the small intestine during fasting, and its osmolality is around 270 mOsmol/kg, simulating the osmotic conditions of the intestinal fluid.
The preparation of blank FaSSIF involves dissolving specific quantities of NaOH (pellets), NaH2PO4.H2O (or anhydrous NaH2PO4), and NaCl in purified water. This mixture is adjusted to precisely pH 6.5 using either 1 N NaOH or 1 N HCl. This step forms the foundation of the FaSSIF medium.
To create the complete FaSSIF, sodium taurocholate is dissolved in 500 mL of the previously prepared blank FaSSIF. An emulsion is then formed by adding a solution containing 100 mg/mL of lecithin in methylene chloride. The methylene chloride is subsequently removed through vacuum evaporation at approximately 40°C. This process involves two stages of vacuum, initially at 250 mbar for fifteen minutes, followed by 100 mbar for another fifteen minutes. The result of this meticulous procedure is a clear, micellar solution without any lingering odor of methylene chloride. After cooling to room temperature, the volume is adjusted to 2 L using blank FaSSIF.
For conducting dissolution tests, a recommended volume of 500 mL of the prepared FaSSIF is employed. The uniqueness of FaSSIF lies in its ability to replicate the complex interplay of bile salts, lipids, and other physicochemical factors present in the fasted small intestine. This facilitates accurate predictions about a drug formulation's behavior under realistic gastrointestinal conditions, aiding pharmaceutical researchers in optimizing drug delivery systems for enhanced absorption and efficacy.
Read also:
Resource Person: Prakash Amate
){kind=link}