www.derpharmachemica.com t ailable online a Av Scholars Research Library Der Pharma Chemica, 2015, 7(8):59-63 (http://derpharmachemica.com/archive.html) ISSN 0975-413X CODEN (USA): PCHHAX 59 www.scholarsresearchlibrary.com Exploring the effect of sodium cholate on serum albumin by intrinsic fluorescence spectroscopic technique Susithra Selvam Department of Chemistry, Vel Tech University, Chennai, India ____________________________________________________________________________________________ ABSTRACT Serum albumin is the transport protein, which carries the drug and drug delivery systems through the blood stream and the drug molecule is delivered at the required site of pathology. Serum albumin is the first biological system which a drug formulation interacts, when an I.V. administered. Hence understanding the interaction between protein and drug delivery system is essential. And also proteins are also being used as drug molecules. The formulation of proteins are challenging owing to their denaturation under certain conditions. A pharmaceutical excipient can be used to stabilize the proteins in their native state. In the present study, the association of bovine serum albumin with a novel bile salt, sodium cholate is carried out. The focus of the study is to analyze the suitability of NaC as a stabilizing agent for serum albumins. Keywords: Bovine serum albumin, Sodium cholate, Bile salts, Absorption, Fluorescence spectroscopy, Aggregates ____________________________________________________________________________________________ INTRODUCTION When a drug is administered into the body, proteins (serum albumin) are the biological systems which primarily associate with the drug delivery media, for the transport of drugs [1,2]. When designing a particular macromolecule as a drug delivery media, it is essential to understand the interaction between these macromolecules and proteins [3- 5]. One of the important biological aggregate used in pharmaceutical formulation as drug delivery media is bile salt aggregates [6-9]. Bile salts are biological compounds that are synthesized from cholesterol in the liver. They are typically composed of a steroidal backbone with one or more alpha oriented hydroxyl groups unconjugated to an anionic chain or tail [10]. Bile salts are widely used as solubilization and disaggregating agents in the pharmaceutical industry [11,12]. In aqueous media, bile salts undergo spontaneous aggregation leading to primary and secondary aggregates involving a step – wise aggregation model [13,14]. The primary aggregates are formed due to hydrophobic interaction between the steroidal back-bone. Secondary micelles are held together by hydrogen bond. In another case, the formulation of therapeutic proteins requires pharmaceutical excipients, which can prevent protein aggregation, precipitation and adsorption to surfaces [15-18]. Bile salt aggregates being able to associate with proteins can be useful in the formulation of proteins. Thus a detailed analysis of their interaction with proteins is of immense interest, which leads to pre-formulation studies of therapeutic proteins. Bovine serum albumin (BSA) is used as the model protein in this study. Among the various bile salts, sodium cholate (NaC), a primary unconjugated bile salt was chosen for the study. Since the serum albumins contain