Pharmaceutica Analytica Acta

Lipid emulsions (LE) and aqueous lecithin dispersions (WLD) as parenteral carriers for poorly soluble drugs

4^th International Conference and Exhibition on Pharmaceutics & Novel Drug Delivery Systems

March 24-26, 2014 Hilton San Antonio Airport, San Antonio, USA

Dorota Watrobska-Swietlikowska and MarcinPlaczek

Posters: Pharmaceut Anal Acta

Abstract:

Many active substances used as drugs are poorly water soluble. In order to administer these drugs in the form of solution (such a form is required e.g. for intravenous application) usually to the formulation, co-solvents or artificial surfactants are added. These excipients can be substituted by natural and biodegradable lipid substances - phospholipids and oils, which are used for years parenterally. The aim of the work was to characterize LE and WLD as potential parenteral carriers used for solubilization of two model drugs: carbamazepine and hydrocortisone. Both formulations (LE and WLD) contained glycerol (2.5%) and phospholipids (5% or 10% in WDL or 1.2%, 2.4% and 5% in LE), while LE also contained soya-bean oil (10%). Submicron dispersion of the oil (LE) and lecithin particles (WLD) were obtained by multi-stage homogenization process and the sterility of the formulations was acquired by autoclaving. In order to characterize the carriers, different physicochemical properties were tested (pH and osmotic pressure of the formulation, Zeta-potential, size and polydispersity of the particles). To determine the solubility of drugs in the tested formulations, active substances were introduced into LE or WLD and mixed at room temperature. After 24 h, suspensions were centrifuged, filtered and the drug concentration was analyzed by HPLC. Physicochemical tests indicated that both LE and WLD fulfill the requirements of the carrier intended for parenteral application. It was also confirmed that the solubility of carbamazepine and hydrocortisone in WDL or LE is higher compared to water. Solubility of hydrocortisone increased from 0.3 mg/ml (water) to 0.9 mg/ml(LE containing 1.2% of lecithin and 10% of the oil) and to 2 mg/ml (WLD containing 5% of egg-lecithin). Also the solubility of carbamazepine in WDL was better than in LE, even if both formulations contained the same lecithin concentration (5%). It was also noticed that regardless of the type of carrier (LE or WLD) and of the type of surfactant (egg, soya-bean lecithin or pure phospholipids) the increase in phospholipid concentration caused the increase in tested drug?s solubility.

Biography :

Dorota Watrobska-Swietlikowska completed his Ph.D. at the age of 28 years from Medical University of Gdansk. She is the Scientist at Department of Pharmaceutical Technology of Medical University. She has published 4 papers wherein two of them are in reputed journals. She collaborated with hospitals for studying the physical stability of parenteral admixtures with high electrolyte concentrations.