Anna Klugman (former Penkina) will defend her doctoral thesis „Functionality related characterization of pretreated wood lignin, cellulose and polyvinylpyrrolidone for pharmaceutical applications“ on 1 September 2015 at 15.00 in the Faculty of Medicine (Ravila 19-1038).
Supervisors: Professor Jyrki Tapio Heinämäki, dr. pharm., University of Tartu, Department of Pharmacy; Senior Research Fellow Karin Kogermann, PhD, University of Tartu, Department of Pharmacy
Opponent: Associate Professor Ossi Korhonen, PhD Pharm, University of Eastern Finland (Finland).
Medicinal products consist of an active therapeutical ingredient and usually a number of excipients. Excipient is defined as any constituent of a medicinal product that is not an active substance. Today, pharmaceutical excipients can not anymore be considered as inert or inactive compounds. Excipients usually make up the major portion of the pharmaceutical formulation. Thus, excipient physical and chemical property variation is one of the most important input variables that can impact the manufacturing process. Additionally, it is well-known that the properties and performance of the final pharmaceutical dosage form are highly dependent on the physical and chemical properties of the excipients.
The design and isolation of new biomaterials for excipients in pharmaceutical systems have created much interest in recent years. Despite of extensive research, however, virtually no new excipient has been introduced past twenty years. Lignocelluloses and lignin are side-products in the paper pulp manufacturing process, and they are readily available and cheap but have not been investigated as excipients in pharmaceutical applications. It was an object of the present PhD research work to investigate the applicability and the functionality related characteristics of pretreated cellulose and lignin as new excipients in pharmaceutical solid dosage manufacturing. The physicochemical and functionality related characteristics of the present biomaterials were investigated in association with (1) direct compression tablets (to study tablet compaction behaviour), (2) oral solid dispersions (to enhance the solubility of poorly water-soluble drugs), and (3) polymeric films intended for solid dosage form coatings (to evaluate the effects of lignification on the mechanical properties of the films).
It was found that the physicochemical and functionality-related characteristics of pretreated cellulose and lignin are suitable for using them as excipients in the pharmaceutical formulations. However, the present thesis represents the very first steps on a way of exploring the functionality-related characteristics and applications of new biomaterials. Further studies are needed in order to find out their actual utilization in the pharmaceutical manufacturing processes and final formulations.