M. Teresa Carvajal, Ph.D. Assistant Professor of Industrial and Physical Pharmacy Phone: (765) 496-6438 Fax: (765) 494-6545 E-mail: tcarvaja@purdue.edu Full directory listing

Specialization: Pharmaceutical Technology: 1) Surface material science including: investigation into surface energy & particle interactions for dry powders; 2) Surface assessment & stability of processed particles, 3) Formulation of microparticles for inhalation therapy.

Education

Research: Pharmaceutical Technology: 1) Surface material science including: investigation into surface energy & particle interactions for dry powders; 2) Surface assessment & stability of processed particles, 3) Formulation of microparticles for inhalation therapy.

Surface Science in Pharmaceutical Materials is the objective of our research. We are mainly focusing in exploration of and exploiting the physical and chemical factors that influence particle interactions, cohesion-adhesion, in pharmaceutical materials and dosage forms. We apply the emerging advanced high resolution surface analytical technologies available for our studies including IGC, water vapor sorption (VTI), Isothermal microcalorimetry, BET, AFM, spectroscopic and particle size analyzers. All these techniques have provided direct characterization at the microscopic (molecular) level of the surface induced disorder of processed particle, and in some instances, real-time visualization and monitoring of the surface stability by variations in temperature and /or moisture. The influence of water on particle interactions may lead to physical changes and chemical reactivity of composites. These studies are important in that they will lead to better understanding of the behavior and stability of the pharmaceutical materials when exposed to conditions of temperature, moisture and pressure, and eventually finding new approaches to stabilizing materials at the macroscopic (bulk) level for improved functionality of powders and ultimately possible strategies for formulating dosage forms with optimum performance. Recently, we are in the process of starting a major potential new study for the production of solid drug particles, either crystalline or amorphous nature, incorporated in polymers and by making use of etching techniques for surface microfabrication of the materials with greater control of the physico-chemical properties and stability. In general, all these approaches will provide a desired drug form for dry powders for inhalation and topical/transdermal formulations, and for understanding and controlling: materials, formulation and processes to comply with the FDA PAT initiative of quality-by-design.

Activities Pharmaceutical Surface Research Group

• Excipient-induced physical changes and excipient-functionality for pharmaceuticals and food fields
• Physical and chemical stability during processing powder blends dry or on wet granulation
• Role of water at the surface of powders: interactions and mechanisms (adsorption, condensation, etc)
• Develop engineered particles by crystallization or precipitation procedures as an alternative approach to formulate dry powders for inhalation
• Powder technology issues, the behavior of composites or powders and powder blends during development and manufacturing such as content uniformity, segregation and agglomeration, being the result of heterogeneities on surface forces (particle cohesion-adhesion).

Representative Publications

1) Sai P. Chamarthy, Rodolfo Pinal and M. Teresa Carvajal. Elucidating Raw Material Variability-Importance of Surface Properties and Functionality in Pharmaceutical Powders. AAPS PharmSciTech. DOI: 10.1208/s12249-009-9267-5. Published online date: 5 June 2009

2) M. Abiad, M.T. Carvajal and O. Campanella. A review on methods and theories to describe the glass transition phenomenon: applications in food and pharmaceutical products. Food Engineering Reviews DOI 10.1007/s12393-009-9009-1 (2009).

3) Tao Feng, Simon Bates and M. Teresa Carvajal. Toward Understanding the Crystal Defects Formation and Evolution during the Cryogenic Milling of Griseofulvin. Int. J. Pharm. 367(1-2):16-19 (2009).

4) Aurélie Barth, Ziyang Su, Karl Wood, Stephen R. Byrn and M. Teresa Carvajal. Counterfeit Medication Determination Via Impurity Mapping. Tablets and Capsules October pp. 1-5 (2009).

5) Yinyan Zhao, Fuyue Li, M. Teresa Carvajal , Michael T. Harris. Interactions between bovine serum albumin and alginate: An evaluation of alginate as a protein encapsulation carrier. Journal of Colloid and Interface Science 332(2):345-353 (2009).

6) David R. Ely, Markus Thommes and M. Teresa Carvajal *.Analysis of the Effects of Particle Size and Densification on NIR Spectra. Colloids and Surfaces A: Physicochemical and Engineering Aspects 331(1-2):63-67(2008).

7) Tao Feng, Rodolfo Pinal and M. Teresa Carvajal *. Process Induced Disorder in Crystalline Materials: Differentiating Defective Crystals from the Amorphous Form of Griseofulvin. J. Pharm. Sci. 97 (8): 3207-3221 (2008).

8) Andrew Otte, Cara T. Smith, Masaru P. Rao, and M. Teresa Carvajal *. Micromolding as a potential manufacturing route for dry powder formulations. Inhalation 2 (3):10-12 (2008).

9) A. Otte, A. Lityo, Sai P. Chamarthy, J. Langridge, C. Wassgren and M. T. Carvajal *. "."Understanding the Agglomeration Tendencies of Powders for Inhalation". Respiratory Drug Delivery XI Proceedings , R.N. Dalby, P.R. Byron and S.J. Farr, Eds. Interpharm Press, Buffalo Grove, IL, pp 719-721 (2008).

10) S.P. Chamarthy, A. Otte, D. Ely, J. Langridge, O.K. Valet, and M.T. Carvajal *, "Why powders don't behave the way we want? - Understanding the surface of pharmaceutical powders and its effectiveness in functionality" in Proceedings of Respiratory Drug Delivery XI (2007), Richard N. Dalby, Peter R. Byron, and J. Peart, eds., Interpharm Press, Buffalo Grove, Illinois.

Curriculum Vitae

Click here for a full CV for M. Teresa Carvajal. (an Adobe Acrobat file)