Dr Ian Larson

Dr Ian Larson is a Senior Lecturer in Pharmaceutics and Formulation Science at the Victorian College of Pharmacy (VCP).

In the specific area of nanotechnology, Dr Larson is specialising in making nanoparticles for the oral delivery of active ingredients. This particular area of research represents a novel approach and he is collaborating with Dr Ken Ng, also from Monash's VCP.

"We hear that antioxidants are good for us - like those found in tofu and green tea - but to be of any benefit they need to get into the blood. We set about making biopolymers to form nanoparticles. These protect the antioxidants from the low PH in the gut, and, once there, they can be released slowly into the blood."

Drs Larson and Ng have encapsulated antioxidants in nanoparticles to carry them protected through the gut to be released into the small intestine. The PH balance is different here, and the nanoparticles become leaky and diffuse out. The biopolymers develop muco-adhesive qualities and stick to the walls of the small intestine. They leak their contents directly into cells through which absorption takes place. As a result, the antioxidants are not degraded and are delivered more efficiently.

There are clear benefits to the health of society from the work Dr Larson is conducting. The aim is to incorporate nanoparticles into food stuffs so they are not able to be distinguished. For instance, nanoparticles could be successfully embodied into ingredients used for baking, like flour, or even into spreads, like vegemite. Their absorption would be undetected, something not possible when using particles the size of a grain of rice. Nanoparticles are multi-purpose and easy to use, and facilitate drug delivery.

Dr Larson is collaborating closely with Dr Boyd, at Monash's Institute of Pharmaceutical Sciences, for his studies into liquid crystals. They are investigating the use of liquid crystalline injections which can switch drug release on or off.

Other current research Dr Larson is undertaking is in the area of inhalation medication, particularly with respect to the treatment of asthma. He is exploring the workings of a dry powder inhaler, to improve the effectiveness of the drug delivery. The result should be to make the dosage between 80-90% accurate and will also cut costs.

Selected Publications

Adi, H., Larson, I.C. and Stewart, P.J. Use of milling and wet sieving to produce narrow particle size distributions of lactose monohydrate in the sub-sieve range (2007) Powder Technology 179 95-99.

Adi, H., Larson, I.C. and Stewart, P.J.  Laser diffraction particle sizing of cohesive lactose powders (2007) Powder Technology 179 90-94.

Das, S., Larson, I.C., Young, P. and Stewart, P.J.  The relationship between the performance and surface energy of salmeterol xinafoate powders for inhalation during long term storage at different relative humidity (2007) Proceedings of CHEMECA 2007: Academia and Industry Strengthening the Profession 468-474.

Adi, H., Larson, I.C., Stewart, P.J.  Adhesion and redistribution of salmeterol xinafoate particles in sugar-based mixtures for inhalation (2007)  International Journal of Pharmaceutics 337 229-238.

Dong, Y.D., Larson, I.C., Hanley, T. and Boyd, B.J.  Bulk dispersed aqueous phase behaviour of phytantriol: effect of vitamin E acetate and F127 polymer on liquid crystal nanostructure. (2006) Langmuir 22 9512-9518.

Murphy, B.M., Prescott, S.W. and Larson, I.C. Measurement of lactose crystallinity using Raman spectroscopy (2005)  Journal of Pharmaceutical and Biomedical Analysis 38 186-190.

Islam, N., Stewart, P.J., Larson, I.C. and Hartley, P. Surface roughness contribution of the adhesion force distribution of salmeterol xinafoate on lactose carriers by atomic force microscopy (2005) J Pharm Sci 94(7)1500-1511.

Adi, H., Larson, I.C. and Stewart, P.J.  Influence of the particle size of fine lactose in the dispersion of salmetereol xinafoate from lactose mixtures for inhalation, (2004) Respiratory Drug Delivery IX  2553-556.

Islam, N., Stewart, P.J., Larson, I. C. and Hartley, P. Lactose surface modification by decantation - are drug-fine lactose ratios the key to better dispersion of salmeterol xinafoate from lactose interactive mixtures? (2004) Pharm Res 21(3) 492-499.

Islam, N., Stewart, P.J., Larson, I.C., Hartley, P. Effect of carrier size on the dispersion of Salmeterol Xinafoate from interactive mixtures. (2003). J Pharm. Sci 93(4)1030-1038.

Larson, I.C. and Ralston, J. Atomic Force Microscopy and Colloid Interaction Forces in Encyclopaedia of Surface and Colloid Science (2002)  Marcel Dekker New York Ed: Hubbard, AJ.

Larson, I.C. and Milling, A.J.  Electrical Double Layer Measurements using Atomic Force Microscopy in Surface Characterisation Methods: Principles, Techniques and Applications (1999) Marcel Dekker New York. Ed: Milling, AJ.

Larson, I.C., Drummond, C.J., Chan, D.Y.C. and Grieser, F. Direct Force Measurements between TiO2 Surfaces.  (1993) J Am Chem Soc 115 11885-11890.