The Das Laboratory at the School of Pharmacy investigates formulating and delivering medicines using powder inhalers. The emphasis is on improving the effectiveness of medicines for patients with chronic lung conditions.
Associate Professor Shyamal Das leads the laboratory, he is also a senior lecturer in the School of Pharmacy and holds numerous responsibilities in teaching and research. He has received many awards for teaching and research achievements and has cultivated national and international collaborators which enable a variety of opportunities for postgraduate research.
His work has attracted funding from:
- Health Research Council of New Zealand
- Otago Medical Research Council
- New Zealand Pharmacy Education Research Foundation
- University of Otago Research Grants
- Laurenson Award
- School of Pharmacy
- Pharmaceutical industries
The research at the Das Laboratory focuses on drug delivery via the pulmonary / respiratory route using dry powder inhalers (DPI), to improve drug therapy for chronic lung conditions such as:
- Chronic obstructive pulmonary disease (COPD)
- Corona viral infection
- Cystic fibrosis
- Lung infections such as bronchiectasis
Successful delivery of powders to the deeper regions of the lung requires a mechanistic understanding of the factors that influence dispersion of fine powders in air (i.e. aerosolisation). After producing powders using techniques such as spray drying, milling and dry coating, the lab studies their surface properties such as chemistry, particle interactions and physical properties using different solid state characterisation techniques to understand powder behaviour before and after delivery to the lung. Associate Professor Das also investigates efficacy, safety and toxicity using both in vitro and in vivo models.
Das Lab research is building a fundamental understanding of powders with the long-term goal of translating this research into clinical applications.
Das Laboratory COVID-19 research
In response to COVID-19 Associate Professor Das has extended his research to investigate delivery of drugs to the lungs with dry powder inhalers, nebulizers and soft mist inhalers.
The Das Lab has extensive networks with research collaborators across the globe which further enhances the opportunities for research advancement in this pharmaceutical field:
Das Laboratory research collaborators
More about current and past successes from members of the Das Laboratory:
Das Laboratory news
Associate Professor Das describes current research themes:
High dose powders for pulmonary delivery
We focus on both immediate and sustained-release high-dosage powders for treating tuberculosis and other lung infections. Using the spray drying technique to manipulate particle surface chemistry, we have produced powders containing one or more anti-TB drugs, which are highly efficient in delivering up to 80% of a dose. To ensure high dose and sustained release, we produced co-crystals of anti-TB drugs. We then study the stability of the powders.
Prevention and treatment of COVID-19 infection
We have recently focused on research into the prevention and treatment of COVID-19 infection. We are particularly interested in developing an improved hand sanitizer, and developing an inhaled dosage form of drugs and vaccines.
Pulmonary delivery of biologics
We are investigating the pulmonary delivery of micro-RNA as nanocomposite for treating lung diseases, and the delivery of an enzyme to breakdown biofilms in lung infections.
Dissolution of drugs in the lung
We are interested in the influence of lung surfactants on respiratory drug delivery. We have also focused on the influence of lung surfactants and compositions of lung fluids on inhalable powders and clinical studies of high-dose powders for inhalation.
Safety and toxicity of inhaled drugs
We are keen on understanding the safety, toxicity and efficacy of inhaled drugs. We use in vitro cell model as well as in vivo study using rodent model.
Vaping and e-cigarettes
We are also interested in the paradigm shift in social norms for vaping and medicinal cannabis. We have started research on formulations and devices for vaping, and their safety.
Herbal medicines and medicinal cannabis
Das group is interested in formulations and devices as a means of bioactive delivery for drugs derived from herbal sources such as medicinal cannabis.
Powder surface energy characterisation to understand powder de-agglomeration and aerosolisation behaviour
We have developed the method of characterising polar and total surface energy distributions using inverse gas chromatography. Following this, we introduced the concept of powder strength distribution, which has made it possible to understand complex powder de-agglomeration, which was previously difficult to explain.
Postgraduate students research
Within the School of Pharmacy, Associate Professor Das currently supervises a number of postgraduate students.
The team recently volunteered to produce hand sanitiser for the COVID-19 response:
Lecturer and students volunteer time to make sanitiser
The Das Lab also celebrates the achievement of its alumni:
Das Laboratory alumni
Bishal Adhikari, PhD student
Topic: Stability of spray dried powders for inhalation, School of Pharmacy, University of Otago, New Zealand, August 2018 to present.
Bishal Adhikari profile
Rakesh Bastola, PhD student
Topic: Influence of lung surfactant on dissolution of drugs in the lung, School of Pharmacy, University of Otago, New Zealand, September 2019 to present.
Rakesh Bastola profile
Prakash Khadka, PhD student
Topic: Inhaled rifampicin for treatment of tuberculosis - in vitro characterisation and in vivo safety and toxicity studies, School of Pharmacy, University of Otago, New Zealand, February 2017 to present.
Prakash Khadka profile
Rishi Shah, PhD student
Topic: Pulmonary delivery of microRNA for treating lung diseases, School of Pharmacy, University of Otago, New Zealand, October 2019 to present.
Rishi Shah profile
Tushar Saha, PhD student
Topic: Prevention and treatment of COVID-19, School of Pharmacy, University of Otago, New Zealand, November 2019 to present.
Tushar Saha profile
Nicole Wood, BPharm(Hons) student
Topic: Vaping formulations and devices
Nicole Wood profile
Momin, M. A. M., Adhikari, B. R., Sinha, S., Larson, I., & Das, S. C. (2021). Roflumilast powders for chronic obstructive pulmonary disease: Formulation design and the influence of device, inhalation flow rate, and storage relative humidity on aerosolization. Pharmaceutics, 13, 1254. doi: 10.3390/pharmaceutics13081254
Adhikari, B. R., Berzins, K., Fraser-Miller, S. J., Gordon, K. C., & Das, S. C. (2021). Methionine offers superior aerosolization stability over leucine for inhalable high-dose spray-dried kanamycin formulation. Journal of Aerosol Medicine & Pulmonary Drug Delivery, 34(3), (pp. A15). doi: 10.1089/jamp.2021.ab01.abstracts
Ameratunga, R., Woon, S.-T., Steele, R., Snell, R., Medlicott, N., Mears, E., … Das, S., … Quiñones‑Mateu, M. E. (2021). The nose and the stomach play a critical role in the NZACE2-Pātari* (modified ACE2) drug treatment project of SARS-CoV-2 infection. Expert Review of Clinical Immunology. Advance online publication. doi: 10.1080/1744666x.2021.1912596
Khadka, P., Sinha, S., Tucker, I. G., Dummer, J., Hill, P. C., Katare, R., & Das, S. C. (2021). Pharmacokinetics of rifampicin after repeated intra-tracheal administration of amorphous and crystalline powder formulations to Sprague Dawley rats. European Journal of Pharmaceutics & Biopharmaceutics. Advance online publication. doi: 10.1016/j.ejpb.2021.02.011
Khadka, P., Sinha, S., Tucker, I. G., Dummer, J., Hill, P. C., Katare, R., & Das, S. C. (2021). Studies on the safety and the tissue distribution of inhaled high-dose amorphous and crystalline rifampicin in a rat model. International Journal of Pharmaceutics, 597, 120345. doi: 10.1016/j.ijpharm.2021.120345