Cardamom pods hold potential for natural drug delivery.Researchers in India are exploring the potential for using the pods that hold cardamom seeds for delivering drugs. “These natural shells can be considered as ideal low-cost oral drug delivery carriers,” says Utkarsh Bhutani, who is developing the idea with guidance from Saptarshi Majumdar at the Indian Institute of Technology, Hyderabad. Their work demonstrating the potential of this novel and natural drug delivery vehicle is published in the journal Materials Discovery.
“Transforming cardamom into a drug delivery vehicle requires minimal processing effort and is less expensive than using other biodegradable polymers,” says Majumdar. Tests have shown that the capsules can hold and release drugs with a variety of chemical properties, including “hydrophilic” drugs that are readily water-soluble and “hydrophobic” ones that do not mix well with water. Majumdar suggests that this versatility might allow the oral delivery of some drugs, including anti-cancer therapies, that currently must be delivered intravenously. “Achieving oral delivery could increase patient compliance,” he points out, offering a simple way to achieve the overall success of life-saving drug therapy regimes.
Tests performed in solutions designed to mimic biological fluids revealed some surprising and useful aspects of the manner in which the filled pods give up their drug cargo. As the natural fibrous capsules biodegrade, the quantity of drug released varies directly with the time lapsed after administration. This is a rare and much-sought property for oral drug delivery systems, known as “zero-order kinetics”. It achieves the desired steady, consistent release of a drug rather than a fast initial release followed by a falling off, or a delay then a growing burst of release. Majumdar adds that the desired rate of release is achieved without using the toxic and expensive cross-linker chemicals usually needed to stabilize and maintain the polymers that carry drugs.
Cutting open the pods cleanly, removing the seeds, inserting the drug held within the polymer gel and then resealing the pods is a tricky operation that would be difficult to automate. But Majumdar points out that in countries like India, with a need to create more employment opportunities, a manual production process could be economically feasible and socially useful.
The next key challenge for the researchers is to move on from these promising tests in simulated biological fluids and onto more realistic tests in animals. Collaboration with the existing cardamom industry could see a currently unused waste product transformed into a valuable resource for the pharmaceutical industry.
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Bhutani, U. and Majumdar, S.: "Natural fibre envelope for cross-linked and non-cross-linked hydrogel-drug conjugates: Innovative design for oral drug delivery," Materials Discovery (2017)