Dr. Yang Zhijun develops novel nano-vesicles for controlled release of medication for pulmonary diseases via inhalation

March 20, 2015

Dr. Yang Zhijun, Associate Professor of the Teaching and Research Division, has applied nanotechnology to develop a novel formulation of dehydrated lipid vesicles for inhalation administration of drugs for the treatment of pulmonary diseases, with the effect of the active pharmaceutical ingredients (APIs) lasting up to 72 hours in the lungs.  The invention, which has been granted a patent by the State Intellectual Property Office of China, prolongs the therapeutic period of drugs  and reduces the dosage and side effects, and is thus safer for patients.

Asthma, emphysema and respiratory tract sensitivity reaction are common chronic diseases of the respiratory system characterised by continuous constriction of the airway, resulting in symptoms such as coughing and shortness of breath, or, in severe cases, even fatal consequences.  Patients are usually prescribed bronchodilators administered either orally or via injection or inhalation.

Drugs administered orally or via injection are circulated to the heart, brain and other parts of the body through the blood, resulting in various side effects and adverse effects on patients on the one hand and the loss of pharmaceutical ingredients required by the target organs on the other hand.  Patients thus have to take a higher dosage of medication in order to control the disease.  Inhalation is very often the preferred method for drug administration because the direct targeting of drugs to the lungs via the respiratory tract delivers speedy therapeutic effects.  However, since a high dosage of medication is harmful to the membrane of the respiratory tract, patients are usually prescribed a dose every four hours to ensure a sustained therapeutic effect. 

In view of the limitations of existing drugs for respiratory diseases, such as asthma, Dr. Yang launched a study in 2007 to explore a kind of molecule capable of delivering APIs directly to the lungs with a prolonged therapeutic effect.  He used liposome, a tiny natural molecular substance which does not break up easily, to conduct research and animal experiments.  His studies demonstrated a slow transportation rate of pharmaceutical ingredients encapsulated in liposomes and that APIs of drugs were found in the lungs of animals after a lapse of 48 hours, proving its ability to prevent the rapid loss of pharmaceutical ingredients in the lungs or through the blood flow.  The result of the study was published in International Journal of Nanomedicine in 2012.

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