Sizable market:
New percutaneous patches have only emerged within the last decade or so. In 1980 the first motion sickness drug was for aviation sickness but was not easily taken as an oral medicine. Today there are six types of transdermal patches on sale: nicotine patches for smokers, patches for cardiac disease, high blood pressure, estrogen regulation and pain relief, and the above mentioned anti-motion-sickness patches. Last year the global market in nicotine patches alone was worth some US$750 million.
In the ROC, research into the new transdermal patches started relatively late. It was introduced here about three years ago by Daniel Cheng, a returning Chinese researcher who had been involved in related work during his studies in America. Two years ago the Industrial Technology Research institute (ITRI) set up an experimental plant under Cheng to begin formal research.
According to Cheng, the transdermal patch is destined to be a very successful product. The American market for skin patches is growing at a rate of 30 percent annually, and the global potential is vast. "There are 50 million smokers in America, 25 million of whom want to quit" says Cheng. Mainland China alone has 300 million smokers, many of whom must want to stop smoking. People often fail to give up the habit for lack of an effective method, but with simple, handy new transdermal patches containing minute quantities of nicotine to satisfy the craving, they may have a better chance of success.
Seeking for strong potential:
According to data from the Directorate-General of Budget, Accounting and Statistics, Executive Yuan, the proportion of over-65s in the Taiwan region will reach 7.1 percent next year, meaning that the ROC meets the United Nations definition for an elderly society. The future will inevitably bring an increase in rates of chronic disease, and transdermal patches can provide a more effective, simpler means of medical treatment.
"We feel very positive about this market," says Hsu Te-man, deputy general manager of Hsin-tung Pharmaceuticals, which is already concentrating on transdermal patches as its principle future market. After conducting market research the company decided to enter the field early, and to back ITRI's plan with investment and support.
Of course, ITRI does not have to start the research process from scratch, because of products that have already been successfully developed in the US which can serve as a reference. But there is no point in developing products identical to those in America.
"Of course they will be different," says Daniel Cheng emphatically. The transdermal patches undergoing research and development in the ROC will be high-technology products with distinct Chinese characteristics, hence the name: high-tech dogskin plaster.
A product with distinct Chinese characteristics:
According to Cheng, the name "high-tech dogskin plaster" works on two levels. "High-tech" indicates a transdermal patch that is unlike traditional dogskin plasters, which have uneven efficacy, and cannot be properly analyzed for active constituents.
"'Dogskin plaster' on the other hand, indicates the distinct Chinese characteristics of the patch," says Cheng. Some of the products currently undergoing development will be based mainly on Chinese medical ingredients.
He believes that research and development for the new medicines should seek for areas where China's already has strong potential, and not simply follow behind the West. According to Cheng, drugs developed in the West tend to be more potent to match the build of the people. Also, Westerners are more prone to cardiac disease, so transdermal patches for treating angina have already been developed. In the Orient, however, liver disease is more prevalent, so there is clearly a greater need for transdermal patches designed to treat liver ailments.
If new Chinese-medicine-based transdermal patches can be developed specially for use in the East, the result will be a highly marketable product. "Thousands of years ago our ancestors invented dogskin plasters with medicine that was absorbed through the skin, and there is a lot that we can learn from them," says Cheng. He elaborates: The most important element of a transdermal patch is the substance which promotes absorption of the medicine through the skin. Western drugs are not as efficacious as Chinese medicine at this task. Western medicine even utilizes organic solvents to promote absorption, which can easily harm the user. In contrast, Chinese dogskin plasters mostly contain natural herbal promoters such as liquorice, which are extremely mild. By combining the strengths of Chinese and Western medicine, we could make transdermal patches become our first successfully developed new international medical product.
A meeting point between Chinese and Western medicine?
"This could also be a point where Chinese and Western medicine meet up," adds Cheng. Western transdermal patches are very convenient in that they can be placed anywhere on the body, but it is possible that they could prove even more effective when combined with theories from Chinese medicine concerning acupoints and channels of ch'i.
Cheng is very confident about the development of high-tech dogskin plasters with Chinese characteristics, and expects to see results within the next two years. But there are observers who maintain a cautious attitude.
Liu Cheng-hsiung, associate professor in pharmacology at the Institute of Chinese Medicine, has a detailed knowledge about traditional Chinese transdermal plasters. He explains that skin patch medication dates back to ancient China; so long ago that it is impossible to say exactly when it first emerged. In Chinese medicine, "salve" preparations are sorted into those which are applied externally and those which are taken internally. Transdermal patches are classed as an "external salve," and have wide-ranging use in treating wounds and running sores.
Contents difficult to analyze:
"For example, 'gold-thread plaster' appears in ancient Chinese medical volumes," says Liu.
However, many of the ingredients used in Chinese drugs are natural, unlike in Western medicine where chemical compounds predominate. Consequently, it is often difficult to analyze the constituents of Chinese drugs. "For example," says Liu Cheng-hsiung, "research has shown that liquorice is an excellent absorption promoter in transdermal patches, but there is no way to prove the active components." Even when you have a drug that does the job, it is impossible to convince the international medical world without a report showing scientific analysis of the constituents.
Associate Professor Liu is not optimistic about producing high-technology transdermal patches through scientific analysis of Chinese pharmaceutical constituents. It is "very difficult," he says, to advance the level of analysis by even the slightest degree.
Wang Chia-hung, head of the department of respiratory diseases at Taiwan Veteran's General Hospital, is one of those involved in the ITRI's transdermal patch research and development project. He takes a more neutral stance on the potential for development. Wang says that Taiwan Veterans' General Hospital and the ITRI are working together on a project to produce asthma patches: "The main thing here is to adapt the existing medication." Asthma is currently treated by oral drugs and inhalers, though mainly by the latter method, which introduces medicine directly into the respiratory tract and allows for around one tenth the dosage necessary in the oral type. The ITRI's plan is to adapt existing asthma drugs for transdermal use. "It's still too early to say whether it will be successful or improve on the traditional type," says Wang.
A matter of confidence:
Cheng chien-hsin is not dissuaded by these different views. He recognizes that component analysis of Chinese medicine is a real bottleneck, and that adapting existing medication is not guaranteed to succeed. "But I am confident," he says, having returned with his family to settle in Taiwan precisely on account of transdermal patches, after 14 years studying and working in the US, including long experience in a plant producing the patches. Seeking to break through this research bottleneck, Cheng is planning a visit next year to the heartland of Chinese medicine studies--mainland China.
There are those who are optimistic, and those who are pessimistic, which is quite normal at the high-technology level of research and development. Time will tell what the outcome is, but the high-tech dogskin plaster--a name which is both funny and audacious--should be worth the wait.
[Picture Caption]
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Dogskin plasters, common devices in traditional Chinese medicine, may go high-tech in the not-so-distant future.
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How many are the maladies of the office worker! When dizzy with tired eyes in the future, just stick on a patch on the right spot and--presto! --you'll be reinvigorated.
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If these patches are designed in accordance with the Chinese medical principles of acupoints and channels of ch'i, they may be even more effective. (Sinorama file photo)
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Currently there are about six new-style patches on the market worldwide, and there are more than 150 now undergoing research and development.
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Daniel Cheng is a major researcher of these patches in the R.O.C. Though some are pessimistic about the future of these patches, he is full of confidence.
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