Swallowable capsule technology: current perspectives and future directions

 

 Buy Article Permissions and Reprints

Introduction

The mammalian gut is a complex ecosystem, which is colonized by a diverse collection of microbes [1]. For many years this ecosystem has been treated as a black box. Firstly, it is very difficult to obtain accurate data on what is happening throughout the intestinal tract, and secondly, many of the bacteria in the gut cannot be cultured in vitro. Whereas the latter issue is a technical matter for microbiologists, the former is an issue due to current approaches by gastroenterologists to obtain data on the physiology of the gut. The ideal solution to this problem would be a system that would either collect or measure in situ, without the need to change or perturb the gut ecosystem. This approach would provide information for the clinician on the “state of the gut,” and whether it differs from what would be considered a normal gut. The swallowable capsule has the potential to provide this capability. These tiny devices can noninvasively access the gut. The devices can visualize the gut in the form of capsule endoscopes. Recent advances in the area are resulting in capsules with controlled movement, from either magnetic or electrical stimulation. Capsules with useful features, such as chemical sensors and dissolved gas sensors, are being developed to obtain more specific information on the gut. These capabilities can be used in addition to, or eventually instead of, the traditional markers of urine, blood, and feces.

References

• 1 Eckburg P B, Bik E M, Bernstein C N. et al . Diversity of the human intestinal microbial flora.  Science. 2005;  308 1635-1638
  CrossrefPubMedGoogle Scholar
• 2 Clear N J, Milton A, Humphrey M. et al . Evaluation of the InteliSite capsule to deliver theophylline and frusemide tablets to the small intestine and colon.  Eur J Pharm Sci. 2001;  13 375-384
  CrossrefPubMedGoogle Scholar
• 3 Pithvala Y K, Heizer W D, Parr A F. et al . Use of the InteliSite capsule to study randitine absorption from various sites within the human intestinal tract.  Pharm Res. 1998;  15 1869-1875
  CrossrefPubMedGoogle Scholar
• 4 Wilding I R, Hirst P, Connor A. Development of a new engineering-based capsule for human drug absorption studies.  Pharm Sci Tech Today. 2000;  3 385-392
  CrossrefPubMedGoogle Scholar
• 5 McDowell A, Nicoll J J, McLeod B J. et al . Gastrointestinal transit in the common bushtail possum measured by gamma scintigraphy.  Int J Pharmaceutics. 2005;  302 125-132
  CrossrefPubMedGoogle Scholar
• 6 Ofori-Kwakye K, Fell J T, Sharma H L. et al . Gamma scintigraphic evaluation of film-coated tablets intended for colonic or biphasic release.  Int J Pharmaceutics. 2004;  270 307-313
  CrossrefPubMedGoogle Scholar
• 7 Sakkinen M, Marvola J, Kanerva H. et al . Scintigraphic verification of adherence of a chitosan formulation to the human esophagus.  Eur J Pharm Biopharm. 2004;  57 133-143
  PubMedGoogle Scholar
• 8 Wilding I R, Coupe A J, Davis S S. The role of gamma-scintigraphy in oral drug delivery.  Adv Drug Deliv Rev. 2001;  46 103-124
  CrossrefPubMedGoogle Scholar
• 9 Davis S S, Hardy J G, Newman S P. et al . Gamma scintigraphy in the evaluation of pharmaceutical dosage forms.  Eur J Nucl Med. 1992;  19 971-986
  PubMedGoogle Scholar
• 10 Casper R A, McCartney M L, Jochem W J. et al .Medical capsule for transferring substances to or from the alimentary canal via sleeve valved apertures under remote control. United States patent 5,170, 801. 1992 Dec 15. 
  Google Scholar
• 11 Houzego P J, Morgan P N, Hirst P H. et al .Ingestible device. United States patent 6,632,216 B2. 2003 Oct 14. 
  Google Scholar
• 12 Tang T B, Johannessen E A, Wang L. et al . Towards a miniature wireless integrated multisensor microsystem for industrial and biomedical applications.  IEEE Sensors Journal. 2002;  2 628-635
  CrossrefPubMedGoogle Scholar
• 13 Johannessen E A, Wang L, Wyse C. et al . Biocompatibility of a Lab-on-a-Pill sensor in artificial gastrointestinal environments.  IEEE Trans Biomed Eng. 2006;  53 2333-2340
  CrossrefPubMedGoogle Scholar
• 14 Johannessen E A, Wang L, Cui L. et al . Implementation of multichannel sensors for remote biomedical measurements in a Microsystems format.  IEEE Trans Biomed Eng. 2004;  51 525-535
  CrossrefPubMedGoogle Scholar
• 15 Allison E, Kiraly Z, Springer G. et al .Endocapsule. WO 2006/045011 A2. 2006 Apr 27. 
  Google Scholar
• 16 Fiorucci S, Distrutti E, Cirino G. et al . The emerging roles of hydrogen sulfide in the gastrointestinal tract and liver.  Gastroenterology. 2006;  131 259-271
  CrossrefPubMedGoogle Scholar
• 17 Wallace J L. Hydrogen sulphide-releasing anti-inflammatory drugs.  Trends Pharmacol Sci. 2007;  10 501-505
  PubMedGoogle Scholar
• 18 Kim B, Lee S, Park J H, Park J. Design and fabrication of a locomotive mechanism for capsule-type endoscopes using shape memory alloys (SMAs).  IEEE Trans Mechatronics. 2005;  10 77-86
  PubMedGoogle Scholar
• 19 Iddan G J. Self-propelled device. United States patent 6,958,034 B2. 2005 Oct 25. 
  Google Scholar
• 20 Mosse C A, Mills T N, Appleyard M N. et al . Electrical stimulation for propelling endoscopes.  Gastrointest Endosc. 2001;  54 79-83
  CrossrefPubMedGoogle Scholar
• 21 Carpi F, Galbiati S, Carpi A. Controlled navigation of endoscopic capsules: concept and preliminary experimental investigations.  IEE Trans Biomed Eng. 2007;  54 2028-2036
  CrossrefPubMedGoogle Scholar
• 22 Uehara A, Hoshina K. Capsule endoscope NORIKA system.  Minim Invasive Ther Allied Technol. 2003;  12 227-234
  CrossrefPubMedGoogle Scholar
• 23 Kusuda Y. A further step beyond wireless capsule endoscopy.  Sensor Rev. 2005;  25 259-260
  CrossrefPubMedGoogle Scholar

J. R. MarchesiMD 

School of Biosciences
Cardiff University

Museum Avenue
Cardiff CF10 3AT
UK

Fax: +44-29-20874116

Email: marchesijr@cardiff.ac.uk