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Liu X, Wu Y, Liu C, Chen K, Gregersen H. Development of an Ingestible Expandable Capsule for Weight Loss. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2022; 19:16821. [PMID: 36554702 PMCID: PMC9779746 DOI: 10.3390/ijerph192416821] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/14/2022] [Revised: 12/04/2022] [Accepted: 12/10/2022] [Indexed: 06/17/2023]
Abstract
Obesity has grown to epidemic proportions with 2.1 billion people being overweight worldwide. A food-grade expandable capsule named EndoXpand for the treatment of overweight people was designed and developed in this study. EndoXpand consists of an inner expandable material (core), an embracing membrane, and a gelatin capsule shell. It is designed to occupy volume in the stomach and reduce hunger sensation. The occupied volume is changeable over time, dependent on the number of ingested capsules and their degradation time. This will avoid gastric accommodation to constant volume devices as seen in the use of intragastric balloons. Several materials were tested. Collagen casing was selected as the membrane and corn silk was used to tie the membrane. Dried black fungus (Auricularia auricula) was the biological material that expanded most. However, synthesized cellulose-based hydrogel expanded more and was chosen as the optimal expandable core material. The hydrogel-based EndoXpand expanded 72 times after soaking in an acidic environment for 80 min. The corn silk ligations weakened and broke after 3 h. This resulted in release of the expanded material that was designed to easily pass the pylorus and travel down the intestine for digestion or excretion. In conclusion, this study provides design and in vitro proof-of-technology data for a potential groundbreaking approach. Further studies are needed in animal models and human phase I studies.
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Affiliation(s)
- Xingyu Liu
- Graduate School, Chongqing Normal University, Chongqing 401331, China
| | - Yeung Wu
- Department of Surgery, The Chinese University of Hong Kong, Shatin, Hong Kong 999077, China
| | - Chang Liu
- Department of Surgery, The Chinese University of Hong Kong, Shatin, Hong Kong 999077, China
| | - Kaiqi Chen
- Department of Surgery, The Chinese University of Hong Kong, Shatin, Hong Kong 999077, China
| | - Hans Gregersen
- GIOME, California Medical Innovations Institute, San Diego, CA 92121, USA
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2
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Liu X, Steiger C, Lin S, Parada GA, Liu J, Chan HF, Yuk H, Phan NV, Collins J, Tamang S, Traverso G, Zhao X. Ingestible hydrogel device. Nat Commun 2019; 10:493. [PMID: 30700712 PMCID: PMC6353937 DOI: 10.1038/s41467-019-08355-2] [Citation(s) in RCA: 107] [Impact Index Per Article: 21.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2018] [Accepted: 12/20/2018] [Indexed: 11/09/2022] Open
Abstract
Devices that interact with living organisms are typically made of metals, silicon, ceramics, and plastics. Implantation of such devices for long-term monitoring or treatment generally requires invasive procedures. Hydrogels offer new opportunities for human-machine interactions due to their superior mechanical compliance and biocompatibility. Additionally, oral administration, coupled with gastric residency, serves as a non-invasive alternative to implantation. Achieving gastric residency with hydrogels requires the hydrogels to swell very rapidly and to withstand gastric mechanical forces over time. However, high swelling ratio, high swelling speed, and long-term robustness do not coexist in existing hydrogels. Here, we introduce a hydrogel device that can be ingested as a standard-sized pill, swell rapidly into a large soft sphere, and maintain robustness under repeated mechanical loads in the stomach for up to one month. Large animal tests support the exceptional performance of the ingestible hydrogel device for long-term gastric retention and physiological monitoring.
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Affiliation(s)
- Xinyue Liu
- Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
| | - Christoph Steiger
- The David H. Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
- Division of Gastroenterology, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, 02115, USA
| | - Shaoting Lin
- Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
| | - German Alberto Parada
- Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
| | - Ji Liu
- Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
| | - Hon Fai Chan
- Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
- Institute for Tissue Engineering and Regenerative Medicine, The Chinese University of Hong Kong, Hong Kong, China
- School of Biomedical Sciences, The Chinese University of Hong Kong, Hong Kong, China
| | - Hyunwoo Yuk
- Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
| | - Nhi V Phan
- The David H. Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
| | - Joy Collins
- The David H. Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
| | - Siddartha Tamang
- The David H. Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
| | - Giovanni Traverso
- Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
- The David H. Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
- Division of Gastroenterology, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, 02115, USA
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
| | - Xuanhe Zhao
- Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA.
- Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA.
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3
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Altreuter DH, Kirtane AR, Grant T, Kruger C, Traverso G, Bellinger AM. Changing the pill: developments toward the promise of an ultra-long-acting gastroretentive dosage form. Expert Opin Drug Deliv 2018; 15:1189-1198. [PMID: 30392404 DOI: 10.1080/17425247.2018.1544615] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
INTRODUCTION The development of oral sustained release dosage forms has been a longstanding goal due to the potential for ease of administration, improved pharmacokinetics, reduced dosing frequency, and improved adherence. The benefits of multiday single-dose drug delivery are evident in the success and patient adoption of injected and implanted dosage forms. However, in the space of oral medications, all current commercially available gastric resident dosage forms, and most in development, are limited to gastric residence of less than 1 day. AREAS COVERED Reviews of systems to extend gastric residence reveal that 1 day or more residence has been an unmet challenge. New dosage forms are in development that seek to address many of the key physiological and design challenges of long-term gastric retention beyond 24 h and up to a week or longer. The present analysis highlights the design, material considerations and implications of unfolding dosage form systems with ultra-long-term gastric residence. EXPERT OPINION The development of oral dosage forms providing sustained release of high potency medications over days or weeks could transform care, significantly decrease patient burden in chronic disease management and improve outcomes.
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Affiliation(s)
| | - Ameya R Kirtane
- b Department of Chemical Engineering and David H. Koch Institute for Integrative Cancer Research , Massachusetts Institute of Technology , Cambridge , MA , USA
| | | | | | - Giovanni Traverso
- b Department of Chemical Engineering and David H. Koch Institute for Integrative Cancer Research , Massachusetts Institute of Technology , Cambridge , MA , USA.,c Department of Gastroenterology , Brigham and Women's Hospital, Harvard Medical School , Boston , MA , USA.,d Department of Mechanical Engineering , Massachusetts Institute of Technology , Cambridge , MA , USA
| | - Andrew M Bellinger
- a Lyndra Inc , Watertown , MA , USA.,e Department of Cardiovascular Medicine , Brigham and Women's Hospital, Harvard Medical School , Boston , MA , USA
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4
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Development of an oral once-weekly drug delivery system for HIV antiretroviral therapy. Nat Commun 2018; 9:2. [PMID: 29317618 PMCID: PMC5760734 DOI: 10.1038/s41467-017-02294-6] [Citation(s) in RCA: 121] [Impact Index Per Article: 20.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2017] [Accepted: 11/16/2017] [Indexed: 01/07/2023] Open
Abstract
The efficacy of antiretroviral therapy is significantly compromised by medication non-adherence. Long-acting enteral systems that can ease the burden of daily adherence have not yet been developed. Here we describe an oral dosage form composed of distinct drug–polymer matrices which achieved week-long systemic drug levels of the antiretrovirals dolutegravir, rilpivirine and cabotegravir in a pig. Simulations of viral dynamics and patient adherence patterns indicate that such systems would significantly reduce therapeutic failures and epidemiological modelling suggests that using such an intervention prophylactically could avert hundreds of thousands of new HIV cases. In sum, weekly administration of long-acting antiretrovirals via a novel oral dosage form is a promising intervention to help control the HIV epidemic worldwide. Poor adherence to daily antiretrovirals can significantly affect treatment efficacy, but oral long-acting antiretrovirals are currently lacking. Here, the authors develop a once-weekly oral dosage form for anti-HIV drugs, assess its pharmacokinetics in pigs, and model its impact on viral resistance and disease epidemics.
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Bellinger AM, Jafari M, Grant TM, Zhang S, Slater HC, Wenger EA, Mo S, Lee YAL, Mazdiyasni H, Kogan L, Barman R, Cleveland C, Booth L, Bensel T, Minahan D, Hurowitz HM, Tai T, Daily J, Nikolic B, Wood L, Eckhoff PA, Langer R, Traverso G. Oral, ultra-long-lasting drug delivery: Application toward malaria elimination goals. Sci Transl Med 2017; 8:365ra157. [PMID: 27856796 DOI: 10.1126/scitranslmed.aag2374] [Citation(s) in RCA: 152] [Impact Index Per Article: 21.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2016] [Accepted: 10/25/2016] [Indexed: 12/29/2022]
Abstract
Efforts at elimination of scourges, such as malaria, are limited by the logistic challenges of reaching large rural populations and ensuring patient adherence to adequate pharmacologic treatment. We have developed an oral, ultra-long-acting capsule that dissolves in the stomach and deploys a star-shaped dosage form that releases drug while assuming a geometry that prevents passage through the pylorus yet allows passage of food, enabling prolonged gastric residence. This gastric-resident, drug delivery dosage form releases small-molecule drugs for days to weeks and potentially longer. Upon dissolution of the macrostructure, the components can safely pass through the gastrointestinal tract. Clinical, radiographic, and endoscopic evaluation of a swine large-animal model that received these dosage forms showed no evidence of gastrointestinal obstruction or mucosal injury. We generated long-acting formulations for controlled release of ivermectin, a drug that targets malaria-transmitting mosquitoes, in the gastric environment and incorporated these into our dosage form, which then delivered a sustained therapeutic dose of ivermectin for up to 14 days in our swine model. Further, by using mathematical models of malaria transmission that incorporate the lethal effect of ivermectin against malaria-transmitting mosquitoes, we demonstrated that this system will boost the efficacy of mass drug administration toward malaria elimination goals. Encapsulated, gastric-resident dosage forms for ultra-long-acting drug delivery have the potential to revolutionize treatment options for malaria and other diseases that affect large populations around the globe for which treatment adherence is essential for efficacy.
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Affiliation(s)
- Andrew M Bellinger
- Department of Chemical Engineering and Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.,Cardiovascular Division, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA.,Lyndra Inc., Watertown, MA 02472, USA
| | - Mousa Jafari
- Department of Chemical Engineering and Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Tyler M Grant
- Department of Chemical Engineering and Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.,Lyndra Inc., Watertown, MA 02472, USA
| | - Shiyi Zhang
- Department of Chemical Engineering and Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Hannah C Slater
- Department of Infectious Disease Epidemiology, MRC (Medical Research Council) Centre for Outbreak Analysis and Modelling, Imperial College London, London, U.K
| | | | - Stacy Mo
- Department of Chemical Engineering and Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Young-Ah Lucy Lee
- Department of Chemical Engineering and Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Hormoz Mazdiyasni
- Department of Chemical Engineering and Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Lawrence Kogan
- Department of Chemical Engineering and Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Ross Barman
- Department of Chemical Engineering and Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Cody Cleveland
- Department of Chemical Engineering and Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.,Division of Gastroenterology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Lucas Booth
- Department of Chemical Engineering and Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Taylor Bensel
- Department of Chemical Engineering and Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Daniel Minahan
- Department of Chemical Engineering and Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Haley M Hurowitz
- Department of Chemical Engineering and Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Tammy Tai
- Department of Chemical Engineering and Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Johanna Daily
- Division of Infectious Diseases, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Boris Nikolic
- Biomatics Capital, 1107 1st Avenue, Apartment 1305, Seattle, WA 98101, USA
| | - Lowell Wood
- Institute for Disease Modeling, Bellevue, WA 98005, USA
| | | | - Robert Langer
- Department of Chemical Engineering and Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA. .,Media Lab, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.,Institute for Medical Engineering and Science, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Giovanni Traverso
- Department of Chemical Engineering and Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA. .,Division of Gastroenterology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA.,Division of Gastroenterology, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA
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6
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Unfolding type gastroretentive film of Cinnarizine based on ethyl cellulose and hydroxypropylmethyl cellulose. Int J Biol Macromol 2013; 64:347-52. [PMID: 24370473 DOI: 10.1016/j.ijbiomac.2013.12.030] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2013] [Revised: 12/17/2013] [Accepted: 12/18/2013] [Indexed: 11/23/2022]
Abstract
The present work was based on the development and characterization of unfolding type gastro retentive dosage form appropriate for controlled release of Cinnarizine (CNZ), a drug with narrow therapeutic window. The drug loaded polymer film of biological macromolecules, i.e., ethyl cellulose (EC) and hydroxypropylmethyl cellulose (HPMC K15) was folded into hard gelatin capsules. The film was folded in different patterns for characterizing their unfolding behavior. The polymeric film revealed a fast release during the first hour followed by a more gradual drug release during a 12-h period following a non-Fickian diffusion process. Tensile strength of polymeric film was optimized using different amount (0.2-0.7 ml) of polyethylene glycol (PEG 400). Various physical parameters were studied for evaluating their performance as a gastroretentive dosage form. Drug and polymers were found to be compatible as revealed by differential scanning calorimetry (DSC) study and scanning electron micrograph (SEM) study revealed uniform dispersion of CNZ in polymeric matrices. The results indicate that unfolding type gastro retentive drug delivery system holds lots of potential for drug having stability problems in alkaline pH or are which mainly absorbed in acidic pH.
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7
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Burke MD, Staton JS, Vickers AW, Peters EE, Coffin MD. A novel method to radiolabel gastric retentive formulations for gamma scintigraphy assessment. Pharm Res 2007; 24:695-704. [PMID: 17372696 DOI: 10.1007/s11095-006-9189-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2006] [Accepted: 11/06/2006] [Indexed: 10/23/2022]
Abstract
PURPOSE To develop a robust radiolabeling technique to enable evaluation of difficult to radiolabel gastric retentive formulations using gamma scintigraphy. The use of a successful radiolabel will allow accurate assessment of the gastric residence time of the formulations. MATERIALS AND METHODS The retention of two radionuclides, indium ((111)In) and samarium ((153)Sm), with and without further processing to improve radiolabel performance were evaluated in simulated gastric pH in vitro. The most successful formulation from the in vitro screening was further evaluated in preclinical and clinical studies. RESULTS In vitro evaluation revealed significant radionuclide leakage at pH 1.5 for most radiolabeling attempts. Radionuclide leakage at pH 4.5 was less pronounced. The most successful radiolabel was formulated by adsorbing indium chloride onto activated charcoal, followed by entrapment in a cellulose acetate polymer melt. This provided the best radiolabel retention under both pH conditions in vitro. The radiolabel also proved to be successful during preclinical and clinical evaluations, allowing evaluation of gastric retention performance as well as complete gastrointestinal transit. CONCLUSION A simple, yet robust radiolabel was developed for gastric retentive formulations to be evaluated pre-clinically or in a clinical setting by entrapping the radionuclide in an insoluble polymer through a simple polymer melt process.
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Affiliation(s)
- Matthew D Burke
- Product Development, Pharmaceutical Development, GlaxoSmithKline, Research Triangle Park, NC 27709, USA.
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8
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Gröning R, Cloer C, Georgarakis M, Müller RS. Compressed collagen sponges as gastroretentive dosage forms: in vitro and in vivo studies. Eur J Pharm Sci 2006; 30:1-6. [PMID: 17101267 DOI: 10.1016/j.ejps.2006.08.003] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2006] [Revised: 05/17/2006] [Accepted: 08/03/2006] [Indexed: 11/17/2022]
Abstract
The objective of the present investigations was to develop oblong tablets which expand after contact with gastrointestinal fluids within a few minutes to a length of 4-6 cm and which should remain in the stomach for a prolonged period of time due to their size. The tablets were prepared from riboflavin-containing collagen sponges using a computer controlled single punch tablet machine. The collagen material was compressed to oblong tablets with dimensions of 3.5 mm x 9 mm x 18 mm. In vitro investigations were carried out to characterise drug release. The model drug riboflavin was released from the collagen tablets over 12h. The gastrointestinal retention time of the new dosage form was indirectly estimated by determining the duration of riboflavin excretion after oral intake of the tablet. A crossover in vivo study with 12 healthy male and female subjects was performed. The renal excretion of riboflavin was measured after oral administration of collagen tablets and small sustained release hydrocolloid tablets as reference preparation. The amount of riboflavin excreted into the urine was enhanced after administration of the expanding collagen tablets in comparison with the hydrocolloid tablets. The differences were statistically significant after 5, 6, 8, 9, 10 and 12 h.
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Affiliation(s)
- Rüdiger Gröning
- Institute of Pharmaceutical Technology and Biopharmaceutics, Westphalien Wilhelms-University, Corrensstr. 1, D-48149 Münster, Germany.
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9
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Abstract
A controlled drug delivery system with prolonged residence time in the stomach is of particular interest for drugs that i) are locally active in the stomach, ii) have an absorption window in the stomach or in the upper small intestine, iii) are unstable in the intestinal or colonic environment, or iv) exhibit low solubility at high pH values. This article gives an overview of the parameters affecting gastric emptying in humans as well as on the main concepts used to design pharmaceutical dosage forms with prolonged gastric residence times. In particular, bioadhesive, size-increasing and floating drug delivery systems are presented and their major advantages and shortcomings are discussed. Both single- and multiple-unit dosage forms are reviewed and, if available, results from in vivo trials are reported.
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Affiliation(s)
- Alexander Streubel
- College of Pharmacy, Freie Universität Berlin, Kelchstr. 31, 12169 Berlin, Germany.
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10
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Abstract
Various attempts have been made to develop gastroretentive delivery systems. For example, floating, swelling, mucoadhesive, and high-density systems have been developed to increase gastric retention time of the dosage forms. It is known that differences in gastric physiology, such as, gastric pH, and motility exhibit both intra- as well as inter-subject variability demonstrating significant impact on gastric retention time and drug delivery behavior. Nevertheless, some floating devices have shown promising results. In this paper, the gastric physiology and the reported intragastric delivery systems have briefly been presented.
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Affiliation(s)
- R Talukder
- Temple University School of Pharmacy, Philadelphia, PA 19140, USA
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11
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Abstract
Expandable gastroretentive dosage forms (GRDFs) have been designed for the past 3 decades. They were originally created for possible veterinary use, but later the design was modified for enhanced drug therapy in humans. These GRDFs are easily swallowed and reach a significantly larger size in the stomach due to swelling or unfolding processes that prolong their gastric retention time (GRT). After drug release, their dimensions are minimized with subsequent evacuation from the stomach. Gastroretentivity is enhanced by the combination of substantial dimensions with high rigidity of the dosage form to withstand the peristalsis and mechanical contractility of the stomach. Positive results were obtained in preclinical and clinical studies evaluating GRT of expandable GRDFs. Narrow absorption window drugs compounded in such systems have improved in vivo absorption properties. These findings are an important step towards the implementation of expandable GRDFs in the clinical setting. The current review deals with expandable GRDFs reported in articles and patents, and describes the physiological basis of their design. Using the dog as a preclinical screening model prior to human studies, relevant imaging techniques and pharmacokinetic-pharmacodynamic aspects of such delivery systems are also discussed.
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Affiliation(s)
- Eytan A Klausner
- Department of Pharmaceutics, School of Pharmacy, Faculty of Medicine, The Hebrew University of Jerusalem POB 12065, Jerusalem 91120, Israel
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Einmahl S, Capancioni S, Schwach-Abdellaoui K, Moeller M, Behar-Cohen F, Gurny R. Therapeutic applications of viscous and injectable poly(ortho esters). Adv Drug Deliv Rev 2001; 53:45-73. [PMID: 11733117 DOI: 10.1016/s0169-409x(01)00220-4] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Poly(ortho esters) (POE) are hydrophobic and bioerodible polymers that have been investigated for pharmaceutical use since the early 1970s. Among the four described generations of POE, the third (POE III) and fourth (POE IV) are promising viscous and injectable materials which have been investigated in numerous biomedical applications. POE III has been extensively studied for ophthalmic drug delivery, it presents an excellent biocompatibility and is currently being investigated as a vehicle for sustained drug delivery to treat diseases of the posterior segment of the eye. POE IV is distinguishable by a highly reproducible and controlled synthesis, a higher hydrophobicity, and an excellent biocompatibility. It is currently under development for a variety of applications, such as ocular delivery, periodontal disease treatment and applications in veterinary medicine. This review will also focus on new perspectives for this promising family of polymers, such as guided tissue regeneration, treatment of osteoarthritis, as well as peptide and protein delivery.
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Affiliation(s)
- S Einmahl
- Department of Pharmaceutics and Biopharmaceutics, School of Pharmacy, University of Geneva, 30 quai Ernest-Ansermet, CH-1211 Geneva 4, Switzerland
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13
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Soppimath KS, Kulkarni AR, Rudzinski WE, Aminabhavi TM. Microspheres as floating drug-delivery systems to increase gastric retention of drugs. Drug Metab Rev 2001; 33:149-60. [PMID: 11495501 DOI: 10.1081/dmr-100104401] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Gastric emptying is a complex process, which is highly variable and makes in vivo performance of the drug-delivery systems uncertain. In order to avoid this variability, efforts have been made to increase the retention time of the drug-delivery systems for more than 12 h. The floating or hydrodynamically controlled drug-delivery systems are useful in such applications. The present review addresses briefly the physiology of the gastric emptying process with respect to floating drug-delivery systems. In recent years, the multiparticulate drug-delivery systems are used in the oral delivery of drugs. One of the approaches toward this goal is to develop the floating microspheres so as to increase the gastric retention time. Such systems have more advantages over the single-unit dosage forms. The development of floating microspheres involves different solvent evaporation techniques to create the hollow inner core. The present review addresses the preparation and characterization of the floating microspheres for the peroral route of administration of the drug.
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Affiliation(s)
- K S Soppimath
- Department of Chemistry, Karnatak University, Dharwad, India
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14
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Affiliation(s)
- S E Harding
- NCMH Unit, University of Nottingham, School of Biological Sciences, Sutton Bonington, Leics., UK
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15
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Abstract
A programmable, controlled release drug delivery system has been developed. The device in the form of a non-digestible oral capsule (containing drug in a slowly eroding matrix for controlled release) was designed to utilize an automatically operated geometric obstruction that keeps the device floating in the stomach and prevents it from passing through the remainder of the GIT. Different viscosity grades of hydroxypropyl-methyl-cellulose were employed as model eroding matrices. The duration during which the device could maintain its geometric obstruction (caused by a built-in triggering ballooning system) was dependent on the erosion rates of the incorporated polymers (the capsule in-hosed core matrix). After complete core matrix erosion, the ballooning system is automatically flattened off so that the device retains its normal capsule size to be eliminated by passing through the GIT. In vitro long-term drug delivery from a prototype model was studied using levonorgestril as a model drug. Zero-order release could be maintained for periods ranging between 5 and 20 days before the geometric obstruction is triggered off. The rate of drug release was dependent on the nature, viscosity and ratios of polymer employed.
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Affiliation(s)
- F M Sakr
- Department of Pharmaceutics, Faculty of Pharmacy, Mansoura University, Mansoura, Egypt
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16
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Leung SH, Irons BK, Robinson JR. Polyanionic hydrogel as a gastric retentive system. JOURNAL OF BIOMATERIALS SCIENCE. POLYMER EDITION 1993; 4:483-92. [PMID: 8241064 DOI: 10.1163/156856293x00140] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Gastric emptying of a polyanionic hydrogel, polycarbophil (PC), from the canine stomach was studied using a duodenal cannulation technique. The basis of the study is to employ a certain quantity of swelling hydrogel that, by virtue of its swollen size and viscosity, converts a fasted stomach to a fed state and resists discharge from the stomach for an extended period of time. Different amounts of PC, in 200 ml water plus buffering agents, were administered orally to fasted canines. The gastric emptying lag time was found to increase with the viscosity of the administered dose. Addition of a base, sodium bicarbonate, to PC increased gastric retention via an increase in its apparent viscosity. The polymer mass is retained in the canine stomach until a sufficient quantity of stomach acid secretion reduces the viscosity of the viscous mass, through protonation of polycarbophil, and, at that point, discharge of the hydrogel will commence. Thus, gastric retention of PC hydrogel in the canine stomach can be prolonged by increasing the apparent viscosity of the hydrogel administered.
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Affiliation(s)
- S H Leung
- Columbia Research Laboratories, Madison, WI 53713
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17
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Shalaby WS, Blevins WE, Park K. In vitro and in vivo studies of enzyme-digestible hydrogels for oral drug delivery. J Control Release 1992. [DOI: 10.1016/0168-3659(92)90071-x] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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18
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Shalaby WS, Blevins WE, Park K. Use of ultrasound imaging and fluoroscopic imaging to study gastric retention of enzyme-digestible hydrogels. Biomaterials 1992; 13:289-96. [PMID: 1600031 DOI: 10.1016/0142-9612(92)90052-p] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Ultrasound and fluoroscopic imaging techniques were used to monitor the gastric retention of enzyme-digestible hydrogels in the canine stomach. When water was present in the stomach, ultrasound imaging was very effective in monitoring the position of the hydrogel in the stomach, solvent penetration into the gel, and the gastric tissue-gel interactions during peristalsis. Rubbery or fully swollen hydrogels appeared as sonolucent objects with ultrasound imaging. Partially swollen hydrogels displayed a sonolucent outer layer due to solvent penetration and a centrally located bright echo resulting from the acoustic impedance mismatch at the glassy/rubbery interface. The degree of gastric tissue-gel interactions during peristalsis was inversely related to the extent of lumenal distention with water. The effectiveness of peristaltic contractions in driving the hydrogel toward the pyloric sphincter increased as the water was emptied from the stomach. In the absence of water, imaging of the gel with ultrasound became difficult. For this reason, gels were loaded with diatrizoate meglumine/sodium diatrizoate to visualize in real-time using fluoroscopic imaging. Fluoroscopic imaging allowed only indirect assessment of the hydrogel movement during peristalsis and the degree of hydrogel swelling. The gastric retention of the hydrogel under fasted conditions was influenced by the degree of gel deformation in response to peristaltic contractions. Hydrogels with a low degree of deformation during peristalsis showed long gastric retention times. The utilization of ultrasound imaging and fluoroscopic imaging for monitoring dynamic events in the stomach provided information on hydrogel properties which are important to gastric retention. The use of these imaging techniques in the development of long-term oral drug delivery systems is described.
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Affiliation(s)
- W S Shalaby
- Purdue University, School of Pharmacy, School of Veterinary Medicine, West Lafayette, Indiana 47907
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