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Feng J, Huang M, Chai Z, Li C, Huang W, Cui L, Li Y. The influence of oil composition on the transformation, bioaccessibility, and intestinal absorption of curcumin in nanostructured lipid carriers. Food Funct 2020; 11:5223-5239. [PMID: 32458895 DOI: 10.1039/d0fo00473a] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
In this study, the influences of liquid medium-chain triglyceride (MCT) and solid glyceryl tristearate (GTS) contents in the lipid matrix of nanostructured lipid carriers (NLCs) on their delivering capacities with respect to curcumin (Cur) were investigated by using a simulated gastrointestinal tract and Caco-2 monolayer models. The transformation of the encapsulated Cur decreased on increasing the MCT content in the lipid matrix of NLCs because it facilitated their lipolysis and promoted the exposure of Cur to a harsher exterior environment. Cur bioaccessibility was positively correlated with the level of micellized stearic acid resulting from GTS hydrolysis, which might be attributed to the fact that it could afford large hydrophobic domains to accommodate Cur. This value initially increased with an increase in the MCT content, reaching a maximum at 20% (w/w) and decreasing thereafter. The intestinal absorption of micellar Cur ranged from 26.06% to 38.76%, and a majority of the transported molecules were its reductive and conjugative metabolites. Overall, NLC containing 20% MCT in the lipid matrix afforded the highest Cur bioavailability, followed by that containing 10, 0, 40, 60, and 100% MCT. This work provides useful insights into the rational design of NLCs to optimize the bioavailability of the loaded agent.
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Affiliation(s)
- Jin Feng
- Institute of Agro-product Processing, Jiangsu Academy of Agricultural Sciences, 50 Zhongling Street, Nanjing 210014, China
| | - Meigui Huang
- Department of food science and engineering, College of light industry and food engineering, Nanjing forestry university, 159 Longpan Road, Nanjing 210037, China
| | - Zhi Chai
- Institute of Agro-product Processing, Jiangsu Academy of Agricultural Sciences, 50 Zhongling Street, Nanjing 210014, China
| | - Chunyang Li
- Institute of Agro-product Processing, Jiangsu Academy of Agricultural Sciences, 50 Zhongling Street, Nanjing 210014, China
| | - Wuyang Huang
- Institute of Agro-product Processing, Jiangsu Academy of Agricultural Sciences, 50 Zhongling Street, Nanjing 210014, China
| | - Li Cui
- Institute of Agro-product Processing, Jiangsu Academy of Agricultural Sciences, 50 Zhongling Street, Nanjing 210014, China
| | - Ying Li
- State Key Laboratory of Food Science and Technology, Jiangnan University, 1800 Lihu Road, Wuxi 214122, China. and Institute of Agro-product Processing, Jiangsu Academy of Agricultural Sciences, 50 Zhongling Street, Nanjing 210014, China
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2
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Spadarella G, Di Minno A, Donati MB, Mormile M, Ventre I, Di Minno G. From unfractionated heparin to pentasaccharide: Paradigm of rigorous science growing in the understanding of the in vivo thrombin generation. Blood Rev 2020; 39:100613. [DOI: 10.1016/j.blre.2019.100613] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2019] [Revised: 08/19/2019] [Accepted: 08/22/2019] [Indexed: 12/20/2022]
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3
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Shin M, Jang D, Nam H, Lee KH, Lee D. Predicting the Absorption Potential of Chemical Compounds Through a Deep Learning Approach. IEEE/ACM TRANSACTIONS ON COMPUTATIONAL BIOLOGY AND BIOINFORMATICS 2018; 15:432-440. [PMID: 26930688 DOI: 10.1109/tcbb.2016.2535233] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
The human colorectal carcinoma cell line (Caco-2) is a commonly used in-vitro test that predicts the absorption potential of orally administered drugs. In-silico prediction methods, based on the Caco-2 assay data, may increase the effectiveness of the high-throughput screening of new drug candidates. However, previously developed in-silico models that predict the Caco-2 cellular permeability of chemical compounds use handcrafted features that may be dataset-specific and induce over-fitting problems. Deep Neural Network (DNN) generates high-level features based on non-linear transformations for raw features, which provides high discriminant power and, therefore, creates a good generalized model. We present a DNN-based binary Caco-2 permeability classifier. Our model was constructed based on 663 chemical compounds with in-vitro Caco-2 apparent permeability data. Two hundred nine molecular descriptors are used for generating the high-level features during DNN model generation. Dropout regularization is applied to solve the over-fitting problem and the non-linear activation. The Rectified Linear Unit (ReLU) is adopted to reduce the vanishing gradient problem. The results demonstrate that the high-level features generated by the DNN are more robust than handcrafted features for predicting the cellular permeability of structurally diverse chemical compounds in Caco-2 cell lines.
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4
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Cheloha RW, Chen B, Kumar NN, Watanabe T, Thorne RG, Li L, Gardella TJ, Gellman SH. Development of Potent, Protease-Resistant Agonists of the Parathyroid Hormone Receptor with Broad β Residue Distribution. J Med Chem 2017; 60:8816-8833. [PMID: 29064243 DOI: 10.1021/acs.jmedchem.7b00876] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
The parathyroid hormone receptor 1 (PTHR1) is a member of the B-family of GPCRs; these receptors are activated by long polypeptide hormones and constitute targets of drug development efforts. Parathyroid hormone (PTH, 84 residues) and PTH-related protein (PTHrP, 141 residues) are natural agonists of PTHR1, and an N-terminal fragment of PTH, PTH(1-34), is used clinically to treat osteoporosis. Conventional peptides in the 20-40-mer length range are rapidly degraded by proteases, which may limit their biomedical utility. We have used the PTHR1-ligand system to explore the impact of broadly distributed replacement of α-amino acid residues with β-amino acid residues on susceptibility to proteolysis and agonist activity. This effort led us to identify new PTHR1 agonists that contain α → β replacements throughout their sequences, manifest potent agonist activity in cellular assays, and display remarkable resistance to proteolysis, in cases remaining active after extended exposure to simulated gastric fluid. The strategy we have employed suggests a path toward identifying protease-resistant agonists of other B-family GPCRs.
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Affiliation(s)
- Ross W Cheloha
- Department of Chemistry, University of Wisconsin-Madison , 1101 University Avenue, Madison, Wisconsin 53706, United States
| | - Bingming Chen
- School of Pharmacy, University of Wisconsin-Madison , 777 Highland Avenue, Madison, Wisconsin 53705, United States
| | - Niyanta N Kumar
- School of Pharmacy, University of Wisconsin-Madison , 777 Highland Avenue, Madison, Wisconsin 53705, United States
| | - Tomoyuki Watanabe
- Endocrine Unit, Massachusetts General Hospital and Harvard Medical School , Boston, Massachusetts 02114, United States
| | - Robert G Thorne
- School of Pharmacy, University of Wisconsin-Madison , 777 Highland Avenue, Madison, Wisconsin 53705, United States.,Clinical Neuroengineering Training Program, University of Wisconsin-Madison Biomedical Engineering , Engineering Centers Building, Room 2120, 1550 Engineering Drive, Madison Wisconsin 53706, United States.,Neuroscience Training Program & Center for Neuroscience, Wisconsin Institutes for Medical Research II , Rooms 9531 and 9533, 1111 Highland Avenue, Madison, Wisconsin 53705, United States.,Cellular and Molecular Pathology Graduate Training Program, UW Department of Pathology and Laboratory Medicine, University of Wisconsin-Madison , 1685 Highland Avenue, Madison, Wisconsin 53705, United States
| | - Lingjun Li
- Department of Chemistry, University of Wisconsin-Madison , 1101 University Avenue, Madison, Wisconsin 53706, United States.,School of Pharmacy, University of Wisconsin-Madison , 777 Highland Avenue, Madison, Wisconsin 53705, United States
| | - Thomas J Gardella
- Endocrine Unit, Massachusetts General Hospital and Harvard Medical School , Boston, Massachusetts 02114, United States
| | - Samuel H Gellman
- Department of Chemistry, University of Wisconsin-Madison , 1101 University Avenue, Madison, Wisconsin 53706, United States
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5
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Maher S, Mrsny RJ, Brayden DJ. Intestinal permeation enhancers for oral peptide delivery. Adv Drug Deliv Rev 2016; 106:277-319. [PMID: 27320643 DOI: 10.1016/j.addr.2016.06.005] [Citation(s) in RCA: 218] [Impact Index Per Article: 27.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2016] [Revised: 06/07/2016] [Accepted: 06/09/2016] [Indexed: 12/15/2022]
Abstract
Intestinal permeation enhancers (PEs) are one of the most widely tested strategies to improve oral delivery of therapeutic peptides. This article assesses the intestinal permeation enhancement action of over 250 PEs that have been tested in intestinal delivery models. In depth analysis of pre-clinical data is presented for PEs as components of proprietary delivery systems that have progressed to clinical trials. Given the importance of co-presentation of sufficiently high concentrations of PE and peptide at the small intestinal epithelium, there is an emphasis on studies where PEs have been formulated with poorly permeable molecules in solid dosage forms and lipoidal dispersions.
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He D, Ma J, Shi X, Zhao C, Hou M, Guo Q, Ma S, Li X, Zhao P, Liu W, Yang Z, Mou J, Song P, Zhang Y, Li J. Design, Synthesis, and Potent Antiepileptic Activity with Latent Nerve Rehabilitation of Novel γ-Aminobutyric Acid Derivatives. Chem Pharm Bull (Tokyo) 2014; 62:967-78. [DOI: 10.1248/cpb.c14-00329] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Affiliation(s)
- Dian He
- Institute of Medicinal Chemistry, School of Pharmaceutical Science, Lanzhou University
- State Key Laboratory of Applied Organic Chemistry, Lanzhou University
| | - Jing Ma
- Institute of Medicinal Chemistry, School of Pharmaceutical Science, Lanzhou University
| | - Xiuxiao Shi
- Institute of Medicinal Chemistry, School of Pharmaceutical Science, Lanzhou University
| | - Chunyan Zhao
- Institute of Medicinal Chemistry, School of Pharmaceutical Science, Lanzhou University
| | - Meng Hou
- Institute of Medicinal Chemistry, School of Pharmaceutical Science, Lanzhou University
| | - Qingxin Guo
- Institute of Medicinal Chemistry, School of Pharmaceutical Science, Lanzhou University
| | - Shangxian Ma
- Institute of Medicinal Chemistry, School of Pharmaceutical Science, Lanzhou University
| | - Xiaojun Li
- Institute of Medicinal Chemistry, School of Pharmaceutical Science, Lanzhou University
| | - Peicheng Zhao
- Institute of Medicinal Chemistry, School of Pharmaceutical Science, Lanzhou University
| | - Wenhu Liu
- Institute of Medicinal Chemistry, School of Pharmaceutical Science, Lanzhou University
| | - Zhuqing Yang
- Institute of Medicinal Chemistry, School of Pharmaceutical Science, Lanzhou University
| | - Jianping Mou
- Institute of Medicinal Chemistry, School of Pharmaceutical Science, Lanzhou University
| | - Pengfei Song
- Institute of Medicinal Chemistry, School of Pharmaceutical Science, Lanzhou University
| | - Yang Zhang
- Institute of Medicinal Chemistry, School of Pharmaceutical Science, Lanzhou University
| | - Jing Li
- Institute of Medicinal Chemistry, School of Pharmaceutical Science, Lanzhou University
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Paliwal R, Paliwal SR, Agrawal GP, Vyas SP. Biomimetic Solid Lipid Nanoparticles for Oral Bioavailability Enhancement of Low Molecular Weight Heparin and Its Lipid Conjugates: In Vitro and in Vivo Evaluation. Mol Pharm 2011; 8:1314-21. [DOI: 10.1021/mp200109m] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Rishi Paliwal
- Drug Delivery Research Laboratory and ‡Pharmaceutics Research Laboratory, Department of Pharmaceutical Sciences, Dr. H. S. Gour Vishwavidyalaya, Sagar, M.P., India, 470003
| | - Shivani R. Paliwal
- Drug Delivery Research Laboratory and ‡Pharmaceutics Research Laboratory, Department of Pharmaceutical Sciences, Dr. H. S. Gour Vishwavidyalaya, Sagar, M.P., India, 470003
| | - Govind P. Agrawal
- Drug Delivery Research Laboratory and ‡Pharmaceutics Research Laboratory, Department of Pharmaceutical Sciences, Dr. H. S. Gour Vishwavidyalaya, Sagar, M.P., India, 470003
| | - Suresh P. Vyas
- Drug Delivery Research Laboratory and ‡Pharmaceutics Research Laboratory, Department of Pharmaceutical Sciences, Dr. H. S. Gour Vishwavidyalaya, Sagar, M.P., India, 470003
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8
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Paliwal R, Paliwal SR, Agrawal GP, Vyas SP. Recent advances in search of oral heparin therapeutics. Med Res Rev 2011; 32:388-409. [DOI: 10.1002/med.20217] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
| | | | | | - Suresh P. Vyas
- Drug Delivery Research Laboratory; Department of Pharmaceutical Sciences; Dr. H. S. Gour Vishwavidyalaya; Sagar M.P. 470003 India
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9
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Zander F, Finkelmann H. State of Order of the Crosslinker in Main-Chain Liquid Crystalline Elastomers. MACROMOL CHEM PHYS 2010. [DOI: 10.1002/macp.200900659] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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10
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Alani AWG, Robinson JR. Mechanistic Understanding of Oral Drug Absorption Enhancement of Cromolyn Sodium by an Amino Acid Derivative. Pharm Res 2007; 25:48-54. [PMID: 17846867 DOI: 10.1007/s11095-007-9438-6] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2007] [Accepted: 08/13/2007] [Indexed: 10/22/2022]
Abstract
PURPOSE Examine the oral absorption enhancement mechanism of cromolyn sodium by sodium N-[8-(2-hydroxybenzoyl) amino] caprylate (SNAC) by evaluating the effect of SNAC on cromolyn sodium lipophilicity and changes in Caco-2 cell membrane fluidity. MATERIALS AND METHODS Standard Shake-flask method was used to evaluate the effect of SNAC on the lipophilicity of cromolyn sodium. The measurements were carried out in three partitioning solvents with varying hydrogen-bonding properties. Steady state fluorescence emission anisotropy technique was used to evaluate the effect of SNAC with/without cromolyn sodium on Caco-2 cell membrane fluidity. RESULTS The lipophilicity measurements showed that SNAC had no influence on the lipophilicity of cromolyn sodium in the three partitioning solvent systems. The findings of the steady-state fluorescence anisotropy showed that SNAC increases the membrane fluidity of the Caco-2 cells in a concentration dependent manner. The increase in fluidity with SNAC was seen in the presence and absence of cromolyn sodium and the presence of cromolyn sodium did not augment the effect of SNAC on membrane fluidity. CONCLUSIONS The increase in membrane fluidity by SNAC plays a pivotal role in the permeation enhancement mechanism of cromolyn sodium. Therefore, the increase in permeation is a result of changing Caco-2 cell membrane fluidity resulting in change in membrane integrity and not due to an increase in the lipophilicity of cromolyn sodium through its interaction with SNAC.
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Affiliation(s)
- Adam W G Alani
- School of Pharmacy, University of Wisconsin-Madison, Madison, WI 53705, USA,
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11
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Elsinghorst PW, Tanarro CMG, Gütschow M. Novel heterobivalent tacrine derivatives as cholinesterase inhibitors with notable selectivity toward butyrylcholinesterase. J Med Chem 2007; 49:7540-4. [PMID: 17149883 DOI: 10.1021/jm060742o] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Two series of novel heterobivalent tacrine derivatives were synthesized. A trimethoxy substituted benzene was linked to the tacrine moiety by a hydrazide-based linker. The compounds were evaluated as cholinesterase inhibitors, and trimethoxybenzoic acid derivatives with 11- or 12-atom spacers were the most potent inhibitors of human acetylcholinesterase. The inhibitors showed a surprising selectivity toward human butyrylcholinesterase, where several trimethoxyphenylpropionic acid derivatives had IC(50) values less than 250 pM.
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Affiliation(s)
- Paul W Elsinghorst
- Pharmazeutisches Institut, Rheinische Friedrich-Wilhelms-Universität Bonn, An der Immenburg 4, D-53121 Bonn, Germany
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12
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Grabovac V, Bernkop-Schnürch A. Improvement of the intestinal membrane permeability of low molecular weight heparin by complexation with stem bromelain. Int J Pharm 2006; 326:153-9. [PMID: 16950580 DOI: 10.1016/j.ijpharm.2006.06.042] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2006] [Revised: 06/27/2006] [Accepted: 06/28/2006] [Indexed: 11/19/2022]
Abstract
The aim of this study was to investigate the influence of the proteolytic enzyme bromelain on the permeation of heparin across the gastrointestinal epithelial barrier. Stability of the complex and effect of heparin on the enzymatic activity of bromelain was analysed photometrically by measuring bromelain enzymatic activity in complex with the heparin. In vitro permeation studies were performed with Caco-2 cell monolayer and rat small intestinal mucosa in Ussing-type chambers, respectively. Results revealed that enzymatic activity of bromelain remained uninfluenced by the immobilization of heparin on it. Transport studies across Caco-2 cell monolayer and rat small intestine showed that the permeation of heparin could be significantly increased in presence of bromelain. In the study with Caco-2 cells, the most effective molar ratio of bromelain to heparin was 2:1, leading to 6.7-fold improvement in uptake, whereas the molar ratio 1:1 showed the highest permeation enhancing effect in the study on intestinal mucosa. This study provides evidence that heparin and bromelain form stable complexes leading to a significantly improved uptake of heparin.
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Affiliation(s)
- V Grabovac
- Institute of Pharmacy, Department of Pharmaceutical Technology, University of Innsbruck, Innrain 52, 6020 Innsbruck, Austria
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13
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Ito Y, Kusawake T, Prasad YVR, Sugioka N, Shibata N, Takada K. Preparation and evaluation of oral solid heparin using emulsifier and adsorbent for in vitro and in vivo studies. Int J Pharm 2006; 317:114-9. [PMID: 16631328 DOI: 10.1016/j.ijpharm.2006.02.056] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2005] [Revised: 02/22/2006] [Accepted: 02/24/2006] [Indexed: 11/16/2022]
Abstract
Oral anticoagulant therapy with heparin has been challenged by formulating heparin in oral solid preparation. As heparin, low molecular weight heparin (LMWH) was used. LMWH was dispersed with a surfactant used for the self-microemulsifying drug delivery system (SMEDDS), PEG-8 caprylic/capric glycerides (Labrasol), and the mixture was solidified with three kinds of adsorbents, microporous calcium silicate (Florite RE), magnesium alminometa silicate (Neusilin US(2)) and silicon dioxide (Sylysia 320). The in vitro release study showed that the T50%s were 3.2+/-0.1min for Sylysia 320, 4.6+/-0.2min for Florite RE, 13.7+/-0.1min for Neusilin US(2). The in vivo rat absorption study showed that Florite RE system had the highest C(max), 0.42+/-0.01IU/mL and AUC, 0.59+/-0.06IUh/mL, where plasma LMWH levels were measured as anti-Xa activity. Other preparations had the C(max) and AUC, 0.12+/-0.01IU/mL and 0.15+/-0.02IUh/mL for Neusilin US(2) and 0.25+/-0.02IU/mL and 0.40+/-0.03IUh/mL for Sylysia 320, respectively. The bioavailability (BA) of LMWH from the microporous calcium silicate preparation, Florite RE, was 18.8% in rats by comparing the AUC obtained after i.v. injection of LMWH, 40IU/kg to another group of rats. Florite RE system was evaluated in dogs after oral administration in an enteric capsule made of Eudragit S100 at the LMWH dose of 200IU/kg. High plasma anti-Xa activity levels were obtained, i.e., the C(max) was 0.48+/-0.11IU/mL and AUC was 1.64+/-0.32IUh/mL. These results suggest that adsorbent system is useful as an oral solid delivery system of poorly absorbable drugs such as LMWH.
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Affiliation(s)
- Yukako Ito
- Department of Pharmacokinetics, Kyoto Pharmaceutical University, Yamashina-ku, Kyoto 607-8414, Japan.
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14
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Raitio KH, Savinainen JR, Vepsäläinen J, Laitinen JT, Poso A, Järvinen T, Nevalainen T. Synthesis and SAR Studies of 2-Oxoquinoline Derivatives as CB2 Receptor Inverse Agonists. J Med Chem 2006; 49:2022-7. [PMID: 16539390 DOI: 10.1021/jm050879z] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The highly CB2 selective cannabinoid receptor inverse agonist, 7-methoxy-2-oxo-8-pentyloxy-1,2-dihydroquinoline-3-carboxylic acid N-benzo[1,3]dioxol-5-ylmethyl)amide (JTE-907; 9b), served as the lead compound for investigating the structure-activity relationships of its analogues and in the search for more potent and effective CB2 receptor inverse agonists. A series of aromatic amides of 7-methoxy-2-oxo-8-pentyloxy-1,2-dihydroquinoline-3-carboxylic acid 6 was synthesized, and the CB2 receptor activities of the compounds were determined by a [35S]GTPgammaS-binding assay using membranes of CHO cells stably transfected with the human CB2 receptor. As a result, all the compounds were defined as full CB2 receptor inverse agonists, and additionally, except for two 3,4-dihydroxyphenylalkylamides, they were found to be equally potent as SR144528.
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Affiliation(s)
- Katri H Raitio
- Department of Pharmaceutical Chemistry, University of Kuopio, P.O. Box 1627, FI-70211 Kuopio, Finland.
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15
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MOTLEKAR NUSRATA, SRIVENUGOPAL KALKUNTES, WACHTEL MITCHELLS, YOUAN BIBOTTIC. Oral delivery of low-molecular-weight heparin using sodium caprate as absorption enhancer reaches therapeutic levels. J Drug Target 2006; 13:573-83. [PMID: 16390818 PMCID: PMC1993550 DOI: 10.1080/10611860500471906] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
The primary objective of this study was to evaluate sodium caprate as an oral penetration enhancer for low molecular weight heparin (LMWH), ardeparin. In vitro studies using Caco-2 cell monolayer indicated that 0.0625% of sodium caprate gave approximately 2-fold enhancement of ardeparin compared to negative control with almost 100% cell survival as evaluated by MTT cytotoxicity assay. In vivo studies in rats with ardeparin (1,200 IU/kg) and sodium caprate (100 mg/kg) led to a relative bioavailability of 27% with plasma anti-factor Xa levels within the therapeutic range (>0.2 IU/ml). Moreover, under these conditions, histological examination provided evidence that there was no damage to the gastrointestinal wall. Regional permeability studies using rat intestine indicated the colon as the region of maximum permeation. These results suggest that, at the dose administered, sodium caprate acts as a relatively safe and efficient absorption enhancer in the quest for alternatives for the oral delivery of LMWH.
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Affiliation(s)
- NUSRAT A. MOTLEKAR
- Department of Pharmaceutical Sciences, School of Pharmacy,
Texas Tech University Health Sciences Center, Amarillo, Texas, USA, and
| | - KALKUNTE S. SRIVENUGOPAL
- Department of Pharmaceutical Sciences, School of Pharmacy,
Texas Tech University Health Sciences Center, Amarillo, Texas, USA, and
| | - MITCHELL S. WACHTEL
- Department of Pathology, Divisions of Anatomic Pathology and
Research, Texas Tech University Health Sciences Center, Lubbock, Texas,
USA
| | - BI-BOTTI C. YOUAN
- Department of Pharmaceutical Sciences, School of Pharmacy,
Texas Tech University Health Sciences Center, Amarillo, Texas, USA, and
- Correspondence: B. C. Youan, Texas Tech University Health Sciences
Center, 1300 Coulter Drive, Amarillo, Texas 79106, USA. Tel: 806 356 4015. Ext.
236. Fax: 806 354 4034. E-mail:
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16
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Hayes PY, Ross BP, Thomas BG, Toth I. Polycationic lipophilic-core dendrons as penetration enhancers for the oral administration of low molecular weight heparin. Bioorg Med Chem 2006; 14:143-52. [PMID: 16169233 DOI: 10.1016/j.bmc.2005.08.004] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2005] [Revised: 08/01/2005] [Accepted: 08/01/2005] [Indexed: 10/25/2022]
Abstract
Two polycationic lipophilic-core carbohydrate-based dendrons 2a-b and five polycationic lipophilic-core peptide dendrons 3-6, containing four arginine or lysine terminal residues, were synthesized and then tested in rats as penetration enhancers for the oral delivery of low molecular weight heparin. Better results were obtained with dendrons containing terminal lysine residues than terminal arginine. A significant anti-factor Xa activity was obtained when low molecular weight heparin was coadministered with dendron 5.
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Affiliation(s)
- Patricia Y Hayes
- Discipline of Chemistry, School of Molecular and Microbial Sciences, and School of Pharmacy, The University of Queensland, Brisbane, Queensland 4072, Australia
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17
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Hess S, Rotshild V, Hoffman A. Investigation of the enhancing mechanism of sodium N-[8-(2-hydroxybenzoyl)amino]caprylate effect on the intestinal permeability of polar molecules utilizing a voltage clamp method. Eur J Pharm Sci 2005; 25:307-12. [PMID: 15911227 DOI: 10.1016/j.ejps.2005.03.003] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2004] [Accepted: 03/08/2005] [Indexed: 10/25/2022]
Abstract
Oral administration of sodium N-[8-(2-hydroxybenzoyl)amino]caprylate (SNAC) has been reported to increase the bioavailability of various macromolecules. The present study was aimed to study the effect of SNAC on the intestinal tissue permeability of polar charged molecules, using 6-carboxy-fluorescein (6-CF) as a model. The effects of SNAC on rat intestinal permeability was investigated ex vivo by utilizing voltage clamp experiments in a side-by-side diffusion chamber model in comparison with the effect of EDTA (10mM). The intestinal permeability of 6-CF was increased two-fold in the presence of 33-66 mM SNAC, and by 6.5-fold in the presence of 10mM EDTA. The voltage clamp experiments show that the effect of SNAC was particularly on the transcellular 7-folds increase (that was five times larger than the paracellular transport of the model agent). While EDTA affected predominantly paracellular pathway transport, SNAC 33-66 mM had no effect on [(3)H]-mannitol transport or any toxic effect on tissue integrity measured by TEER values. In conclusion, this study demonstrates that SNAC can facilitate passive transport of polar charged molecules through the membrane of epithelial enterocytes. This is noteworthy in view of the very low tendency of a charged molecule to permeate across the lipophilic inter-phase of the enterocytes membrane.
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Affiliation(s)
- Shmuel Hess
- Department of Pharmaceutics, School of Pharmacy, Faculty of Medicine, The Hebrew University of Jerusalem, P.O. Box 12065, Jerusalem 91120, Israel
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18
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Schmitz T, Leitner VM, Bernkop-Schnürch A. Oral heparin delivery: Design and in vivo evaluation of a stomach-targeted mucoadhesive delivery system. J Pharm Sci 2005; 94:966-73. [PMID: 15793802 DOI: 10.1002/jps.20311] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Low molecular weight heparin (LMWH) is an agent of choice in the anti-coagulant therapy and prophylaxis of thrombosis and coronary syndromes. However, the therapeutic use is partially limited due to a poor oral bioavailability. It was therefore the aim of this study to design and evaluate a highly efficient stomach-targeted oral delivery system for LMWH. In order to appraise the influence of the molecular weight on the oral bioavailability, mini-tablets comprising 3 kDa (279 IU) and 6 kDa (300 IU) LMWH, respectively, were generated and tested in vivo in rats. The potential of the test formulations based on thiolated polycarbophil, was evaluated in comparison to hydroxyethylcellulose (HEC) as control carrier matrix. The plasma levels of LMWH after oral versus subcutaneous administration were determined in order to calculate the relative bioavailability. With the delivery system containing 3 kDa LMWH (279 IU) a relative bioavailability of 19.1% was achieved, offering a significantly (p < 0.05) better bioavailability than the control system displaying a relative bioavailability of 8.1% The 6 kDa LMWH (300 IU) formulation displayed a relative bioavailability of 10.7% in contrast to the control displaying a relative bioavailability of 2.1%. In conclusion, these results suggest that mucoadhesive thiolated polymers are a promising tool for the non-invasive stomach-targeted systemic delivery of LMWH as model for a hydrophilic macromolecular polysaccharide.
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Affiliation(s)
- Thierry Schmitz
- Department of Pharmaceutical Technology, Institute of Pharmacy, Leopold-Franzens-University Innsbruck, Innrain 52, 6020 Innsbruck, Austria
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Dong L, Yum A, Nguyen J, Wong P. Enhanced ileal absorption of a hydrophilic macromolecule, pentosan polysulfate sodium (PPS). JOURNAL OF BIOMATERIALS SCIENCE-POLYMER EDITION 2005; 15:671-82. [PMID: 15264667 DOI: 10.1163/156856204323046924] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
An in situ gelling, bioadhesive liquid formulation was developed to enhance the bioavailbility (BA) of a polysaccharide, pentosan polysulfate sodium (PPS). The formulation was tested to determine its bioavailability enhancement in a non-flush/non-ligated rat ileal model. A potent synergistic effect was found with a gelling agent Cremophor and a permeation enhancer sodium salicylate. The absolute bioavailabilities were 1.9%, 4.6%, 6.3% and 46.4%, respectively, for the PPS solution in saline, sodium salicylate/PPS, Cremophor/PPS and Cremophor/sodium salicylate/PPS. Therefore, we successfully demonstrated the approach of utilizing an in situ gelling/bioadhesive liquid carrier to enhancing the bioavailability of a hydrophilic macromolecule at the distal small intestine.
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Affiliation(s)
- Liang Dong
- ALZA Corporation, 1010 Joaquin Road, P.O. Box 7210, Mountain View, CA 94039-7210, USA.
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20
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Mori S, Matsuura A, Rama Prasad YV, Takada K. Studies on the Intestinal Absorption of Low Molecular Weight Heparin Using Saturated Fatty Acids and Their Derivatives as an Absorption Enhancer in Rats. Biol Pharm Bull 2004; 27:418-21. [PMID: 14993814 DOI: 10.1248/bpb.27.418] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Intestinal absorption of low molecular weight heparin (LMWH) as well as unfractionated heparin (UFH) is limited due to its large molecular size and extensive negative charge. Development of its oral formulations would allow outpatient treatment with LMWH and UFH, and contribute a reduction in hospital expenses. The present study was aimed at evaluating the absorption enhancers Labrasol and Gelucire 44/14, which mainly consist of glycerides and fatty acids esters, to improve the intestinal absorption of LMWH. The absorption effects of saturated fatty acids with several carbon chain lengths (C6-C14) were also investigated. LMWH formulated with or without absorption enhancer was administered to the duodenum of fasted rats. The doses of LMWH and absorption enhancer were 20 mg/kg and 30 mg/kg, respectively. Plasma anti-Xa activity was measured as a marker of the LMWH absorption. By administration of the LMWH formulation with Labrasol but not with Gelucire 44/14, the plasma anti-Xa activity was increased to a level above 0.2 IU/ml which is the critical level for elucidation of its anticoagulant activity. Saturated fatty acids also enhanced the intestinal absorption of LMWH, and the order of absorption-enhancing effect was C10=C12>C14>C16>C8> or =C6. These results suggest that the intestinal absorption of LMWH varies with carbon chain lengths of the saturated fatty acids.
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Affiliation(s)
- Saori Mori
- Shimizu Research Center, Shimizu Pharmaceutical Co., Ltd., Shimizu Miyakami, Shizuoka, Japan.
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21
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Cho SY, Sim JS, Kang SS, Jeong CS, Linhardt RJ, Kim YS. Enhancement of heparin and heparin disaccharide absorption by thePhytolacca americana saponins. Arch Pharm Res 2003; 26:1102-8. [PMID: 14723347 DOI: 10.1007/bf02994765] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
We studied the effects of phytolaccosides, saponins from Phytolacca americana, on the intestinal absorption of heparin in vitro and in vivo. The absorption enhancing activity of these compounds (phytolaccosides B, D2, E, F, G and I) was determined by changes in transepithelial electrical resistance (TEER) and the transport amount of heparin disaccharide, the major repeating unit of heparin, across Caco-2 cell monolayers. With the exception of phytolaccoside G, all of them decreased TEER values and increased the permeability in a dose-dependent and time-dependent manner. In vitro, phytolaccosides B, D2, and E showed significant absorption enhancing activities, while effects by phytolaccoside F and I were mild. In vivo, phytolaccoside E increased the activated partial thromboplastin time (APTT) and thrombin time, indicating that phytolaccoside E modulated the transport of heparin in intestinal route. Our results suggest that a series of phytolaccosides from Phytolacca americana can be applied as pharmaceutical excipients to improve the permeability of macromolecules and hydrophilic drugs having difficulty in absorption across the intestinal epithelium.
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Affiliation(s)
- So Yean Cho
- Natural Products Research Institute, College of Pharmacy Seoul National University, Seoul 110-460, Korea
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22
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Kast CE, Guggi D, Langoth N, Bernkop-Schnürch A. Development and in vivo evaluation of an oral delivery system for low molecular weight heparin based on thiolated polycarbophil. Pharm Res 2003; 20:931-6. [PMID: 12817900 DOI: 10.1023/a:1023803706746] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
PURPOSE It was the purpose of this study to develop a new oral drug delivery system for low molecular weight heparin (LMWH) providing an improved bioavailability and a prolonged therapeutic effect. METHODS The permeation enhancing polycarbophil-cysteine conjugate (PCP-Cys) used in this study displayed 111.4 +/- 6.4 microM thiol groups per gram polymer. Permeation studies on freshly excised intestinal mucosa were performed in Ussing chambers demonstrating a 2-fold improved uptake of heparin as a result of the addition of 0.5% (w/v) PCP-Cys and the permeation mediator glutathione (GSH). RESULTS Tablets containing PCP-Cys, GSH, and 279 IU of LMWH showed a sustained drug release over 4 h. To guarantee the swelling of the polymeric carrier matrix in the small intestine tablets were enteric coated. They were orally given to rats. For tablets being based on the thiomer/GSH system an absolute bioavailability of 19.9 +/- 9.3% (means +/- SD; n = 5) vs. intravenous injection could be achieved. whereas tablets comprising unmodified PCP did not lead to a significant (p < 0.01) heparin concentration in plasma. The permeation enhancing effect and subsequently a therapeutic heparin level was maintained for 24 h after a single dose. CONCLUSIONS Because of the strong and prolonged lasting permeation enhancing effect of the thiomer/GSH system, the oral bioavailability of LMWH could be significantly improved. This new delivery system represents therefore a promising tool for the oral administration of heparin.
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Affiliation(s)
- Constantia E Kast
- Center of Pharmacy Institute of Pharmaceutical Technology and Biopharmaceutics, University of Vienna, Althanstrasse 14, A-1090 Vienna, Austria
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Desamero RZB, Cheng H, Cahill S, Girvin M, Deng H, Callender R, Rath P, Variano B, Smart JE. Physical properties of compounds promoting oral delivery of macromolecular drugs. Biopolymers 2002; 67:26-40. [PMID: 11842411 DOI: 10.1002/bip.10039] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The spectroscopic and solution properties of a series of amidated acids (delivery agents), which promote the gastrointestinal absorption of USP heparin and other drugs that show poor oral bioavailability, are investigated using Raman and NMR spectroscopy. The results show evidence for self-association at low concentrations of delivery agents that increases as the concentration of the delivery agent is increased. The self-associate is characterized by ring-ring stacking interactions, and the best geometrical arrangement for the stacking is the parallel-shifted arrangement of the rings. In addition, the amide group participates in the formation of intermolecular hydrogen bonds in the self-associate. Unlike the rigid ring, the tails of these delivery agents remain relatively flexible in the self-associate. It is suggested that the limited solubility of the delivery agents at physiological pH arises from a percentage of protonated carboxyls. Their presence promotes the formation of intermolecular hydrophobic and ring stacking interactions, which are otherwise weakened by an ionized carboxyl group.
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Affiliation(s)
- Ruel Z B Desamero
- Department of Physics, City College of New York, New York, New York 10031, USA
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Desamero RZB, Cheng H, Cahill S, Girvin M, Deng H, Callender R, Rath P, Variano B, Smart JE. Interactions of amidated acids with heparin. Biopolymers 2002; 67:41-8. [PMID: 11842412 DOI: 10.1002/bip.10040] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Raman and NMR studies are performed to characterize the solution structures of complexes between heparin and a group of amidated acids, which act as delivery agents that facilitate the gastrointestinal absorption of orally administered heparin. At concentrations typically employed for the oral drug delivery of heparin, the contact points between heparin complexed with the delivery agents include points near the OH groups of heparin. The results suggest that heparin interacts rather nonspecifically with the amidated acids as monomers and with self-associated complexes of the delivery agents. It is also found that the carboxyl groups of at least one of the bioactive delivery agents easily protonates when it forms complexes with itself or heparin. This attribute may be one reason why this class of compounds is effective in the oral delivery of heparin.
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Affiliation(s)
- Ruel Z B Desamero
- Department of Physics, City College of New York, New York, New York 10031, USA
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Abstract
The necessity and advantages of colon-specific drug delivery systems have been well recognized and documented. In the past, the primary approaches to obtain colon-specific delivery achieved limited success and included prodrugs, pH- and time-dependent systems, and microflora-activated systems. Precise colon drug delivery requires that the triggering mechanism in the delivery system only respond to the physiological conditions particular to the colon. Hence, continuous efforts have been focused on designing colon-specific delivery systems with improved site specificity and versatile drug release kinetics to accommodate different therapeutic needs. Among the systems developed most recently for colon-specific delivery, four systems were unique in terms of achieving in vivo site specificity, design rationale, and feasibility of the manufacturing process (pressure-controlled colon delivery capsules (PCDCs), CODES, colonic drug delivery system based on pectin and galactomannan coating, and Azo hydrogels). The focus of this review is to provide detailed descriptions of the four systems, in particular, and in vitro/in vivo evaluation of colon-specific drug delivery systems, in general.
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Affiliation(s)
- Libo Yang
- Yamanouchi Pharma Technologies, Inc., 1050 Arastradero Road, Palo Alto, CA 94304, USA.
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26
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Cho SY, Kim JS, Li H, Shim C, Linhardt RJ, Kim YS. Enhancement of paracellular transport of heparin disaccharide across Caco-2 cell monolayers. Arch Pharm Res 2002; 25:86-92. [PMID: 11885699 DOI: 10.1007/bf02975268] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The enhancement of paracellular transport of heparin disaccharide using several absorption enhancers across Caco-2 cell monolayers was tested. The cytotoxicity of these enhancers was also examined. The enhancing effects by Quillaja saponin, dipotassium glycyrrhizinate, 18beta-glycyrrhetinic acid, sodium caprate and taurine were determined by changes in transepithelial electrical resistance (TEER) and the amount of heparin disaccharide transported across Caco-2 cell monolayers. Among the absorption enhancers, 18beta-glycyrrhetinic acid and taurine decreased TEER and increased the permeability of heparin disaccharide in a dose-dependent and time-dependent manner with little or negligible cytotoxicity. Our results indicate that these absorption enhancers can widen the tight junction, which is a dominant paracellular absorption route of hydrophilic compounds. It is highly possible that these absorption enhancers can be applied as pharmaceutical excipients to improve the transport of macromolecules and hydrophilic drugs having difficulty in permeability across the intestinal epithelium.
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Affiliation(s)
- So Yean Cho
- Natural Products Research Institute, Seoul National University, Korea
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27
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Thanou M, Verhoef JC, Junginger HE. Oral drug absorption enhancement by chitosan and its derivatives. Adv Drug Deliv Rev 2001; 52:117-26. [PMID: 11718935 DOI: 10.1016/s0169-409x(01)00231-9] [Citation(s) in RCA: 464] [Impact Index Per Article: 20.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Chitosan is a non-toxic, biocompatible polymer that has found a number of applications in drug delivery including that of absorption enhancer of hydrophilic macromolecular drugs. Chitosan, when protonated (pH<6.5), is able to increase the paracellular permeability of peptide drugs across mucosal epithelia. Chitosan derivatives have been evaluated to overcome chitosan's limited solubility and effectiveness as absorption enhancer at neutral pH values such as those found in the intestinal tract. Trimethyl chitosan chloride (TMC) has been synthesized at different degrees of quaternization. This quaternized polymer forms complexes with anionic macromolecules and gels or solutions with cationic or neutral compounds in aqueous environments and neutral pH values. TMC has been shown to considerably increase the permeation and/or absorption of neutral and cationic peptide analogs across intestinal epithelia. The mechanism by which TMC enhances intestinal permeability is similar to that of protonated chitosan. It reversibly interacts with components of the tight junctions, leading to widening of the paracellular routes. Mono-carboxymethylated chitosan (MCC) is a polyampholytic polymer, able to form visco-elastic gels in aqueous environments or with anionic macromolecules at neutral pH values. MCC appears to be less potent compared to the quaternized derivative. Nevertheless, MCC was found to increase the permeation and absorption of low molecular weight heparin (LMWH; an anionic polysaccharide) across intestinal epithelia. Neither chitosan derivative provokes damage of the cell membrane, and therefore they do not alter the viability of intestinal epithelial cells.
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Affiliation(s)
- M Thanou
- Leiden/Amsterdam Center for Drug Research, Division of Pharmaceutical Technology, Leiden University, PO Box 9502, 2300RA Leiden, The Netherlands
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Leone-Bay A, Sato M, Paton D, Hunt AH, Sarubbi D, Carozza M, Chou J, McDonough J, Baughman RA. Oral delivery of biologically active parathyroid hormone. Pharm Res 2001; 18:964-70. [PMID: 11496956 DOI: 10.1023/a:1010936227570] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
PURPOSE Parathyroid hormone (PTH), the only drug known to stimulate bone formation. is a peptide therapeutic indicated in the treatment of osteoporosis. Unfortunately, PTH is only effective when dosed by injection because it has no oral bioavailability. Herein we report the oral absorption of PTH in rats and monkeys facilitated by the novel delivery agent, N-[8-(2-hydroxy-4-methoxy)bensoyl]amino caprylic acid (4-MOAC). METHODS 4-MOAC was selected from a group of 100 delivery agents based on in vitro chromotography studies and in vivo screening studies in rats. The PTH/4-MOAC combination was then tested in monkeys. The interaction of 4-MOAC and PTH was evaluated by nuclear magnetic resonance (NMR) spectroscopy. RESULTS Monkeys were administered an aqueous solution containing 4-MOAC and PTH and mean peak serum PTH concentrations of about 3000 pg/mL were obtained. The relative bioavailability of oral PTH was 2.1% relative to subcutaneous administration. The biological activity of the orally-delivered PTH was further evaluated in a rat model of osteoporosis. These studies showed that the bone formed following oral PTH/4-MOAC administration was comparable to that formed following PTH injections. The 4-MOAC mediated absorption of PTH is hypothesized to be the result of a noncovalent interaction between 4-MOAC and PTH. The preliminary evaluation of this interaction by NMR is described. CONCLUSIONS 4-MOAC facilitates the absorption of PTH following oral administration to both rats and monkeys. The orally-absorbed PTH is biologically active as demonstrated in a rat model of osteoporosis.
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Affiliation(s)
- A Leone-Bay
- Emisphere Technologies, Inc, Tarrytown, New York 10591, USA.
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29
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Thanou M, Verhoef JC, Verheijden JH, Junginger HE. Intestinal absorption of octreotide using trimethyl chitosan chloride: studies in pigs. Pharm Res 2001; 18:823-8. [PMID: 11474787 DOI: 10.1023/a:1011092613951] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
PURPOSE To investigate the enhancing effect of trimethyl chitosan chloride (TMC) on the enteral absorption of octreotide and to delineate the required doses of both TMC and peptide in vivo in juvenile pigs. METHODS Six female pigs (body weight, 25 kg) were operated to induce a stoma at the beginning of their jejunum and to insert an in-dwelling fistula for intrajejunal (IJ) administration of the formulations. A silicone cannula was inserted at the jugular vein for blood sampling. One week after surgery the pigs received IJ octreotide solution administrations with or without TMC at pH 7.4 or chitosan HCl at pH 5.5. For determining bioavailability (F) values, the pigs also received an octreotide solution intravenously (IV). Blood samples were taken from the cannulated jugular vein and subsequently analyzed by radioimmunoassay. RESULTS Intrajejunal administration of 10 mg octreotide without any polymer (control solution) resulted in F values of 1.7 +/- 1.1% (mean +/- SE). Chitosan HCl 1.5% (w/v) at pH 5.5 led to a 3-fold increase in F compared to the control (non-polymer containing) formulations. Co-administration of octreotide with 5 and 10% (w/v) TMC at pH 7.4 resulted in 7.7- and 14.5-fold increase of octreotide absorption, respectively (F of 13.9 +/- 1.3% and 24.8 +/- 1.8%). IJ administration of 5 mg octreotide solutions resulted in low F values of 0.5 +/- 0.6%, whereas co-administration with 5% (w/v) TMC increased the intestinal octreotide bioavailability to 8.2 +/- 1.5%. CONCLUSIONS Cationic polymers of the chitosan type are able to enhance the intestinal absorption of the peptide drug octreotide in pigs. In this respect, TMC at neutral pH values of 7.4 appears to be more potent than chitosan HCl at a weak acidic pH of 5.5.
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Affiliation(s)
- M Thanou
- Leiden/Amsterdam Center for Drug Research, Division of Pharmaceutical Technology, Leiden University, The Netherlands
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Thanou M, Nihot MT, Jansen M, Verhoef JC, Junginger HE. Mono-N-carboxymethyl chitosan (MCC), a polyampholytic chitosan derivative, enhances the intestinal absorption of low molecular weight heparin across intestinal epithelia in vitro and in vivo. J Pharm Sci 2001; 90:38-46. [PMID: 11064377 DOI: 10.1002/1520-6017(200101)90:1<38::aid-jps5>3.0.co;2-3] [Citation(s) in RCA: 137] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The synthesis and evaluation of mono-N-carboxymethyl chitosan (MCC) as an intestinal permeation enhancer for macromolecular therapeutics is presented. MCCs were synthesized from two different viscosity grade chitosans to yield both high and low viscosity grade products. These MCCs were tested on Caco-2 cells for their efficiency to decrease the transepithelial electrical resistance (TEER) and to increase the paracellular permeability of the anionic macromolecular anticoagulant low molecular weight heparin (LMWH). For in vivo studies, LMWH was administered intraduodenally with or without MCC to rats. Both types of experiments were performed at pH 7.4. Results show that both viscosity grade MCCs managed to significantly decrease the TEER of Caco-2 cell monolayers when they were applied apically at concentrations of 3-5% (w/v). Transport studies with Caco-2 cells revealed substantial increases of LMWH permeation in the presence of both viscosity grade MCCs compared with controls. In rats, 3% (w/v) low viscosity MCC significantly increased the intestinal absorption of LMWH, reaching the therapeutic anticoagulant blood levels of LMWH. Both in vitro and in vivo results indicate that the polyampholytic chitosan modification MCC is a suitable and functional polymer for the delivery and intestinal absorption of anionic macromolecular therapeutics like LMWH.
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Affiliation(s)
- M Thanou
- Leiden/Amsterdam Center for Drug Research, Division of Pharmaceutical Technology, Leiden University, P.O. Box 9502, 2300RA Leiden, The Netherlands
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Applications of immobilized stationary-phase liquid chromatography: a potential in vitro technique. PHARMACEUTICAL SCIENCE & TECHNOLOGY TODAY 2000; 3:406-416. [PMID: 11116200 DOI: 10.1016/s1461-5347(00)00315-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Immobilized artificial-membrane chromatography is a potential in vitro technique for determining lipophilicity and studying drug transport and membrane interactions. It is reproducible, efficient and simple. Several other and newer applications of immobilized stationary-phase liquid chromatography have been reported, including the purification of membrane proteins, the synthesis of biomolecules and the simultaneous determination of enzyme activity and enantioselectivity. This article describes the immobilized artificial-membrane concept and provides an overview of the applications, advantages and limitations, in general, of immobilized stationary-phase chromatography.
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Leone-Bay A, Freeman J, O'Toole D, Rosado-Gray C, Salo-Kostmayer S, Tai M, Mercogliano F, Baughman RA. Studies directed at the use of a parallel synthesis matrix to increase throughput in an in vivo assay. J Med Chem 2000; 43:3573-6. [PMID: 11000012 DOI: 10.1021/jm990416r] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Heparin is the anticoagulant of choice for hospitalized patients, but it is dosed only by injection because it is not absorbed following oral administration. We have discovered and prepared compounds (delivery agents) that facilitate the gastrointestinal absorption of heparin in rats, monkeys, and humans when given orally. We are currently developing a parallel synthesis approach to increase our delivery agent screening throughput in vivo. This approach has been used to produce micromolar quantities of compounds for testing in rats in a 5 x 5 parallel synthesis array. Using an amine benzoylation reaction sequence, 10 mixtures were prepared. These mixtures contained equal weight quantities of five N-substituted, non-alpha, amino acid delivery agents. Each of these mixtures was orally administered to rats in combination with heparin, and plasma clotting times (APTT) were measured to determine activity. Deconvolution of the data accurately identified the most active individual components. Independent synthesis of these compounds verified their activity. This parallel synthesis approach is an effective tool for the screening of oral heparin delivery agents and has increased screening throughput significantly.
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Affiliation(s)
- A Leone-Bay
- Emisphere Technologies, Inc., 765 Old Saw Mill River Road, Tarrytown, New York 10591, USA.
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Abstract
This review addresses the field of improving oral bioavailability through the use of excipients that increase intestinal membrane permeability. The critical issues to consider in evaluating these approaches are 1) the extent of bioavailability enhancement achieved, 2) the influence of formulation and physiological variables, 3) toxicity associated with permeation enhancement, and 4) the mechanism of permeation enhancement. The categories of permeation enhancers discussed are surfactants, fatty acids, medium chain glycerides, steroidal detergents, acyl carnitine and alkanoylcholines, N-acetylated alpha-amino acids and N-acetylated non-alpha-amino acids, and chitosans and other mucoadhesive polymers. Some of these approaches have been developed to the stage of initial clinical trials. Several seem to have potential to improve oral bioavailabilities of poorly absorbed compounds without causing significant intestinal damage. In addition, the possible use of excipients that inhibit secretory transport is reviewed.
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Affiliation(s)
- B J Aungst
- DuPont Pharmaceuticals Co., P. O. Box 80400, Wilmington, DE 19880-0400, USA.
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Abstract
Macromolecules comprise a growing group of new drugs with great clinical promise. To date, the therapeutic application of these drugs has been limited, because they are effective only when administered parenterally. Unfortunately, macromolecular drugs are not absorbed following nonparenteral dosing, because the mechanisms of the human body are designed to degrade and/or exclude them. To overcome the numerous obstacles to the noninvasive delivery of these drugs, various approaches are under investigation including the use of delivery agents to promote drug absorption. This review provides a summary of the novel approaches currently in progress in the areas of transdermal, transmucosal, and oral delivery of macromolecular drugs facilitated by delivery agents. We review our own novel work in this area in some detail, including the methods developed for the synthesis of the delivery agents, in vitro screening techniques developed to select compounds for in vivo testing, and the results of in vivo screening in both rats and primates, including preliminary safety and efficacy studies. Finally, the results of Phase I clinical studies showing the oral delivery of heparin are presented.
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Affiliation(s)
- A Leone-Bay
- Emisphere Technologies, Inc., Tarrytown, NY 10591, USA
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