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Larsen NW, Kostrikov S, Hansen MB, Hjørringgaard CU, Larsen NB, Andresen TL, Kristensen K. Interactions of oral permeation enhancers with lipid membranes in simulated intestinal environments. Int J Pharm 2024; 654:123957. [PMID: 38430950 DOI: 10.1016/j.ijpharm.2024.123957] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2023] [Revised: 02/17/2024] [Accepted: 02/28/2024] [Indexed: 03/05/2024]
Abstract
The oral bioavailability of therapeutic peptides is generally low. To increase peptide transport across the gastrointestinal barrier, permeation enhancers are often used. Despite their widespread use, mechanistic knowledge of permeation enhancers is limited. To address this, we here investigate the interactions of six commonly used permeation enhancers with lipid membranes in simulated intestinal environments. Specifically, we study the interactions of the permeation enhancers sodium caprate, dodecyl maltoside, sodium cholate, sodium dodecyl sulfate, melittin, and penetratin with epithelial cell-like model membranes. To mimic the molecular composition of the real intestinal environment, the experiments are performed with two peptide drugs, salmon calcitonin and desB30 insulin, in fasted-state simulated intestinal fluid. Besides providing a comparison of the membrane interactions of the studied permeation enhancers, our results demonstrate that peptide drugs as well as intestinal-fluid components may substantially change the membrane activity of permeation enhancers. This highlights the importance of testing permeation enhancement in realistic physiological environments and carefully choosing a permeation enhancer for each individual peptide drug.
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Affiliation(s)
- Nanna Wichmann Larsen
- DTU Health Tech, Department of Health Technology, Technical University of Denmark, 2800 Kgs. Lyngby, Denmark; Center for Intestinal Absorption and Transport of Biopharmaceuticals, Technical University of Denmark, 2800 Kgs. Lyngby, Denmark
| | - Serhii Kostrikov
- DTU Health Tech, Department of Health Technology, Technical University of Denmark, 2800 Kgs. Lyngby, Denmark; Center for Intestinal Absorption and Transport of Biopharmaceuticals, Technical University of Denmark, 2800 Kgs. Lyngby, Denmark
| | - Morten Borre Hansen
- DTU Health Tech, Department of Health Technology, Technical University of Denmark, 2800 Kgs. Lyngby, Denmark; Center for Intestinal Absorption and Transport of Biopharmaceuticals, Technical University of Denmark, 2800 Kgs. Lyngby, Denmark
| | - Claudia Ulrich Hjørringgaard
- DTU Health Tech, Department of Health Technology, Technical University of Denmark, 2800 Kgs. Lyngby, Denmark; Center for Intestinal Absorption and Transport of Biopharmaceuticals, Technical University of Denmark, 2800 Kgs. Lyngby, Denmark
| | - Niels Bent Larsen
- DTU Health Tech, Department of Health Technology, Technical University of Denmark, 2800 Kgs. Lyngby, Denmark; Center for Intestinal Absorption and Transport of Biopharmaceuticals, Technical University of Denmark, 2800 Kgs. Lyngby, Denmark
| | - Thomas Lars Andresen
- DTU Health Tech, Department of Health Technology, Technical University of Denmark, 2800 Kgs. Lyngby, Denmark; Center for Intestinal Absorption and Transport of Biopharmaceuticals, Technical University of Denmark, 2800 Kgs. Lyngby, Denmark.
| | - Kasper Kristensen
- DTU Health Tech, Department of Health Technology, Technical University of Denmark, 2800 Kgs. Lyngby, Denmark; Center for Intestinal Absorption and Transport of Biopharmaceuticals, Technical University of Denmark, 2800 Kgs. Lyngby, Denmark.
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Tran H, Aihara E, Mohammed FA, Qu H, Riley A, Su Y, Lai X, Huang S, Aburub A, Chen JJH, Vitale OH, Lao Y, Estwick S, Qi Z, ElSayed MEH. In Vivo Mechanism of Action of Sodium Caprate for Improving the Intestinal Absorption of a GLP1/GIP Coagonist Peptide. Mol Pharm 2023; 20:929-941. [PMID: 36592951 DOI: 10.1021/acs.molpharmaceut.2c00443] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Sodium caprate (C10) has been widely evaluated as an intestinal permeation enhancer for the oral delivery of macromolecules. However, the effect of C10 on the intestinal absorption of peptides with different physicochemical properties and its permeation-enhancing effect in vivo remains to be understood. Here, we evaluated the effects of C10 on intestinal absorption in rats with a glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GIP-GLP1) dual agonist peptide (LY) and semaglutide with different enzymatic stabilities and self-association behaviors as well as the oral exposure of the LY peptide in minipigs. Furthermore, we investigated the mechanism of action (MoA) of C10 for improving the intestinal absorption of the LY peptide in vivo via live imaging of the rat intestinal epithelium and tissue distribution of the LY peptide in minipigs. The LY peptide showed higher proteolytic stability in pancreatin and was a monomer in solution compared to that in semaglutide. C10 increased in vitro permeability in the minipig intestinal organoid monolayer to a greater extent for the LY peptide than for semaglutide. In the rat jejunal closed-loop model, C10 increased the absorption of LY peptide better than that of semaglutide, which might be attributed to higher in vitro proteolytic stability and permeability of the LY peptide. Using confocal live imaging, we observed that C10 enabled the rapid oral absorption of a model macromolecule (FD4) in the rat intestine. In the duodenum tissues of minipigs, C10 was found to qualitatively reduce the tight junction protein level and allow peptide uptake to the intestinal cells. C10 decreased the transition temperature of the artificial lipid membrane, indicating an increase in membrane fluidity, which is consistent with the above in vivo imaging results. These data indicated that the LY's favorable physicochemical properties combined with the effects of C10 on the intestinal mucosa resulted in an ∼2% relative bioavailability in minipigs.
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3
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Kim D, Jin L, Park EJ, Na DH. Peptide permeation enhancers for improving oral bioavailability of macromolecules. JOURNAL OF PHARMACEUTICAL INVESTIGATION 2022. [DOI: 10.1007/s40005-022-00609-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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Considerations in the developability of peptides for oral administration when formulated together with transient permeation enhancers. Int J Pharm 2022; 628:122238. [PMID: 36174850 DOI: 10.1016/j.ijpharm.2022.122238] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2022] [Revised: 09/10/2022] [Accepted: 09/22/2022] [Indexed: 11/22/2022]
Abstract
This paper reviews many of the properties of a peptide that need to be considered prior to development as an oral dosage form when co-formulated with a permeation enhancer to improve oral bioavailability, including the importance and implications of peptide half-life on variability in pharmacokinetic profiles. Clinical considerations in terms of food and drug-drug interactions are also discussed. The paper further gives a brief overview how permeation enhancers overcome barriers that limit oral absorption of peptides and thereby improve their oral bioavailability, albeit bioavailabilities are still low single digit and variability is high.
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Tran H, Patel PJ, Aburub A, Sperry A, Estwick S, ElSayed MEH, -Mannan AD. Identification of a Multi-Component Formulation for Intestinal Delivery of a GLP-1/Glucagon Co-agonist Peptide. Pharm Res 2022; 39:2555-2567. [PMID: 36050547 DOI: 10.1007/s11095-022-03372-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2022] [Accepted: 08/14/2022] [Indexed: 10/14/2022]
Abstract
PURPOSE Oral delivery of therapeutic peptides has been challenging due to multiple physiological factors and physicochemical properties of peptides. We report a systematic approach to identify formulation compositions combining a permeation enhancer and a peptidase inhibitor that minimize proteolytic degradation and increase absorption of a peptide across the small intestine. METHODS An acylated glucagon-like peptide-1/glucagon co-agonist peptide (4.5 kDa) was selected as a model peptide. Proteolytic stability of the peptide was investigated in rat and pig SIF. Effective PEs and multiple component formulations were identified in rats. Relative bioavailability of the peptide was determined in minipigs via intraduodenal administration (ID) of enteric capsules. RESULTS The peptide degraded rapidly in the rat and pig SIF. Citric acid, SBTI, and SBTCI inhibited the enzymatic degradation. The peptide self-associated into trimers in solution, however, addition of PEs monomerized the peptide. C10 was the most effective PE among tested PEs (DPC, LC, rhamnolipid, C12-maltosides, and SNAC) to improve intestinal absorption of the peptide in the rat IJ-closed loop model. A combination of C10 and SBTI or SBTCI increased the peptide exposure 5-tenfold compared to the exposure with the PE alone in the rat IJ-cannulated model, and achieved 1.06 ± 0.76% bioavailability in minipigs relative to subcutaneous via ID administration using enteric capsules. CONCLUSION We identified SBTI and C10 as an effective peptidase inhibitor and PE for intestinal absorption of the peptide. The combination of SBTI and C10 addressed the peptide physiochemical properties and provides a formulation strategy to achieve intestinal delivery of this peptide.
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Affiliation(s)
- Huyen Tran
- Biotechnology Discovery Research, Lilly Research Laboratories, Eli Lilly and Company, Lilly Corporate Center, Indianapolis, IN, 46285, USA.
| | - Phenil J Patel
- Synthetic Molecule Design and Development, Lilly Research Laboratories, Eli Lilly and Company, Lilly Corporate Center, Indianapolis, IN, 46285, USA
| | - Aktham Aburub
- Synthetic Molecule Design and Development, Lilly Research Laboratories, Eli Lilly and Company, Lilly Corporate Center, Indianapolis, IN, 46285, USA
| | - Andrea Sperry
- Department of Drug Disposition, Lilly Research Laboratories, Eli Lilly and Company, Lilly Corporate Center, Indianapolis, IN, 46285, USA
| | - Selina Estwick
- Department of Drug Disposition, Lilly Research Laboratories, Eli Lilly and Company, Lilly Corporate Center, Indianapolis, IN, 46285, USA
| | - Mohamed E H ElSayed
- Biotechnology Discovery Research, Lilly Research Laboratories, Eli Lilly and Company, Lilly Corporate Center, Indianapolis, IN, 46285, USA
| | - Amita Datta -Mannan
- Exploratory Medicine and Pharmacology, Lilly Research Laboratories, Eli Lilly and Company, Lilly Corporate Center, Indianapolis, IN, 46285, USA.
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6
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Klepach A, Tran H, Ahmad Mohammed F, ElSayed ME. Characterization and impact of peptide physicochemical properties on oral and subcutaneous delivery. Adv Drug Deliv Rev 2022; 186:114322. [PMID: 35526665 DOI: 10.1016/j.addr.2022.114322] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2021] [Revised: 02/21/2022] [Accepted: 05/02/2022] [Indexed: 11/25/2022]
Abstract
Peptides, an emerging modality within the biopharmaceutical industry, are often delivered subcutaneously with evolving prospects on oral delivery. Barrier biology within the subcutis or gastrointestinal tract is a significant challenge in limiting absorption or otherwise disrupting peptide disposition. Aspects of peptide pharmacokinetic performance and ADME can be mitigated with careful molecular design that tailors for properties such as effective size, hydrophobicity, net charge, proteolytic stability, and albumin binding. In this review, we endeavor to highlight effective techniques in qualifying physicochemical properties of peptides and discuss advancements of in vitro models of subcutaneous and oral delivery. Additionally, we will delineate empirical findings around the relationship of these physicochemical properties and in vivo (animal or human) impact. We conclude that robust peptide characterization methods and in vitro techniques with demonstrated correlations to in vivo data are key routines to incorporate in the drug discovery and development to improve the probability of technical and commercial success of peptide therapeutics.
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Berg S, Kärrberg L, Suljovic D, Seeliger F, Söderberg M, Perez-Alcazar M, Van Zuydam N, Abrahamsson B, Hugerth AM, Davies N, Bergström CAS. Impact of Intestinal Concentration and Colloidal Structure on the Permeation-Enhancing Efficiency of Sodium Caprate in the Rat. Mol Pharm 2022; 19:200-212. [PMID: 34928160 PMCID: PMC8728734 DOI: 10.1021/acs.molpharmaceut.1c00724] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
![]()
In this work, we
set out to better understand how the permeation
enhancer sodium caprate (C10) influences the intestinal absorption
of macromolecules. FITC-dextran 4000 (FD4) was selected as a model
compound and formulated with 50–300 mM C10. Absorption was
studied after bolus instillation of liquid formulation to the duodenum
of anesthetized rats and intravenously as a reference, whereafter
plasma samples were taken and analyzed for FD4 content. It was found
that the AUC and Cmax of FD4 increased
with increasing C10 concentration. Higher C10 concentrations were
associated with an increased and extended absorption but also increased
epithelial damage. Depending on the C10 concentration, the intestinal
epithelium showed significant recovery already at 60–120 min
after administration. At the highest studied C10 concentrations (100
and 300 mM), the absorption of FD4 was not affected by the colloidal
structures of C10, with similar absorption obtained when C10 was administered
as micelles (pH 8.5) and as vesicles (pH 6.5). In contrast, the FD4
absorption was lower when C10 was administered at 50 mM formulated
as micelles as compared to vesicles. Intestinal dilution of C10 and
FD4 revealed a trend of decreasing FD4 absorption with increasing
intestinal dilution. However, the effect was smaller than that of
altering the total administered C10 dose. Absorption was similar when
the formulations were prepared in simulated intestinal fluids containing
mixed micelles of bile salts and phospholipids and in simple buffer
solution. The findings in this study suggest that in order to optimally
enhance the absorption of macromolecules, high (≥100 mM) initial
intestinal C10 concentrations are likely needed and that both the
concentration and total dose of C10 are important parameters.
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Affiliation(s)
- Staffan Berg
- The Swedish Drug Delivery Center, Department of Pharmacy, Uppsala University, BMC P.O. Box 580, SE-751 23 Uppsala, Sweden.,Advanced Drug Delivery, Pharmaceutical Sciences, R&D, AstraZeneca, 431 83 Gothenburg, Sweden
| | - Lillevi Kärrberg
- Animal Sciences and Technologies, Clinical Pharmacology and Safety Sciences, Biopharmaceuticals R&D, AstraZeneca, 431 83 Gothenburg, Sweden
| | - Denny Suljovic
- The Swedish Drug Delivery Center, Department of Pharmacy, Uppsala University, BMC P.O. Box 580, SE-751 23 Uppsala, Sweden
| | - Frank Seeliger
- Cardiovascular, Renal and Metabolism Safety, Clinical Pharmacology & Safety Sciences, BioPharmaceuticals R&D, AstraZeneca, 431 83 Gothenburg, Sweden
| | - Magnus Söderberg
- Cardiovascular, Renal and Metabolism Safety, Clinical Pharmacology & Safety Sciences, BioPharmaceuticals R&D, AstraZeneca, 431 83 Gothenburg, Sweden
| | - Marta Perez-Alcazar
- Imaging and Data Analytics, Clinical Pharmacology and Safety Sciences, Biopharmaceuticals R&D, AstraZeneca, 431 83 Gothenburg, Sweden
| | - Natalie Van Zuydam
- Data Science and Quantitative Biology, Discovery Sciences, BioPharmaceuticals R&D, AstraZeneca, 431 83 Gothenburg, Sweden
| | - Bertil Abrahamsson
- Oral Product Development, Pharmaceutical Technology & Development, Operations, AstraZeneca, 431 83 Gothenburg, Sweden
| | - Andreas M Hugerth
- Ferring Pharmaceuticals A/S Global Pharmaceutical R&D, 2300 Copenhagen, Denmark
| | - Nigel Davies
- Advanced Drug Delivery, Pharmaceutical Sciences, R&D, AstraZeneca, 431 83 Gothenburg, Sweden
| | - Christel A S Bergström
- The Swedish Drug Delivery Center, Department of Pharmacy, Uppsala University, BMC P.O. Box 580, SE-751 23 Uppsala, Sweden
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Best practices in current models mimicking drug permeability in the gastrointestinal tract - an UNGAP review. Eur J Pharm Sci 2021; 170:106098. [PMID: 34954051 DOI: 10.1016/j.ejps.2021.106098] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Revised: 10/19/2021] [Accepted: 12/15/2021] [Indexed: 12/21/2022]
Abstract
The absorption of orally administered drug products is a complex, dynamic process, dependent on a range of biopharmaceutical properties; notably the aqueous solubility of a molecule, stability within the gastrointestinal tract (GIT) and permeability. From a regulatory perspective, the concept of high intestinal permeability is intrinsically linked to the fraction of the oral dose absorbed. The relationship between permeability and the extent of absorption means that experimental models of permeability have regularly been used as a surrogate measure to estimate the fraction absorbed. Accurate assessment of a molecule's intestinal permeability is of critical importance during the pharmaceutical development process of oral drug products, and the current review provides a critique of in vivo, in vitro and ex vivo approaches. The usefulness of in silico models to predict drug permeability is also discussed and an overview of solvent systems used in permeability assessments is provided. Studies of drug absorption in humans are an indirect indicator of intestinal permeability, but in vitro and ex vivo tools provide initial screening approaches are important tools for direct assessment of permeability in drug development. Continued refinement of the accuracy of in silico approaches and their validation with human in vivo data will facilitate more efficient characterisation of permeability earlier in the drug development process and will provide useful inputs for integrated, end-to-end absorption modelling.
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9
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Formulation strategies to improve the efficacy of intestinal permeation enhancers . Adv Drug Deliv Rev 2021; 177:113925. [PMID: 34418495 DOI: 10.1016/j.addr.2021.113925] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2021] [Revised: 07/28/2021] [Accepted: 08/09/2021] [Indexed: 02/06/2023]
Abstract
The use of chemical permeation enhancers (PEs) is the most widely tested approach to improve oral absorption of low permeability active agents, as represented by peptides. Several hundred PEs increase intestinal permeability in preclinical bioassays, yet few have progressed to clinical testing and, of those, only incremental increases in oral bioavailability (BA) have been observed. Still, average BA values of ~1% were sufficient for two recent FDA approvals of semaglutide and octreotide oral formulations. PEs are typically screened in static in vitro and ex-vivo models where co-presentation of active agent and PE in high concentrations allows the PE to alter barrier integrity with sufficient contact time to promote flux across the intestinal epithelium. The capacity to maintain high concentrations of co-presented agents at the epithelium is not reached by standard oral dosage forms in the upper GI tract in vivo due to dilution, interference from luminal components, fast intestinal transit, and possible absorption of the PE per se. The PE-based formulations that have been assessed in clinical trials in either immediate-release or enteric-coated solid dosage forms produce low and variable oral BA due to these uncontrollable physiological factors. For PEs to appreciably increase intestinal permeability from oral dosage forms in vivo, strategies must facilitate co-presentation of PE and active agent at the epithelium for a sustained period at the required concentrations. Focusing on peptides as examples of a macromolecule class, we review physiological impediments to optimal luminal presentation, discuss the efficacy of current PE-based oral dosage forms, and suggest strategies that might be used to improve them.
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Enhancing Intestinal Absorption of a Model Macromolecule via the Paracellular Pathway using E-Cadherin Peptides. J Pharm Sci 2020; 110:2139-2148. [PMID: 33359310 DOI: 10.1016/j.xphs.2020.12.018] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2020] [Revised: 12/14/2020] [Accepted: 12/16/2020] [Indexed: 12/17/2022]
Abstract
Membrane permeation enhancers have received significant attention in recent years for enabling the oral absorption of poorly permeable drug molecules. In this study, we investigated the ability of His-Ala-Val (HAV) and Ala-Asp-Thr (ADT) peptides derived from the extracellular-1 (EC1) domain of E-cadherin proteins to increase the paracellular permeation and intestinal bioavailability of the poorly permeable model macromolecule, fluorescein-isothiocyanate dextran with average molecular weight 4000 (FD4). The in vitro enzymatic stability of linear and cyclic E-cadherin peptides was characterized under simulated gastric and intestinal conditions, and the cyclic E-cadherin peptides, HAVN1 and ADTC5, which demonstrated excellent stability in vitro, were advanced to in vivo intestinal instillation studies and compared against the established surfactant membrane permeation enhancer, sodium caprate (C10). Cyclic HAVN1 and ADTC5 peptides increased FD4 bioavailability by 7.2- and 4.4-fold compared to control, respectively (not statistically significant). In contrast, C10 provided a statistically significant 10.7-fold relative bioavailability enhancement for FD4. Importantly, this study represents the first report of cyclic E-cadherin peptides as intestinal membrane permeation enhancers. The findings described herein demonstrate the potential of enzymatically stabilized cyclic E-cadherin peptides for increasing poorly permeable drug absorption via the oral route.
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11
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Comparison of the effects of the intestinal permeation enhancers, SNAC and sodium caprate (C 10): Isolated rat intestinal mucosae and sacs. Eur J Pharm Sci 2020; 158:105685. [PMID: 33359131 DOI: 10.1016/j.ejps.2020.105685] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2020] [Revised: 11/30/2020] [Accepted: 12/16/2020] [Indexed: 12/22/2022]
Abstract
SNAC and C10 are intestinal permeation enhancers (PEs) used in formulations of peptides for oral delivery in clinical trials. Our aims were to compare their: (i) mechanism of action in isolated rat intestinal mucosae mounted in Ussing chambers and in non-everted gut sacs, (ii) effects on mucosa integrity in those models and also in in situ intra-jejunal instillations and (iii) interactions with intestinal mucus. SNAC increased the apparent permeability coefficient (Papp) of the paracellular marker, FITC-dextran 4000 (FD4), across isolated rat gastric mucosae in concentration-dependent fashion, whereas C10 did not, while both reduced the transepithelial electrical resistance (TEER). In isolated jejunal and colonic mucosae, both agents increased the Papp of [14C]-mannitol and FD4 whereas C10 but not SNAC reduced TEER. 20 mM SNAC was required to achieve the efficacy of 10 mM C10 in jejunal and colonic mucosae. In isolated non-everted jejunal and colonics sacs, FD4 flux increases were observed in the presence of both PEs. Histology of mucosae revealed that both PEs induced minor epithelial damage to the mucosa at concentrations that increased fluxes. Jejunal tissue withstood epithelial damage in the following order: intra jejunal in situ instillations > jejunal sacs > isolated jejunal mucosae. Both PEs modulated viscoelastic properties of porcine jejunal mucus without altering rheological properties. In conclusion, SNAC and C10 are reasonably efficacious PEs in rat intestinal tissue with common overall mechanistic features. Their potency and toxic potential are low, in agreement with clinical trial data.
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12
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Ruiz-Picazo A, Lozoya-Agullo I, González-Álvarez I, Bermejo M, González-Álvarez M. Effect of excipients on oral absorption process according to the different gastrointestinal segments. Expert Opin Drug Deliv 2020; 18:1005-1024. [PMID: 32842776 DOI: 10.1080/17425247.2020.1813108] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
INTRODUCTION Excipients are necessary to develop oral dosage forms of any Active Pharmaceutical Ingredient (API). Traditionally, excipients have been considered inactive and inert substances, but, over the years, numerous studies have contradicted this belief. This review focuses on the effect of excipients on the physiological variables affecting oral absorption along the different segments of the gastrointestinal tract. The effect of excipients on the segmental absorption variables are illustrated with examples to help understand the complexity of predicting their in vivo effects. AREAS COVERED The effects of excipients on disintegration, solubility and dissolution, transit time, and absorption are analyzed in the context of the different gastrointestinal segments and the physiological factors affecting release and membrane permeation. The experimental techniques used to study excipient effects and their human predictive ability are reviewed. EXPERT OPINION The observed effects of excipient in oral absorption process have been characterized in the past, mainly in vitro (i.e. in dissolution studies, in vitro cell culture methods or in situ animal studies). Unfortunately, a clear link with their effects in vivo, i.e. their impact on Cmax or AUC, which need a mechanistic approach is still missing. The information compiled in this review leads to the conclusion that the effect of excipients in API oral absorption and bioavailability is undeniable and shows the need of implementing standardized and reproducible preclinical tools coupled with mechanistic and predictive physiological-based models to improve the current empirical retrospective approach.
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Affiliation(s)
- Alejandro Ruiz-Picazo
- Engineering: Pharmacokinetics and Pharmaceutical Technology Area, Miguel Hernandez University, Elche, Spain
| | - Isabel Lozoya-Agullo
- Engineering: Pharmacokinetics and Pharmaceutical Technology Area, Miguel Hernandez University, Elche, Spain
| | - Isabel González-Álvarez
- Engineering: Pharmacokinetics and Pharmaceutical Technology Area, Miguel Hernandez University, Elche, Spain
| | - Marival Bermejo
- Engineering: Pharmacokinetics and Pharmaceutical Technology Area, Miguel Hernandez University, Elche, Spain
| | - Marta González-Álvarez
- Engineering: Pharmacokinetics and Pharmaceutical Technology Area, Miguel Hernandez University, Elche, Spain
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13
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Maher S, Geoghegan C, Brayden DJ. Intestinal permeation enhancers to improve oral bioavailability of macromolecules: reasons for low efficacy in humans. Expert Opin Drug Deliv 2020; 18:273-300. [PMID: 32937089 DOI: 10.1080/17425247.2021.1825375] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
INTRODUCTION Intestinal permeation enhancers (PEs) are substances that transiently alter the intestinal epithelial barrier to facilitate permeation of macromolecules with low oral bioavailability (BA). While a number of PEs have progressed to clinical testing in conventional formulations with macromolecules, there has been only low single digit increases in oral BA, irrespective of whether the drug met primary or secondary clinical endpoints. AREAS COVERED This article considers the causes of sub-optimal BA of macromolecules from PE dosage forms and suggests approaches that may improve performance in humans. EXPERT OPINION Permeation enhancement is most effective when the PE is co-localized with the macromolecule at the epithelial surface. Conditions in the GI tract impede optimal co-localization. Novel delivery systems that limit dilution and spreading of the PE and macromolecule in the small intestine have attempted to replicate promising enhancement efficacy observed in static drug delivery models.
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Affiliation(s)
- Sam Maher
- School of Pharmacy, Royal College of Surgeons in Ireland, Dublin, Ireland
| | - Caroline Geoghegan
- School of Pharmacy, Royal College of Surgeons in Ireland, Dublin, Ireland
| | - David J Brayden
- UCD School of Veterinary Medicine and UCD Conway Institute, University College Dublin, Dublin, Ireland
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14
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Dahlgren D, Cano-Cebrián MJ, Olander T, Hedeland M, Sjöblom M, Lennernäs H. Regional Intestinal Drug Permeability and Effects of Permeation Enhancers in Rat. Pharmaceutics 2020; 12:pharmaceutics12030242. [PMID: 32182653 PMCID: PMC7150977 DOI: 10.3390/pharmaceutics12030242] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2020] [Revised: 02/26/2020] [Accepted: 03/03/2020] [Indexed: 12/25/2022] Open
Abstract
Sufficient colonic absorption is necessary for all systemically acting drugs in dosage forms that release the drug in the large intestine. Preclinically, colonic absorption is often investigated using the rat single-pass intestinal perfusion model. This model can determine intestinal permeability based on luminal drug disappearance, as well as the effect of permeation enhancers on drug permeability. However, it is uncertain how accurate the rat single-pass intestinal perfusion model predicts regional intestinal permeability and absorption in human. There is also a shortage of systematic in vivo investigations of the direct effect of permeation enhancers in the small and large intestine. In this rat single-pass intestinal perfusion study, the jejunal and colonic permeability of two low permeability drugs (atenolol and enalaprilat) and two high-permeability ones (ketoprofen and metoprolol) was determined based on plasma appearance. These values were compared to already available corresponding human data from a study conducted in our lab. The colonic effect of four permeation enhancers—sodium dodecyl sulfate, chitosan, ethylenediaminetetraacetic acid (EDTA), and caprate—on drug permeability and transport of chromium EDTA (an established clinical marker for intestinal barrier integrity) was determined. There was no difference in jejunal and colonic permeability determined from plasma appearance data of any of the four model drugs. This questions the validity of the rat single-pass intestinal perfusion model for predicting human regional intestinal permeability. It was also shown that the effect of permeation enhancers on drug permeability in the colon was similar to previously reported data from the rat jejunum, whereas the transport of chromium EDTA was significantly higher (p < 0.05) in the colon than in jejunum. Therefore, the use of permeation enhancers for increasing colonic drug permeability has greater risks than potential medical rewards, as indicated by the higher permeation of chromium EDTA compared to the drugs.
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Affiliation(s)
- David Dahlgren
- Department of Pharmacy, Division of Biopharmaceutics, Uppsala University, 752 36 Uppsala, Sweden; (D.D.); (T.O.)
| | - Maria-Jose Cano-Cebrián
- Department of Pharmacy and Pharmaceutical Technology and Parasitology, University of Valencia, 46010 València, Spain;
| | - Tobias Olander
- Department of Pharmacy, Division of Biopharmaceutics, Uppsala University, 752 36 Uppsala, Sweden; (D.D.); (T.O.)
| | - Mikael Hedeland
- Department of Medicinal Chemistry, Analytical Pharmaceutical Chemistry, Uppsala University, 752 36 Uppsala, Sweden;
- Department of Chemistry, Environment and Feed Hygiene, National Veterinary Institute (SVA), 751 89 Uppsala, Sweden
| | - Markus Sjöblom
- Department of Neuroscience, Division of Physiology, Uppsala University, 752 36 Uppsala, Sweden;
| | - Hans Lennernäs
- Department of Pharmacy, Division of Biopharmaceutics, Uppsala University, 752 36 Uppsala, Sweden; (D.D.); (T.O.)
- Correspondence:
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15
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Effects of surfactant-based permeation enhancers on mannitol permeability, histology, and electrogenic ion transport responses in excised rat colonic mucosae. Int J Pharm 2018; 539:11-22. [DOI: 10.1016/j.ijpharm.2018.01.008] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2017] [Revised: 12/21/2017] [Accepted: 01/02/2018] [Indexed: 12/16/2022]
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16
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Aguirre TAS, Teijeiro-Osorio D, Rosa M, Coulter IS, Alonso MJ, Brayden DJ. Current status of selected oral peptide technologies in advanced preclinical development and in clinical trials. Adv Drug Deliv Rev 2016; 106:223-241. [PMID: 26921819 DOI: 10.1016/j.addr.2016.02.004] [Citation(s) in RCA: 211] [Impact Index Per Article: 26.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2016] [Revised: 02/15/2016] [Accepted: 02/18/2016] [Indexed: 01/12/2023]
Abstract
The development of oral dosage forms that allows absorption of therapeutic peptides to the systemic circulation is one of the greatest challenges for the pharmaceutical industry. Currently, a number of technologies including either mixtures of penetration enhancers or protease inhibitors and/or nanotechnology-based products are under clinical development. Typically, these formulations are presented in the form of enteric-coated tablets or capsules. Systems undergoing preclinical investigation include further advances in nanotechnology, including intestinal microneedle patches, as well as their combination with regional delivery to the colon. This review critically examines four selected promising oral peptide technologies at preclinical stage and the twelve that have progressed to clinical trials, as indicated in www.clinicaltrials.gov. We examined these technologies under the criteria of peptide selection, formulation design, system components and excipients, intestinal mechanism of action, efficacy in man, and safety issues. The conclusion is that most of the technologies in clinical trials are incremental rather than paradigm-shifting and that even the more clinically advanced oral peptide drugs examples of oral bioavailability appear to yield oral bioavailability values of only 1-2% and are, therefore, only currently suitable for a limited range of peptides.
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Affiliation(s)
- T A S Aguirre
- Centro de Ciências Exatas e Tecnologia, Universidade de Caxias do Sul (UCS), Caxias do Sul, Brazil
| | - D Teijeiro-Osorio
- CIMUS Research Institute, University of Santiago de Compostela, Santiago de Compostela, Spain
| | - M Rosa
- Sigmoid Pharma, Dublin City University, Invent Centre, Dublin 9, Ireland
| | - I S Coulter
- Sigmoid Pharma, Dublin City University, Invent Centre, Dublin 9, Ireland
| | - M J Alonso
- CIMUS Research Institute, University of Santiago de Compostela, Santiago de Compostela, Spain.
| | - D J Brayden
- UCD School of Veterinary Medicine and UCD Conway Institute, University College Dublin, Belfield, Dublin 4, Ireland.
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17
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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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18
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McDermott FD, Folan DMA, Winter DC, Folan MA, Baird AW. Gnotobiotic Human Colon Ex Vivo. Gastroenterology Res 2015; 8:247-252. [PMID: 27785304 PMCID: PMC5051042 DOI: 10.14740/gr675w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 08/20/2015] [Indexed: 01/17/2023] Open
Abstract
Background A novel emulsion with efficacy as an agent for eliminating biofilms was selected. The aim of this study was to examine efficacy and effect of a formulation of ML:8 against commensal bacteria harvested from ex vivo human colonic tissues. Methods Mucosal sheets, obtained at the time of surgery, were exposed for 2 minutes to one of four solutions: Krebs-Hensleit (KH) solution, saline (NaCl; 0.9%), povidone iodine (1%), or ML:8 (2%); n = 4. Lumenal surfaces were swabbed for culture under aerobic or anaerobic conditions. Following treatment, each sheet was mounted in Ussing chambers and voltage clamped. Tissues were challenged with carbachol. Permeability coefficient (Papp) was determined using mannitol fluxes. At the end of each experiment, tissues were examined histologically. Results Similar colony forming units grew in aerobic and anaerobic conditions in both control and NaCl treated tissues. Iodine reduced and ML:8 virtually abolished viable bacteria. Basal electrophysiological parameters were not different between treatments. Transepithelial electrical resistance values did not differ between groups. All tissues responded to carbachol, although this was attenuated in iodine treated tissue. Papp values were slightly elevated in all treated tissues but this did not reach significance. Histopathological assessment revealed no overt damage to tissues. Conclusion Brief exposure to ML:8 reduced culturable bacterial burden from human intestinal tissues harvested at the time of surgical resection. Such gnotobiotic tissues retain structural and functional integrity. This is a novel approach to reduce bacterial burden.
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Affiliation(s)
- Frank D McDermott
- UCD School of Veterinary Medicine & Conway Institute of Biomolecular & Biomedical Science, University College Dublin, Belfield, Dublin 4, Ireland; UCD School of Medicine and Medical Science, University College Dublin, Belfield, Dublin 4, Ireland; These authors contributed equally to the study
| | - David M A Folan
- UCD School of Veterinary Medicine & Conway Institute of Biomolecular & Biomedical Science, University College Dublin, Belfield, Dublin 4, Ireland; These authors contributed equally to the study
| | - Des C Winter
- UCD School of Medicine and Medical Science, University College Dublin, Belfield, Dublin 4, Ireland; Department of Surgery, St Vincent's University Hospital, Elm Park, Dublin 4, Ireland
| | - Michael A Folan
- UCD School of Veterinary Medicine & Conway Institute of Biomolecular & Biomedical Science, University College Dublin, Belfield, Dublin 4, Ireland
| | - Alan W Baird
- UCD School of Veterinary Medicine & Conway Institute of Biomolecular & Biomedical Science, University College Dublin, Belfield, Dublin 4, Ireland
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19
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Luminal cysteine-proteases degrade colonic tight junction structure and are responsible for abdominal pain in constipation-predominant IBS. Am J Gastroenterol 2013; 108:1322-31. [PMID: 23711626 DOI: 10.1038/ajg.2013.152] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/22/2013] [Accepted: 04/22/2013] [Indexed: 12/11/2022]
Abstract
OBJECTIVES Luminal serine-proteases lead to increased colonic paracellular permeability and visceral hypersensitivity in patients with diarrhea-predominant irritable bowel syndrome (IBS-D). Other proteases, namely cysteine-proteases (CPs), increase airway permeability by digesting epithelial tight junction proteins. In this study, we focused on constipation-predominant IBS (IBS-C) and we aimed to (i) evaluate CP levels in two cohorts of IBS patients, (ii) test if IBS-C fecal supernatant (FSN) affects permeability, and visceral sensitivity after repeated administrations in mice, and (iii) evaluate occludin expression in IBS-C colonic biopsies. METHODS Fecal CP activity was determined using selective substrate and inhibitor (E64). The effect of papain, as positive control, and IBS-C FSN administrations were evaluated on colonic paracellular permeability and mucosal occludin levels in mice and T84 monolayers. Occludin protein levels were evaluated in IBS-C colonic biopsies. Sensitivity to colorectal distension (CRD) was measured after repeated administrations of IBS-C FSN. RESULTS We found in a subset of IBS-C patients an enhanced fecal CP activity, in comparison with healthy controls and IBS-D patients. CP activity levels positively correlated with disease severity and abdominal pain scoring. This association was confirmed by receiver operating characteristic curve analysis. In mice, repeated application of IBS-C FSN into colon triggered increased permeability, linked to the enzymatic degradation of occludin, and was associated with enhanced visceral sensitivity to CRD. Finally, occludin levels were found decreased in colonic biopsies from IBS-C patients, and IBS-C FSNs were able to degrade recombinant human occludin in vitro. All these effects were abolished by preincubation of IBS-C FSN with a CP inhibitor, E64. CONCLUSIONS These data suggest that luminal CPs may represent a new factor contributing to the genesis of symptoms in IBS.
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20
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A permeation enhancer for increasing transport of therapeutic macromolecules across the intestine. J Control Release 2013; 172:541-9. [PMID: 23680288 DOI: 10.1016/j.jconrel.2013.05.002] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2013] [Revised: 04/29/2013] [Accepted: 05/06/2013] [Indexed: 01/03/2023]
Abstract
Delivery of therapeutic macromolecules is limited by the physiological limitations of the gastrointestinal tract including poor intestinal permeability, low pH and enzymatic activity. Several permeation enhancers have been proposed to enhance intestinal permeability of macromolecules; however their utility is often hindered by toxicity and limited potency. Here, we report on a novel permeation enhancer, Dimethyl palmitoyl ammonio propanesulfonate (PPS), with excellent enhancement potential and minimal toxicity. PPS was tested for dose- and time-dependent cytotoxicity, delivery of two model fluorescent molecules, sulforhodamine-B and FITC-insulin in vitro, and absorption enhancement of salmon calcitonin (sCT) in vivo. Caco-2 studies revealed that PPS is an effective enhancer of macromolecular transport while being minimally toxic. TEER measurements in Caco-2 monolayers confirmed the reversibility of the effect of PPS. Confocal microscopy studies revealed that molecules permeate via both paracellular and transcellular pathways in the presence of PPS. In vivo studies in rats showed that PPS enhanced relative bioavailability of sCT by 45-fold after intestinal administration. Histological studies showed that PPS does not induce damage to the intestine. PPS is an excellent permeation enhancer which provides new opportunities for developing efficacious oral/intestinal delivery systems for therapeutic macromolecules.
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21
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Effects of pyridoxine on the intestinal absorption and pharmacokinetics of isoniazid in rats. Eur J Drug Metab Pharmacokinet 2012; 38:5-13. [PMID: 23090666 DOI: 10.1007/s13318-012-0106-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2012] [Accepted: 10/05/2012] [Indexed: 10/27/2022]
Abstract
Pyridoxine is always simultaneously administered orally with isoniazid for tuberculosis patients in the clinic to prevent or treat the nervous system side effects induced by isoniazid. So the aim of this research was to investigate the effects of pyridoxine on the intestinal absorption and pharmacokinetics of isoniazid. The intestinal absorption of isoniazid with or without pyridoxine was investigated by the rat single-pass intestinal perfusion model in situ, and a high-performance liquid chromatographic method was applied to study the pharmacokinetics of isoniazid with or without pyridoxine. The results suggested that the intestinal apparent permeability (P app) and intestinal absorption rate constant (K a) for isoniazid (30 μg/ml) were decreased by 43.7 and 36.4 %, respectively, by co-perfused pyridoxine (40 μg/ml). In vivo, the effect of pyridoxine on isoniazid pharmacokinetic correlated with the doses of pyridoxine. The blood concentrations of isoniazid at the absorption phase were affected by co-administered pyridoxine, but the AUC and C max of isoniazid were not greatly affected by pyridoxine as expected from the inhibition by pyridoxine of the intestinal absorption of isoniazid, which could be caused by its rapid absorption phase. Therefore, although the intestinal absorption of isoniazid could be significantly inhibited by pyridoxine, the pharmacokinetics of isoniazid oral administration was not greatly affected by the decreased intestinal absorption of isoniazid due to its rapid absorption.
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22
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Oral delivery of macromolecules: rationale underpinning Gastrointestinal Permeation Enhancement Technology (GIPET). Ther Deliv 2012; 2:1595-610. [PMID: 22833984 DOI: 10.4155/tde.11.132] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Oral delivery of macromolecular drugs, particularly peptides and proteins, is the focus of many academic and industrial laboratories. Armed with an increased understanding of the structure and regulation of intestinal epithelial junctional complexes of the paracellular barrier, the development of permeation enhancement technology initially focused on the specific and reversible opening of tight junctions in order to enable oral delivery. Despite intense research, none of these specific tight junction-opening technologies has yet been approved in an oral drug product, likely because of poor efficacy. Less specific enhancer technologies with a long history of safe use in man have additional surfactant-like effects on the transcellular pathway that lead to improved efficacy. These are likely to be the first to market for selected poorly permeable peptides. This review presents a summary of some approaches taken to intestinal permeation enhancement and explores in detail the oral delivery system developed by Merrion Pharmaceuticals, Gastrointestinal Permeation Enhancement Technology (GIPET).
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23
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Del Vecchio G, Tscheik C, Tenz K, Helms HC, Winkler L, Blasig R, Blasig IE. Sodium Caprate Transiently Opens Claudin-5-Containing Barriers at Tight Junctions of Epithelial and Endothelial Cells. Mol Pharm 2012; 9:2523-33. [DOI: 10.1021/mp3001414] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- G. Del Vecchio
- Leibniz-Institut für
Molekulare Pharmakologie, FMP, 13125 Berlin, Germany
| | - C. Tscheik
- Leibniz-Institut für
Molekulare Pharmakologie, FMP, 13125 Berlin, Germany
| | - K. Tenz
- Leibniz-Institut für
Molekulare Pharmakologie, FMP, 13125 Berlin, Germany
| | - H. C. Helms
- Department of Pharmacy, Faculty
of Medicines and Health, University of Copenhagen, Copenhagen, Denmark
| | - L. Winkler
- Leibniz-Institut für
Molekulare Pharmakologie, FMP, 13125 Berlin, Germany
| | - R. Blasig
- Leibniz-Institut für
Molekulare Pharmakologie, FMP, 13125 Berlin, Germany
| | - I. E. Blasig
- Leibniz-Institut für
Molekulare Pharmakologie, FMP, 13125 Berlin, Germany
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Maher S, Ryan KB, Ahmad T, O'driscoll CM, Brayden* DJ. Nanostructures Overcoming the Intestinal Barrier: Physiological Considerations and Mechanistic Issues. NANOSTRUCTURED BIOMATERIALS FOR OVERCOMING BIOLOGICAL BARRIERS 2012. [DOI: 10.1039/9781849735292-00039] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
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26
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Walsh EG, Maher S, Devocelle M, O'Brien PJ, Baird AW, Brayden DJ. High content analysis to determine cytotoxicity of the antimicrobial peptide, melittin and selected structural analogs. Peptides 2011; 32:1764-73. [PMID: 21703316 DOI: 10.1016/j.peptides.2011.06.006] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/29/2011] [Revised: 06/07/2011] [Accepted: 06/07/2011] [Indexed: 12/27/2022]
Abstract
Antimicrobial peptides (AMPs) are naturally occurring entities with potential as pharmaceutical candidates and/or food additives. They are present in many organisms including bacteria, insects, fish and mammals. While their antimicrobial activity is equipotent with many commercial antibiotics, current limitations are poor pharmacokinetics, stability and potential toxicology issues. Most elicit antimicrobial action via perturbation of bacterial membranes. Consequently, associated cytotoxicity in human cells is reflected by their capacity to lyse erythrocytes. However, more rigorous toxicological assessment of AMPs is required in order to predict potential failure at a later stage of development. We describe a high-content analysis (HCA) screening protocol recently established for determination and prediction of safety in pharmaceutical drug discovery. HCA is a powerful, multi-parameter bioanalytical tool that amalgamates the actions of fluorescence microscopy with automated cell analysis software in order to understand multiple changes in cellular health. We describe the application of HCA in assessing cytotoxicity of the cytolytic α-helical peptide, melittin, and selected structural analogs. The data shows that structural modification of melittin reduces its cytotoxic action and that HCA is suitable for rapidly identifying cytotoxicity.
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Affiliation(s)
- Edwin G Walsh
- UCD School of Veterinary Medicine and UCD Conway Institute, University College Dublin, Belfield, Dublin 4, Ireland
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27
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Cheng WP, Thompson C, Ryan SM, Aguirre T, Tetley L, Brayden DJ. In vitro and in vivo characterisation of a novel peptide delivery system: amphiphilic polyelectrolyte-salmon calcitonin nanocomplexes. J Control Release 2010; 147:289-97. [PMID: 20705108 DOI: 10.1016/j.jconrel.2010.07.128] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2010] [Revised: 07/29/2010] [Accepted: 07/31/2010] [Indexed: 11/16/2022]
Abstract
The cationic peptide, salmon calcitonin (sCT) was complexed with the cationic amphiphilic polyelectrolyte, poly(allyl)amine, grafted with palmitoyl and quaternary ammonium moieties at pH 5.0 and 7.4 to yield particulates (sCT-QPa). The complexes were approximately 200 nm in diameter, had zeta potentials ranging from +20 to +50 mV, and had narrow polydispersity indices (PDIs). Differential scanning calorimetry revealed the presence of an interaction between sCT and QPa in the complexes. Electron microscopy confirmed the zeta-size data and revealed a vesicular bilayer structure with an aqueous core. Tyrosine- and Nile red fluorescence indicated that the complexes retained gross physical stability for up to 7 days, but that the pH 5.0 complexes were more stable. The complexes were more resistant to peptidases, serum and liver homogenates compared to free sCT. In vitro bioactivity was measured by cAMP production in T47D cells and the complexes had EC50 values in the nM range. While free sCT was unable to generate cAMP following storage for 7 days, the complexes retained approximately 33% activity. When the complexes were injected intravenously to rats, free and complexed sCT (pH 5.0 and 7.4) but not QPa reduced serum calcium over 120 min. Free and complexed sCT but not QPa also reduced serum calcium over 240 min following intra-jejunal administration. In conclusion, sCT-QPa nanocomplexes that have been synthesised are stable, bioactive and resistant to a range of peptidases. These enhanced features suggest that they may have the potential for improved efficacy when formulated for injected and oral delivery.
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Affiliation(s)
- Woei-Ping Cheng
- School of Pharmacy, University of Hertfordshire, College Lane Hatfield AL10 9AB, UK
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Restoration of rat colonic epithelium after in situ intestinal instillation of the absorption promoter, sodium caprate. Ther Deliv 2010; 1:75-82. [DOI: 10.4155/tde.10.5] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Background: Sodium caprate (C10) is an oral absorption promoter that is currently in clinical trials as a component of solid dosage forms for poorly permeable small molecules and peptides. Clinical data with zoledronic acid tablets suggest that significant delivery along with acceptable safety can be achieved from a once-a-week dosing regime. C10 has surfactant-like properties at the high doses used in vivo and therefore we examined its effects on rat intestinal epithelium following intestinal instillation. Results: Addition of 100 mM concentrations of C10 with the paracellular flux marker, fluorescein isothiocyanate-dextran 4 kDa, permitted a bioavailability of 33% to be achieved. When C10 was added 10, 30 and 60 min in advance of fluorescein isothiocyanate-dextran 4 kDa, enhancement still occurred, but was progressively reduced. Histology revealed that the permeability increase was likely related in part to superficial epithelial damage caused in the first few minutes of exposure, which was rapidly repaired within 30–60 min. Conclusions: Design of optimized dosage forms containing C10 should corelease the payload and promoter close to the epithelium in high concentrations. While C10 induces some epithelial damage, its remarkable capacity for epithelial repair may render this effect insignificant in vivo.
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29
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Impact of amino acid replacements on in vitro permeation enhancement and cytotoxicity of the intestinal absorption promoter, melittin. Int J Pharm 2010; 387:154-60. [DOI: 10.1016/j.ijpharm.2009.12.022] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2009] [Revised: 12/08/2009] [Accepted: 12/09/2009] [Indexed: 10/20/2022]
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