1
|
Zhang BB, Chen XJ, Fan XD, Zhu JJ, Wei YH, Zheng HS, Zheng HY, Wang BH, Piao JG, Li FZ. Lipid/PAA-coated mesoporous silica nanoparticles for dual-pH-responsive codelivery of arsenic trioxide/paclitaxel against breast cancer cells. Acta Pharmacol Sin 2021; 42:832-842. [PMID: 33824461 PMCID: PMC8182795 DOI: 10.1038/s41401-021-00648-x] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2020] [Accepted: 03/12/2021] [Indexed: 02/01/2023] Open
Abstract
Nanomedicine has attracted increasing attention and emerged as a safer and more effective modality in cancer treatment than conventional chemotherapy. In particular, the distinction of tumor microenvironment and normal tissues is often used in stimulus-responsive drug delivery systems for controlled release of therapeutic agents at target sites. In this study, we developed mesoporous silica nanoparticles (MSNs) coated with polyacrylic acid (PAA), and pH-sensitive lipid (PSL) for synergistic delivery and dual-pH-responsive sequential release of arsenic trioxide (ATO) and paclitaxel (PTX) (PL-PMSN-PTX/ATO). Tumor-targeting peptide F56 was used to modify MSNs, which conferred a target-specific delivery to cancer and endothelial cells under neoangiogenesis. PAA- and PSL-coated nanoparticles were characterized by TGA, TEM, FT-IR, and DLS. The drug-loaded nanoparticles displayed a dual-pH-responsive (pHe = 6.5, pHendo = 5.0) and sequential drug release profile. PTX within PSL was preferentially released at pH = 6.5, whereas ATO was mainly released at pH = 5.0. Drug-free carriers showed low cytotoxicity toward MCF-7 cells, but ATO and PTX co-delivered nanoparticles displayed a significant synergistic effect against MCF-7 cells, showing greater cell-cycle arrest in treated cells and more activation of apoptosis-related proteins than free drugs. Furthermore, the extracellular release of PTX caused an expansion of the interstitial space, allowing deeper penetration of the nanoparticles into the tumor mass through a tumor priming effect. As a result, FPL-PMSN-PTX/ATO exhibited improved in vivo circulation time, tumor-targeted delivery, and overall therapeutic efficacy.
Collapse
Affiliation(s)
- Bing-Bing Zhang
- College of Pharmaceutical Sciences, Zhejiang Chinese Medical University, Hangzhou, 310053, China
| | - Xiao-Jie Chen
- College of Pharmaceutical Sciences, Zhejiang Chinese Medical University, Hangzhou, 310053, China
| | - Xu-Dong Fan
- College of Pharmaceutical Sciences, Zhejiang Chinese Medical University, Hangzhou, 310053, China
| | - Jing-Jing Zhu
- College of Pharmaceutical Sciences, Zhejiang Chinese Medical University, Hangzhou, 310053, China
| | - Ying-Hui Wei
- College of Pharmaceutical Sciences, Zhejiang Chinese Medical University, Hangzhou, 310053, China
| | - Hang-Sheng Zheng
- College of Pharmaceutical Sciences, Zhejiang Chinese Medical University, Hangzhou, 310053, China
| | - Hong-Yue Zheng
- Libraries of Zhejiang Chinese Medical University, Zhejiang Chinese Medical University, Hangzhou, 310053, China
| | - Bin-Hui Wang
- The Affiliated Municipal Hospital of Taizhou University, Taizhou, 318000, China.
| | - Ji-Gang Piao
- College of Pharmaceutical Sciences, Zhejiang Chinese Medical University, Hangzhou, 310053, China.
| | - Fan-Zhu Li
- College of Pharmaceutical Sciences, Zhejiang Chinese Medical University, Hangzhou, 310053, China.
| |
Collapse
|
2
|
Kozlovskaya V, Alford A, Dolmat M, Ducharme M, Caviedes R, Radford L, Lapi SE, Kharlampieva E. Multilayer Microcapsules with Shell-Chelated 89Zr for PET Imaging and Controlled Delivery. ACS Appl Mater Interfaces 2020; 12:56792-56804. [PMID: 33306342 DOI: 10.1021/acsami.0c17456] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Radionuclide-functionalized drug delivery vehicles capable of being imaged via positron emission tomography (PET) are of increasing interest in the biomedical field as they can reveal the in vivo behavior of encapsulated therapeutics with high sensitivity. However, the majority of current PET-guided theranostic agents suffer from poor retention of radiometal over time, low drug loading capacities, and time-limited PET imaging capability. To overcome these challenges, we have developed hollow microcapsules with a thin (<100 nm) multilayer shell as advanced theranostic delivery systems for multiday PET tracking in vivo. The 3 μm capsules were fabricated via the aqueous multilayer assembly of a natural antioxidant, tannic acid (TA), and a poly(N-vinylpyrrolidone) (PVPON) copolymer containing monomer units functionalized with deferoxamine (DFO) to chelate the 89Zr radionuclide, which has a half-life of 3.3 days. We have found using radiochromatography that (TA/PVPON-DFO)6 capsules retained on average 17% more 89Zr than their (TA/PVPON)6 counterparts, which suggests that the covalent attachment of the DFO to PVPON provides stable 89Zr chelation. In vivo PET imaging studies performed in mice demonstrated that excellent stability and imaging contrast were still present 7 days postinjection. Animal biodistribution analyses showed that capsules primarily accumulated in the spleen, liver, and lungs with negligible accumulation in the femur, with the latter confirming the stable binding of the radiotracer to the capsule walls. The application of therapeutic ultrasound (US) (60 s of 20 kHz US at 120 W cm-2) to Zr-functionalized capsules could release the hydrophilic anticancer drug doxorubicin from the capsules in the therapeutic amounts. Polymeric capsules with the capability of extended in vivo PET-based tracking and US-induced drug release provide an advanced platform for development of precision-targeted therapeutic carriers and could aid in the development of more effective drug delivery systems.
Collapse
Affiliation(s)
- Veronika Kozlovskaya
- Department of Chemistry, University of Alabama at Birmingham, Birmingham, Alabama 35294, United States
- Center for Nanomaterials and Biointegration, University of Alabama at Birmingham, Birmingham, Alabama 35294, United States
| | - Aaron Alford
- Department of Chemistry, University of Alabama at Birmingham, Birmingham, Alabama 35294, United States
| | - Maksim Dolmat
- Department of Chemistry, University of Alabama at Birmingham, Birmingham, Alabama 35294, United States
| | - Maxwell Ducharme
- Department of Radiology, University of Alabama at Birmingham, Birmingham, Alabama 35294, United States
| | - Racquel Caviedes
- Department of Chemistry, University of Alabama at Birmingham, Birmingham, Alabama 35294, United States
| | - Lauren Radford
- Department of Radiology, University of Alabama at Birmingham, Birmingham, Alabama 35294, United States
| | - Suzanne E Lapi
- Department of Radiology, University of Alabama at Birmingham, Birmingham, Alabama 35294, United States
| | - Eugenia Kharlampieva
- Department of Chemistry, University of Alabama at Birmingham, Birmingham, Alabama 35294, United States
- Center for Nanomaterials and Biointegration, University of Alabama at Birmingham, Birmingham, Alabama 35294, United States
| |
Collapse
|
3
|
Moulari B, Shetab Boushehri MA, Pais de Barros JP, Faber T, Béduneau A, Lagrost L, Pellequer Y, Lamprecht A. Nanosphere-shaped ammonio methacrylate copolymers: converting a pharmaceutical inactive ingredient to efficient therapeutics for experimental colitis. Nanoscale 2020; 12:9590-9602. [PMID: 32314992 DOI: 10.1039/d0nr00465k] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Inflammatory bowel disease (IBD) refers to progressive inflammatory disorders that impair the gastrointestinal tract's structure and function. Given their selective accumulation in inflamed tissues, nanoparticles are promising drug delivery systems for IBD treatment. The hypothesis here was that drug-free nanoscaled cationic ammonio methacrylate copolymers (AMCNP) may have a beneficial therapeutic effect in murine TNBS-induced colitis. Type A and B AMCNP (RLNP and RSNP, respectively) were prepared and characterized in vitro, and were rectally administered in two concentrations (5 and 25 mg ml-1) for the treatment of two grades of murine experimental colitis. The impact of the nanoparticles upon the inflammatory markers, circulating LPS, intestinal permeability and colonic leukocyte populations was examined. Both RLNP and RSNP led to a significant mitigation of mild to moderate experimental colitis, as evident from the substantial reduction of myeloperoxidase (MPO) and alkaline phosphatase (AP) activities (more than two-fold, P < 0.05) and various pro-inflammatory cytokine concentrations (TNF-α, IL-1β, IL-6, IL-12). The best therapeutic efficiency was observed when the particles were used at 5 mg ml-1, while the more cationic RLNP performed superior. When used against a severe grade of colitis, RLNP (5 mg ml-1) resulted in a significant decrease of tissue MPO and TNF-α. It was found that treatment with AMCNP resulted in significant intestinal immune cell depletion, intestinal barrier function improvement, and 1.5-2.5 times reduction of the systemic endotoxin concentration. These findings highlighted the fact that nanoscaling endows the cationic amphiphilic AMCs unique therapeutic properties, which help mitigate murine experimental colitis in the absence of any drug load. The results also provided a glimpse of possible underlying mechanisms through which nanoscaled AMCs might have exerted their therapeutic effect within this context.
Collapse
Affiliation(s)
- Brice Moulari
- PEPITE EA4267, Univ. Bourgogne Franche-Comte, Besançon, France.
| | | | | | | | | | | | | | | |
Collapse
|
4
|
Clegg JR, Irani AS, Ander EW, Ludolph CM, Venkataraman AK, Zhong JX, Peppas NA. Synthetic networks with tunable responsiveness, biodegradation, and molecular recognition for precision medicine applications. Sci Adv 2019; 5:eaax7946. [PMID: 31598554 PMCID: PMC6764836 DOI: 10.1126/sciadv.aax7946] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2019] [Accepted: 08/26/2019] [Indexed: 05/03/2023]
Abstract
Formulations and devices for precision medicine applications must be tunable and multiresponsive to treat heterogeneous patient populations in a calibrated and individual manner. We engineered modular poly(acrylamide-co-methacrylic acid) copolymers, cross-linked into multiresponsive nanogels with either a nondegradable or degradable disulfide cross-linker, that were customized via orthogonal chemistries to target biomarkers of an individual patient's disease or deliver multiple therapeutic modalities. Upon modification with functional small molecules, peptides, or proteins, these nanomaterials delivered methylene blue with environmental responsiveness, transduced visible light for photothermal therapy, acted as a functional enzyme, or promoted uptake by cells. In addition to quantifying the nanogels' composition, physicochemical characteristics, and cytotoxicity, we used a QCM-D method for characterizing nanomaterial degradation and a high-throughput assay for cellular uptake. In conclusion, we generated a tunable nanogel composition for precision medicine applications and new quantitative protocols for assessing the bioactivity of similar platforms.
Collapse
Affiliation(s)
- John R. Clegg
- Department of Biomedical Engineering, The University of Texas at Austin, Austin, TX, USA
| | - Afshan S. Irani
- Department of Biomedical Engineering, The University of Texas at Austin, Austin, TX, USA
| | - Eric W. Ander
- McKetta Department of Chemical Engineering, The University of Texas at Austin, Austin, TX, USA
| | - Catherine M. Ludolph
- McKetta Department of Chemical Engineering, The University of Texas at Austin, Austin, TX, USA
| | | | - Justin X. Zhong
- McKetta Department of Chemical Engineering, The University of Texas at Austin, Austin, TX, USA
| | - Nicholas A. Peppas
- Department of Biomedical Engineering, The University of Texas at Austin, Austin, TX, USA
- McKetta Department of Chemical Engineering, The University of Texas at Austin, Austin, TX, USA
- Institute for Biomaterials, Drug Delivery, and Regenerative Medicine, The University of Texas at Austin, Austin, TX, USA
- Division of Molecular Pharmaceutics and Drug Delivery, College of Pharmacy, The University of Texas at Austin, Austin, TX, USA
- Department of Surgery and Perioperative Care, and Department of Pediatrics, Dell Medical School, The University of Texas at Austin, Austin, TX, USA
| |
Collapse
|
5
|
Song Q, Jia J, Niu X, Zheng C, Zhao H, Sun L, Zhang H, Wang L, Zhang Z, Zhang Y. An oral drug delivery system with programmed drug release and imaging properties for orthotopic colon cancer therapy. Nanoscale 2019; 11:15958-15970. [PMID: 31418432 DOI: 10.1039/c9nr03802g] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Oral drug delivery systems (ODDSs) have attracted considerable attention in relation to orthotopic colon cancer therapy due to certain popular advantages. Unfortunately, their clinical applications are generally limited by the side-effects caused by systemic drug exposure and poor real-time monitoring capabilities. Inspired by the characteristics of pH changes of the gastrointestinal tract (GIT) and specific enzymes secreted by the colonic microflora, we anchored polyacrylic acid (PAA) and chitosan (CS) on Gd3+-doped mesoporous hydroxyapatite nanoparticles (Gd-MHAp NPs) to realize programmed drug release and magnetic resonance imaging (MRI) at the tumor sites. In particular, the grafted PAA, as a pH-responsive switch, could effect controlled drug release in the colon. Further, CS is functionalized as the enzyme-sensitive moiety, which could be degraded by β-glycosidase in the colon. Gadolinium is a paramagnetic lanthanide element used in chelates, working as a contrast medium agent for an MRI system. Interestingly, after oral administration, CS and PAA could protect the drug-loaded nanoparticles (NPs) against variable physiological conditions in the GIT, allowing the drug to reach the colon tumor sites, preventing premature drug release. Enhanced drug concentrations at the colon tumor sites were achieved via this programmed drug release, which subsequently ameliorated the therapeutic effect. In addition, encapsulating both chemotherapeutic (5-fluorouracil, 5-FU) and targeted therapy drug (gefitinib, Gef) within Gd-MHAp NPs produced a synergistic therapeutic effect. In summary, this study demonstrated that such a novel drug system (Gd-MHAp/5-FU/Gef/CS/PAA NPs) could protect, transport, and program drug release locally within the colonic environment; further, this system exhibited a worthwhile therapeutic effect, providing a promising novel treatment strategy for orthotopic colon cancer.
Collapse
Affiliation(s)
- Qingling Song
- School of Pharmaceutical Sciences, Zhengzhou University, 100 Kexue Avenue, Zhengzhou 450001, China.
| | | | | | | | | | | | | | | | | | | |
Collapse
|
6
|
Corti M, Calleri E, Perteghella S, Ferrara A, Tamma R, Milanese C, Mandracchia D, Brusotti G, Torre ML, Ribatti D, Auricchio F, Massolini G, Tripodo G. Polyacrylate/polyacrylate-PEG biomaterials obtained by high internal phase emulsions (HIPEs) with tailorable drug release and effective mechanical and biological properties. Mater Sci Eng C Mater Biol Appl 2019; 105:110060. [PMID: 31546370 DOI: 10.1016/j.msec.2019.110060] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/10/2019] [Revised: 07/22/2019] [Accepted: 08/07/2019] [Indexed: 01/03/2023]
Abstract
The paper focuses on the preparation of polyacrylate based biomaterials designed as patches for dermal/transdermal drug delivery using materials obtained by the high internal phase emulsion (HIPE) technique. In particular, butyl acrylate and glycidyl methacrylate were selected, respectively, as backbone and functional monomer while two different crosslinkers, bifunctional or trifunctional, were used to form the covalent network. The influence of PEG on the main properties of the materials was also investigated. The obtained materials show a characteristic and interconnected internal structure as confirmed by SEM studies. By an industrial point of view, an interesting feature of this system is that it can be shaped as needed, in any form and thickness. The physiochemically characterized materials showed a tailorable curcumin (model of hydrophobic drugs) drug release, effective mechanical properties and cell viability and resulted neither pro nor anti-angiogenic as demonstrated in vivo by the chick embryo choriallantoic membrane (CAM) assay. Based on these results, the obtained polyHIPEs could be proposed as devices for dermal/transdermal drug delivery and/or for the direct application on wounded skin.
Collapse
Affiliation(s)
- Marco Corti
- Department of Drug Sciences, University of Pavia, Viale Taramelli 12-14, Pavia 27100, Italy
| | - Enrica Calleri
- Department of Drug Sciences, University of Pavia, Viale Taramelli 12-14, Pavia 27100, Italy.
| | - Sara Perteghella
- Department of Drug Sciences, University of Pavia, Viale Taramelli 12-14, Pavia 27100, Italy
| | - Anna Ferrara
- Department of Civil Engineering and Architecture, University of Pavia, Via Adolfo Ferrata 3, Pavia 27100, Italy
| | - Roberto Tamma
- Department of Basic Medical Sciences, Neurosciences, and Sensory Organs, University of Bari Medical School, Piazza Giulio Cesare 11, Bari 70100, Italy
| | - Chiara Milanese
- C.S.G.I. - Department of Chemistry, Physical-Chemistry Section, University of Pavia, Viale Taramelli 16, Pavia 27100, Italy
| | - Delia Mandracchia
- Department of Pharmacy-Drug Sciences, University of Bari "Aldo Moro", Via Orabona 4, Bari 70125, Italy
| | - Gloria Brusotti
- Department of Drug Sciences, University of Pavia, Viale Taramelli 12-14, Pavia 27100, Italy
| | - Maria Luisa Torre
- Department of Drug Sciences, University of Pavia, Viale Taramelli 12-14, Pavia 27100, Italy
| | - Domenico Ribatti
- Department of Basic Medical Sciences, Neurosciences, and Sensory Organs, University of Bari Medical School, Piazza Giulio Cesare 11, Bari 70100, Italy
| | - Ferdinando Auricchio
- Department of Civil Engineering and Architecture, University of Pavia, Via Adolfo Ferrata 3, Pavia 27100, Italy
| | - Gabriella Massolini
- Department of Drug Sciences, University of Pavia, Viale Taramelli 12-14, Pavia 27100, Italy
| | - Giuseppe Tripodo
- Department of Drug Sciences, University of Pavia, Viale Taramelli 12-14, Pavia 27100, Italy.
| |
Collapse
|
7
|
Wu J, Zheng Y, Jiang S, Qu Y, Wei T, Zhan W, Wang L, Yu Q, Chen H. Two-in-One Platform for High-Efficiency Intracellular Delivery and Cell Harvest: When a Photothermal Agent Meets a Thermoresponsive Polymer. ACS Appl Mater Interfaces 2019; 11:12357-12366. [PMID: 30859807 DOI: 10.1021/acsami.9b01586] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Efficient intracellular delivery of exogenous macromolecules is a key operation in biological research and for clinical applications. Moreover, under particular in vitro or ex vivo conditions, harvesting the engineered cells that maintain good viability is also important. However, none of the methods currently available is truly satisfactory in all respects. Herein, a "two-in-one" platform based on a polydopamine/poly( N-isopropylacrylamide) (PDA/PNIPAAm) hybrid film is developed, showing high efficiency in both cargo delivery and cell harvest without compromising cell viability. Due to the strong photothermal effect of PDA in response to near-infrared irradiation, this film can deliver diverse molecules to a number of cell types (including three hard-to-transfect cells) with an efficiency of ∼99% via membrane-disruption mechanism. Moreover, due to the thermoresponsive properties of PNIPAAm, the cells are harvested from the film without compromising viability by simply decreasing the temperature. A proof-of-concept experiment demonstrates that, using this platform, "recalcitrant" endothelial cells can be transfected by the functional ZNF580 gene and the harvested transfected cells can be recultured with high retention of viability and improved migration. In general, this "two-in-one" platform provides a reliable, universally applicable approach for both intracellular delivery and cell harvest in a highly efficient and nondestructive way, with great potential for use in a wide range of biomedical applications.
Collapse
Affiliation(s)
- Jingxian Wu
- State and Local Joint Engineering Laboratory for Novel Functional Polymeric Materials, College of Chemistry, Chemical Engineering and Materials Science , Soochow University , 199 Ren'ai Road , Suzhou 215123 , P. R. China
| | - Yanjun Zheng
- State and Local Joint Engineering Laboratory for Novel Functional Polymeric Materials, College of Chemistry, Chemical Engineering and Materials Science , Soochow University , 199 Ren'ai Road , Suzhou 215123 , P. R. China
| | - Shuaibing Jiang
- State and Local Joint Engineering Laboratory for Novel Functional Polymeric Materials, College of Chemistry, Chemical Engineering and Materials Science , Soochow University , 199 Ren'ai Road , Suzhou 215123 , P. R. China
| | - Yangcui Qu
- State and Local Joint Engineering Laboratory for Novel Functional Polymeric Materials, College of Chemistry, Chemical Engineering and Materials Science , Soochow University , 199 Ren'ai Road , Suzhou 215123 , P. R. China
| | - Ting Wei
- State and Local Joint Engineering Laboratory for Novel Functional Polymeric Materials, College of Chemistry, Chemical Engineering and Materials Science , Soochow University , 199 Ren'ai Road , Suzhou 215123 , P. R. China
| | - Wenjun Zhan
- State and Local Joint Engineering Laboratory for Novel Functional Polymeric Materials, College of Chemistry, Chemical Engineering and Materials Science , Soochow University , 199 Ren'ai Road , Suzhou 215123 , P. R. China
| | - Lei Wang
- State and Local Joint Engineering Laboratory for Novel Functional Polymeric Materials, College of Chemistry, Chemical Engineering and Materials Science , Soochow University , 199 Ren'ai Road , Suzhou 215123 , P. R. China
| | - Qian Yu
- State and Local Joint Engineering Laboratory for Novel Functional Polymeric Materials, College of Chemistry, Chemical Engineering and Materials Science , Soochow University , 199 Ren'ai Road , Suzhou 215123 , P. R. China
| | - Hong Chen
- State and Local Joint Engineering Laboratory for Novel Functional Polymeric Materials, College of Chemistry, Chemical Engineering and Materials Science , Soochow University , 199 Ren'ai Road , Suzhou 215123 , P. R. China
| |
Collapse
|
8
|
Altinbasak I, Jijie R, Barras A, Golba B, Sanyal R, Bouckaert J, Drider D, Bilyy R, Dumych T, Paryzhak S, Vovk V, Boukherroub R, Sanyal A, Szunerits S. Reduced Graphene-Oxide-Embedded Polymeric Nanofiber Mats: An "On-Demand" Photothermally Triggered Antibiotic Release Platform. ACS Appl Mater Interfaces 2018; 10:41098-41106. [PMID: 30376295 DOI: 10.1021/acsami.8b14784] [Citation(s) in RCA: 48] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
The steady increase of antimicrobial resistance of different pathogens requires the development of alternative treatment strategies next to the oral delivery of antibiotics. A photothermally activated platform based on reduced graphene oxide (rGO)-embedded polymeric nanofiber mats for on-demand release of antibiotics upon irradiation in the near-infrared is fabricated. Cross-linked hydrophilic nanofibers, obtained by electrospinning a mixture of poly(acrylic acid) (PAA) and rGO, show excellent stability in aqueous media. Importantly, these PAA@ rGO nanofiber mats exhibit controlled photothermal heating upon irradiation at 980 nm. Nanofiber mats are efficiently loaded with antibiotics through simple immersion into corresponding antibiotics solutions. Whereas passive diffusion based release at room temperature is extremely low, photothermal activation results in increased release within few minutes, with release rates tunable through power density of the applied irradiation. The large difference over passive and active release, as well as the controlled turn-on of release allow regulation of the dosage of the antibiotics, as evidenced by the inhibition of planktonic bacteria growth. Treatment of superficial skin infections with the antibiotic-loaded nanofiber mats shows efficient wound healing of the infected site. Facile fabrication and implementation of these photothermally active nanofiber mats makes this novel platform adaptable for on-demand delivery of various therapeutic agents.
Collapse
Affiliation(s)
| | - Roxana Jijie
- Université de Lille, CNRS, Centrale Lille , ISEN, Université de Valenciennes, UMR 8520 - IEMN , F-59000 Lille , France
| | - Alexandre Barras
- Université de Lille, CNRS, Centrale Lille , ISEN, Université de Valenciennes, UMR 8520 - IEMN , F-59000 Lille , France
| | | | - Rana Sanyal
- RS Research Inc., Teknopark Istanbul , Pendik, 34912 Istanbul , Turkey
| | - Julie Bouckaert
- Unité de Glycobiologie Structurale et Fonctionnelle (UGSF) , UMR 8576 du CNRS et Université de Lille , 50 Avenue de Halley , 59658 Villeneuve d'Ascq , France
| | - Djamel Drider
- Institut Charles Viollette , Université de Lille , EA 7394 Lille , France
| | - Rostyslav Bilyy
- Danylo Halytsky Lviv National Medical University , 79010 Lviv , Ukraine
| | - Tetiana Dumych
- Danylo Halytsky Lviv National Medical University , 79010 Lviv , Ukraine
| | - Solomiya Paryzhak
- Danylo Halytsky Lviv National Medical University , 79010 Lviv , Ukraine
| | - Volodymyr Vovk
- Danylo Halytsky Lviv National Medical University , 79010 Lviv , Ukraine
| | - Rabah Boukherroub
- Université de Lille, CNRS, Centrale Lille , ISEN, Université de Valenciennes, UMR 8520 - IEMN , F-59000 Lille , France
| | | | - Sabine Szunerits
- Université de Lille, CNRS, Centrale Lille , ISEN, Université de Valenciennes, UMR 8520 - IEMN , F-59000 Lille , France
| |
Collapse
|
9
|
Beber TC, de Andrade DF, Chaves PDS, Pohlmann AR, Guterres SS, Beck RCR. Cationic Polymeric Nanocapsules as a Strategy to Target Dexamethasone to Viable Epidermis: Skin Penetration and Permeation Studies. J Nanosci Nanotechnol 2016; 16:1331-8. [PMID: 27433583 DOI: 10.1166/jnn.2016.11670] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
The present work aimed to evaluate the behavior of dexamethasone-loaded cationic polymericnanocapsules in hydrogels, regarding their in vitro drug release and skin drug retention and per- meation. Cationic polymeric nanocapsules prepared with Eudragit RS 100 as the polymeric wall had mean particle size of 139 +/- 3.6 nm, positive zeta potential (+11.38 +/- 1.7 mV), and high encapsulation efficiency (81 +/- 2%). After preparation, they were formulated as hydrogels, which showed non-Newtonian, plastic behavior, and acidic pH. Photon correlation spectroscopy analysis of these hydrogels demonstrated the presence of particles with mean particle size close to that of the original colloidal suspensions. The presence of dexamethasone-loaded nanocapsules in hydrogels promoted controlled drug release and an increase in the amount of drug delivered into viable epidermis, the main target tissue to topical glucocorticoid action. Moreover, the formulation did not increase the risk of drug penetration to dermis and permeation to the receptor compartment.
Collapse
|
10
|
Jiang W, Chen B, Wu J, Xu S, Tian R. Synthesis and Evaluation of Thermo-Sensitive, Magnetic Fluorescent Nanocomposite as Trifunctional Drug Delivery Carrier. J Nanosci Nanotechnol 2016; 16:246-252. [PMID: 27398451 DOI: 10.1166/jnn.2016.10675] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
The thermo-sensitive magnetic fluorescent trifunctional nanocomposite (Fe₃O₄/ZnS@PNIPAM) has been synthesized via a facile route. The obtained biocompatible nanocomposite was composed of monodisperse heterostructural Fe₃O₄/ZnS core and a thermo-sensitive poly(N-isopropyl acrylamide) (PNIPAM) shell. Fe₃O₄/ZnS acted as magnetic response and fluorescence luminous body, PNIPAM acted as drug loaded platform which can adsorb and release drug controllably. Fe₃O₄/ZnS@PNIPAM was characterized and all of the results showed that it had excellent magnetic response, photostability and thermo-sensitivity. Moreover, the drug release studies in vitro showed that the release rate increased with increasing temperature. MTT assays in model HepG2 cells demonstrated that Fe₃O₄/ZnS@PNIPAM was practically non-toxic. Thus, our results revealed that Fe₃O₄/ZnS@PNIPAM would be used in biomedical fields such as targeted drug delivery, as well as cancer diagnosis and treatment in the nearly future.
Collapse
|
11
|
Song S, Guo H, Jiang Z, Jin Y, Wu Y, An X, Zhang Z, Sun K, Dou H. Self-assembled microbubbles as contrast agents for ultrasound/magnetic resonance dual-modality imaging. Acta Biomater 2015; 24:266-78. [PMID: 26112374 DOI: 10.1016/j.actbio.2015.06.025] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2015] [Revised: 05/29/2015] [Accepted: 06/17/2015] [Indexed: 01/26/2023]
Abstract
In this work, superparamagnetic self-assembled microbubbles (SAMBs) consisting of "Poly(acrylic acid)-Iron oxide nanoparticles-Polyamine" sandwich-like shells and tetradecafluorohexane cores were fabricated by a template-free self-assembly approach. The SAMBs exhibit not only magnetic resonance (MR) T2 imaging functionality, but also ultrasound (US) image contrast, showing great potential as US/MR dual contrast agents. The diameters of the SAMBs can be tuned easily from 450nm to 1300nm by changing the precursor ratio, and this size variation directly affects their in vitro MRI and US signals. The SAMBs also exhibit in vivo contrast enhancement capabilities in rat liver with injection through portal vein, for both MR and US imaging. Additionally, the biodistribution of SAMBs over time suggests normal systemic metabolic activity through the spleen. The results show that the Fe content in rat liver reduces to a level of which Fe cannot be detected in 45days. The SAMBs exhibit no obvious damage to the primary organs of rat during the metabolic process, indicating their good biocompatibility in vivo.
Collapse
Affiliation(s)
- Sheng Song
- The State Key Laboratory of Metal Matrix Composites, School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, PR China
| | - Heze Guo
- The State Key Laboratory of Metal Matrix Composites, School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, PR China
| | - Zequan Jiang
- The State Key Laboratory of Metal Matrix Composites, School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, PR China
| | - Yuqing Jin
- Department of Plastic and Reconstructive Surgery, Shanghai First People's Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200080, PR China
| | - Ying Wu
- Department of Ultrasound, Shanghai First People's Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200080, PR China
| | - Xiao An
- Department of Neoplasms and Interventional Radiology, Shanghai First People's Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200080, PR China
| | - Zhaofeng Zhang
- Department of Plastic and Reconstructive Surgery, Shanghai First People's Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200080, PR China.
| | - Kang Sun
- The State Key Laboratory of Metal Matrix Composites, School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, PR China.
| | - Hongjing Dou
- The State Key Laboratory of Metal Matrix Composites, School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, PR China.
| |
Collapse
|
12
|
Arif H, Al-Masum A, Sharmin F, Reza S, Sm Islam SA. Formulation of bi-layer matrix tablets of tramadol hydrochloride: Comparison of rate retarding ability of the incorporated hydrophilic polymers. Pak J Pharm Sci 2015; 28:855-861. [PMID: 26004717] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Bi-layer tablets of tramadol hydrochloride were prepared by direct compression technique. Each tablet contains an instant release layer with a sustained release layer. The instant release layer was found to release the initial dose immediately within minutes. The instant release layer was combined with sustained release matrix made of varying quantity of Methocel K4M, Methocel K15MCR and Carbomer 974P. Bi-layer tablets were evaluated for various physical tests including weight variation, thickness and diameter, hardness and percent friability. Drug release from bi-layer tablet was studied in acidic medium and buffer medium for two and six hours respectively. Sustained release of tramadol hydrochloride was observed with a controlled fashion that was characteristic to the type and extent of polymer used. % Drug release from eight-hour dissolution study was fitted with several kinetic models. Mean dissolution time (MDT) and fractional dissolution values (T25%, T50% and T80%) were also calculated as well, to compare the retarding ability of the polymers. Methocel K15MCR was found to be the most effective in rate retardation of freely water-soluble tramadol hydrochloride compared to Methocel K4M and Capbomer 974P, when incorporated at equal ratio in the formulation.
Collapse
Affiliation(s)
- Hasanul Arif
- Department of Pharmacy, University of Asia Pacific, Dhanmondi, Dhaka, Bangladesh
| | - Abdullah Al-Masum
- Research & Development Formulation Department, Incepta Pharmaceuticals Ltd., Savar, Dhaka, Bangladesh
| | - Florida Sharmin
- Department of Pharmacy, University of Asia Pacific, Dhanmondi, Dhaka, Bangladesh
| | - Selim Reza
- Department of Pharmaceutical Technology, Faculty of Pharmacy, University of Dhaka, Dhaka, Bangladesh
| | - Sm Ashraful Sm Islam
- Department of Pharmacy, University of Asia Pacific, Dhanmondi, Dhaka, Bangladesh
| |
Collapse
|
13
|
Abstract
BACKGROUND The concept of closed-loop control of glucose, in which continuous glucose sensing is coupled to a fully automated insulin delivery device, without human input, has been an attractive idea for diabetes management. This study presents a new class of hybrid nanogels that can integrate glucose sensing and glucose-responsive insulin release into a single nano-object. METHODS Zinc oxide@poly[N-isopropylacrylamide (NIPAM)-acrylamide (AAm)- 2-aminomethyl-5-fluorophenylboronic acid (FPBA)] hybrid nanogels were synthesized and investigated for size, morphology, volume phase transition, photoluminescence properties, and in vitro insulin release under different glucose concentrations. Glucose sensing was performed both in phosphate-buffered saline (PBS) and in blood samples. The insulin release in PBS of varying glucose levels, as well as a stepwise treatment between two glucose levels (126.0 and 270.0 mg/dl), was performed to test the glucose-responsive insulin release ability of the hybrid nanogels. RESULTS Zinc oxide@poly(NIPAM-AAm-FPBA) hybrid nanogels can sensitively and selectively detect glucose in highly reproducible fluorescent signals over the clinically relevant glucose concentration range of 18-540 mg/dl. The glucose-responsive volume phase transition of the nanogels can further regulate the release of the preloaded insulin. The insulin release from the nanogels exhibits the slowest rate (~5% released in 76 h) at a normal glucose level (108.0 mg/dl) but becomes quicker and quicker as the glucose increases to higher and higher levels. CONCLUSIONS The rationally designed hybrid nanogel can optically signal the glucose level with high sensitivity and selectivity and simultaneously regulate the insulin release rate in response to the glucose reading, which shows a promising concept toward the development of a miniaturized closed-loop glycemic control system.
Collapse
Affiliation(s)
- Weitai Wu
- Department of Chemistry, College of Staten Island, Graduate Center, City University of New York, Staten Island, New York, USA.
| | | | | | | |
Collapse
|
14
|
Müller M, Karg M, Fortini A, Hellweg T, Fery A. Wrinkle-assisted linear assembly of hard-core/soft-shell particles: impact of the soft shell on the local structure. Nanoscale 2012; 4:2491-2499. [PMID: 22395669 DOI: 10.1039/c2nr11591c] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
This article addresses wrinkle assisted assembly of core-shell particles with hard cores and soft poly-(N-isopropylacrylamide) shells. As core materials we chose silica as well as silver nanoparticles. The assembled structures show that the soft shells act as a separator between the inorganic cores. Anisotropic alignment is found on two length scales, macroscopically guided through the wrinkle structure and locally due to deformation of the polymer shell leading to smaller inter-core separations as compared to assembly on flat substrates without confinement. The structures were analysed by means of scanning electron microscopy. Radial distribution functions are shown, clearly highlighting the impact of confinement on nearest neighbour distances and symmetry. The observed ordering is directly compared to Monte-Carlo simulations for hard-core/soft-shell particles, showing that the observed symmetries are a consequence of the soft interaction potential and differ qualitatively from a hard-sphere situation. For the silver-poly-(N-isopropylacrylamide) particles, we show UV-vis absorbance measurements revealing optical anisotropy of the generated structures due to plasmon coupling. Furthermore, the high degree of order of the assembled structures on macroscopic areas is demonstrated by laser diffraction effects.
Collapse
Affiliation(s)
- Mareen Müller
- Physical Chemistry II, University of Bayreuth, Universitaetsstrasse 30, 95447 Bayreuth, Germany
| | | | | | | | | |
Collapse
|
15
|
Mohamed SP, Muzzammil S, Pramod KTM. Preparation of fluconazole buccal tablet and influence of formulation expedients on its properties. Yao Xue Xue Bao 2011; 46:460-465. [PMID: 21748974] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
The aim of present study was to prepare buccal tablets of fluconazole for oral candidiasis. The dosage forms were designed to release the drug above the minimum inhibitory concentration for prolonged period of time so as to reduce the frequency of administration and to overcome the side effects of systemic treatment. The buccal tablets were prepared by using Carbopol 71G and Noveon AA-1 by direct compression method. Microcrystalline cellulose was used as the filler and its effect was also studied. The prepared dosage forms were evaluated for physicochemical properties, in vitro release studies and mucoadhesive properties using sheep buccal mucosa as a model tissue. Tablets containing 50% of polymers (Carbopol & Noveon) were found to be the best with moderate swelling along with favorable bioadhesion force, residence time and in vitro drug release. The in vitro drug release studies revealed that drug released for 8 h, which in turn may reduce dosing frequency and improved patient compliance in oral candidiasis patients.
Collapse
Affiliation(s)
- Saifulla P Mohamed
- Department of Pharmaceutics, College of Pharmacy, JSS University, Sri Shivarathreeshwara Nagar, Mysore-570 015, Karnataka, India.
| | | | | |
Collapse
|
16
|
Xu HHK, Weir MD, Sun L, Ngai S, Takagi S, Chow LC. Effect of filler level and particle size on dental caries-inhibiting Ca-PO(4) composite. J Mater Sci Mater Med 2009; 20:1771-9. [PMID: 19365616 PMCID: PMC3056554 DOI: 10.1007/s10856-009-3740-2] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/07/2008] [Accepted: 03/23/2009] [Indexed: 05/27/2023]
Abstract
Secondary caries and restoration fracture are common problems in restorative dentistry. The aim of this study was to develop Ca-PO(4) nanocomposite having improved stress-bearing properties and Ca and PO(4) ion release to inhibit caries, and to determine the effects of filler level. Nanoparticles of dicalcium phosphate anhydrous (DCPA), two larger DCPA powders, and reinforcing whiskers were incorporated into a resin. A 6 x 3 design was tested with six filler mass fractions (0, 30, 50, 65, 70, and 75%) and three DCPA particle sizes (112 nm, 0.88 mum, 12.0 mum). The DCPA nanocomposite at 75% fillers had a flexural strength (mean +/- SD; n = 6) of 114 +/- 23 MPa, matching the 112 +/- 22 MPa of a commercial non-releasing, hybrid composite (P > 0.1). This was 2-fold of the 60 +/- 6 MPa of a commercial releasing control. Decreasing the particle size increased the ion release. Increasing the filler level increased the ion release at a rate faster than being linear. The amount of ion release from the nanocomposite matched or exceeded those of previous composites that released supersaturating levels of Ca and PO(4) and remineralized tooth lesions. This suggests that the much stronger nanocomposite may also be effective in remineralizing tooth lesion and inhibiting caries. In summary, combining calcium phosphate nanoparticles with reinforcing co-fillers in the composite provided a way to achieving both caries-inhibiting and stress-bearing capabilities. Filler level and particle size can be tailored to achieve optimal composite properties.
Collapse
Affiliation(s)
- Hockin H K Xu
- Department of Endodontics, Prosthodontics and Operative Dentistry, University of Maryland Dental School, Baltimore, MD 21201, USA.
| | | | | | | | | | | |
Collapse
|
17
|
Aqil M, Sultana Y, Ali A, Dubey K, Najmi AK, Pillai KK. Transdermal Drug Delivery Systems of a Beta Blocker: Design, In Vitro, and In Vivo Characterization. Drug Deliv 2008; 11:27-31. [PMID: 15168788 DOI: 10.1080/10717540490265225] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022] Open
Abstract
The matrix type transdermal drug delivery systems (TDDS) of metoprolol were prepared by film casting technique using a fabricated stainless steel film casting apparatus and characterized in vitro by drug release, skin permeation, skin irritation, and in vivo pharmacodynamic and stability studies. Four formulations were prepared that differed in the ratio of matrix forming polymers. Formulations M-1, M-2, M-3, and M-4 were composed of Eudragit RL-100 and polyvinyl acetate with the following ratios: 2:8, 4:6, 6:4, and 8:2, respectively. All the four formulations carried 10% (w/w) of metoprolol tartrate, 5% (w/w) of dibutylphthalate, and 5% (w/w) of (+/-) menthol in dichloromethane:isopropyl alcohol (80:20 v/v). Cumulative amount of drug released in 48 hr from the four formulations was 79.16%, 81.17%, 85.98%, and 95.04%. The corresponding values for cumulative amount of drug permeated for the said formulations were 59.72%, 66.52%, 77.36%, and 90.38%. On the basis of in vitro drug release and skin permeation performance, formulation M-4 was found to be better than the other three formulations and it was selected as the optimized formulation. The formulation appeared to be stable when stored at 40 degrees C and 75% RH with negligible degradation of the drug. The TDDS was found to be free of any skin irritation as suggested by skin irritation score of 1.16 (<2.00) under Draize score test. Statistically significant reduction in mean blood pressure (p < .01) was achieved in methyl prednisolone-induced hypertensive rats on treatment with the TDDS.
Collapse
Affiliation(s)
- M Aqil
- Department of Pharmaceutics, Faculty of Pharmacy, Hamdard University, New Delhi, India.
| | | | | | | | | | | |
Collapse
|
18
|
Lewis G, Coughlan DC, Lane ME, Corrigan OI. Preparation and release of model drugs from thermally sensitive poly(N-isopropylacrylamide) based macrospheres. J Microencapsul 2008; 23:677-85. [PMID: 17118883 DOI: 10.1080/02652040600789237] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Emulsion polymerization was employed to prepare poly(N-isopropylacrylamide) hydrogel spheres, which exhibited an LCST of 32 degrees C. The hydrogels were loaded with model drugs (benzoic acid (BA), sodium benzoate and diltiazem HCl (DHCl)) and release investigated at 25 degrees C and 37 degrees C. The temperature at which gel formation occurred was vital for successful hydrogel preparation, macrosphere formation not occurring when the temperature was close to the LCST. Sphere size increased on decreasing the stirring rate and on slowing the rate of addition of the aqueous phase. Pulsatile delivery was investigated using BA and DHCl. For both compounds a pulse was observed with a change in temperature. Pulsed release of the smaller model drug of lowest solubility, BA, was more successful. Drug release from hydrogel spheres was, therefore, found to be dependent on the physicochemical properties of the drugs, with pulsatile release of low molecular weight compounds, by temperature cycling, difficult to control.
Collapse
Affiliation(s)
- G Lewis
- School of Pharmacy and Pharmaceutical Sciences, University of Dublin, Trinity College, Dublin, Ireland
| | | | | | | |
Collapse
|
19
|
Lavisse S, Peronneau P, Rouffiac V, Paci A, Vigouroux J, Opolon P, Roche A, Lassau N. Acoustic characterization of a new trisacryl contrast agent. Part II: Flow phantom study and in vivo quantification. Ultrasonics 2008; 48:26-34. [PMID: 18191434 DOI: 10.1016/j.ultras.2007.10.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/11/2007] [Revised: 09/10/2007] [Accepted: 10/10/2007] [Indexed: 05/25/2023]
Abstract
The biocompatible trisacryl particles (TMP) are made of a cross-linked acrylic copolymer. Their inherent acoustic properties, studied for a contrast agent application, have been previously demonstrated in a in vitro Couette device. To measure their acoustic behaviour under circulating blood conditions, the TMP backscatter enhancement was further evaluated on a home-made flow phantom at different TMP doses (0.12-15.6 mg/ml) suspended in aqueous and blood media, and in nude mice (aorta and B16 grafted melanoma). Integrated backscatter (IB) was measured by spectral analysis of the Doppler signals recorded from an ultrasound system (Aplio) combined with a 12-MHz probe. Doppler phantom experiments revealed a maximal IB of 17+/-0.88 dB and 7.5+/-0.7 dB in aqueous and blood media, respectively. IB measured on mice aorta, in pulsed Doppler mode, confirmed a constant maximal value of 7.29+/-1.72 dB over the first minutes after injection of a 7.8 mg/ml TMP suspension. Following the injection, a 60% enhancement of intratumoral vascularization detection was observed in power Doppler mode. A preliminary histological study revealed inert presence of some TMP in lungs 8 and 16 days after injection. Doppler phantom experiments on whole blood allowed to anticipate the in vivo acoustic behaviour. Both protocols demonstrated TMP effectiveness in significantly increasing Doppler signal intensity and intratumoral vascularization detection. However, it was also shown that blood conditions seemed to shadow the TMP contrast effect, as compared to in vitro observations. These results encourage further investigations on the specific TMP targeting and on their bio-distribution in the different tissues.
Collapse
Affiliation(s)
- Sonia Lavisse
- Universite de Paris-Sud, Imaging Department and UPRES EA 4040, Orsay F-91405, Institut Gustave Roussy, 39, Rue Camille Desmoulins, 94805 Villejuif Cedex, France
| | | | | | | | | | | | | | | |
Collapse
|
20
|
Salmaso S, Bersani S, Pennadam SS, Alexander C, Caliceti P. Avidin bioconjugate with a thermoresponsive polymer for biological and pharmaceutical applications. Int J Pharm 2007; 340:20-8. [PMID: 17449207 DOI: 10.1016/j.ijpharm.2007.03.010] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2007] [Revised: 03/05/2007] [Accepted: 03/06/2007] [Indexed: 11/20/2022]
Abstract
A thermoresponsive polymer, N-isopropylacrylamide-co-acrylamide (Mn 6 kDa) with a lower critical solution temperature (LCST) of 37 degrees C, was activated and conjugated to avidin to yield a derivative with 200 kDa molecular weight. Gel permeation analysis demonstrated that the new bioconjugate possessed an apparent size corresponding to a 220 kDa globular protein. Photon correlation spectroscopy and turbidometric studies showed that the bioconjugate underwent temperature dependent phase transitions. The protein-co-polymer bioconjugate displayed the same onset phase transition temperature (LCST) as the original synthetic co-polymer. Nevertheless, the aggregation profile of the bioconjugate shifted at higher temperature as compared to the original polymer. This indicated that the aggregation behaviour coil-to-globule transition of the co-polymer was modified by anchoring to the protein surface. Circular dichroism analysis showed that the co-polymer conjugation did not alter the protein tertiary structure tertiary the aromatic amino acid environment. The bioconjugate maintained 85+/-3% of native avidin affinity for biotin and biotin-Mab, and high affinity was maintained after three heating cycles. Pharmacokinetic studies demonstrated that the co-polymer bioconjugation increased the avidin residence time in the bloodstream. The distribution phase of avidin-co-polymer was longer than the native protein by a factor of 20. The co-polymer conjugation decreased by three-fold the distribution extent of avidin and reduced significantly its up-take to the liver.
Collapse
Affiliation(s)
- Stefano Salmaso
- Pharmaceutical Sciences Department, University of Padua, Via F. Marzolo 5, 35131 Padua, Italy
| | | | | | | | | |
Collapse
|
21
|
Yuan J, You Y, Lu X, Muzik O, Oupicky D, Peng F. Synthesis of Poly[APMA]-DOTA-64Cu conjugates for interventional radionuclide therapy of prostate cancer: assessment of intratumoral retention by micro-positron emission tomography. Mol Imaging 2007; 6:10-7. [PMID: 17311761] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/14/2023] Open
Abstract
To develop new radiopharmaceuticals for interventional radionuclide therapy of locally recurrent prostate cancer, poly[N-(3-aminopropyl)methacrylamide] [poly(APMA)] polymers were synthesized by free radical precipitation polymerization in acetone-dimethylsulfoxide using N,N'-azobis(isobutyronitrile) as the initiator. The polymers were characterized with nuclear magnetic resonance, size exclusion chromatography, and dynamic light scattering (M(n) = 2.40 x 10(4), M(w)/M(n) = 1.87). Subsequently, poly[APMA] was coupled with 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA) using 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride as an activator, followed by conjugation with (64)Cu radionuclide. Prolonged retention of poly[APMA]-DOTA-(64)Cu conjugates within the tumor tissues was demonstrated by micro-positron emission tomography at 24 hours following intra-tumoral injection of the conjugates to human prostate xenografts in mice. The data suggest that the poly[APMA]-DOTA-(64)Cu conjugates might be useful for interventional radionuclide therapy of locally recurrent prostate cancer in humans.
Collapse
Affiliation(s)
- Jianchao Yuan
- Department of Pediatrics, Wayne State University, Detroit, MI, USA
| | | | | | | | | | | |
Collapse
|
22
|
Mishra S, Bajpai R, Katare R, Bajpai AK. Preparation, characterization and microhardness study of semi interpenetrating polymer networks of polyvinyl alcohol and crosslinked polyacrylamide. J Mater Sci Mater Med 2006; 17:1305-13. [PMID: 17143762 DOI: 10.1007/s10856-006-0605-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/19/2005] [Accepted: 10/24/2005] [Indexed: 05/12/2023]
Abstract
Semi-IPNs based on polyvinyl alcohol (PVA) and crosslinked polyacrylamide (PAM) were prepared and characterized. Various compositions of semi-interpenetrating polymer networks (semi-IPNs) were prepared by varying concentrations of PVA, acrylamide (AM) and crosslinker N,N'-methylene bis acrylamide (MBA) in the feed mixtures and polymerized using a suitable redox system comprising of potassium persulphate and metabisulphite. The prepared semi-IPNs were characterized by fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and X-ray diffraction (XRD) methods. The prepared semi-IPNs were also investigated for microhardness measurements.
Collapse
Affiliation(s)
- Shefali Mishra
- Department of Postgraduate Studies and Research in Physics, Rani Durgavati University, Jabalpur 482 001, M.P., India
| | | | | | | |
Collapse
|
23
|
Affiliation(s)
- E B Margulis
- Department of Pharmaceutical Chemistry, State Medical University of Kazan, Kazan, Tatarstan, Russian Federation
| | | |
Collapse
|
24
|
Kabanova TV, Zhdanova ER, Moustafine RI. Characterization of Eudragit® E100/Carbomer 940P interpolyelectrolyte complexes using swellability measurements. J Control Release 2006; 116:e33-5. [PMID: 17718956 DOI: 10.1016/j.jconrel.2006.09.035] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Affiliation(s)
- T V Kabanova
- Department of Pharmaceutical Chemistry, State Medical University of Kazan, Kazan, Tatarstan, Russian Federation
| | | | | |
Collapse
|
25
|
Moustafine RI, Bobyleva OV. Design of new polymer carriers based of Eudragit® E PO/Eudragit® L100-55 interpolyelectrolyte complexes using swellability measurements. J Control Release 2006; 116:e35-6. [PMID: 17718957 DOI: 10.1016/j.jconrel.2006.09.036] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Affiliation(s)
- R I Moustafine
- Department of Pharmaceutical Chemistry, State Medical University of Kazan, Kazan, Tatarstan, Russian Federation
| | | |
Collapse
|
26
|
Trapani A, Laquintana V, Denora N, Lopedota A, Cutrignelli A, Franco M, Trapani G, Liso G. Eudragit RS 100 microparticles containing 2-hydroxypropyl-beta-cyclodextrin and glutathione: physicochemical characterization, drug release and transport studies. Eur J Pharm Sci 2006; 30:64-74. [PMID: 17118631 DOI: 10.1016/j.ejps.2006.10.003] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2006] [Revised: 09/27/2006] [Accepted: 10/16/2006] [Indexed: 11/22/2022]
Abstract
The aim of this study was to encapsulate glutathione (GSH) alone or in combination with hydroxypropyl-beta-cyclodextrin (HP-beta-CD) in Eudragit RS 100 microparticles (MPs), and to evaluate these novel delivery systems for oral administration of the considered tripeptide. The MPs were prepared by an O/O emulsion-solvent evaporation method according to a multilevel experimental design involving the volume of liquid paraffin, the HP-beta-CD amount, and the drug/polymer ratio as independent variables. The effects of these parameters on particle size, entrapment efficiency, and drug release were investigated. Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD) analysis and differential scanning calorimetry (DSC) studies were performed to evaluate possible interactions between GSH and Eudragit RS 100 polymer and to characterize the physical state of drug within the MPs. The release profiles of GSH from MPs were examined in vitro at pH 1.2, 6.8. and 7.4 using the USP III (BioDis) dissolution apparatus. In general, a slow and zero-order release of GSH from MPs at pH 1.2 occurred, while at higher pH values considerable amounts of glutathione disulfide (i.e., GSSG) were observed. The enzymatic stability and the intestinal permeability of some GSH-containing MPs were assessed by using pepsin, alpha-chymotrypsin, gamma-glutamyl-transpeptidase and everted frog intestinal sac methodology, respectively. The results suggest that GSH-loaded Eudragit RS 100 MPs containing HP-beta-CD represent a new sustained GSH delivery system useful for the oral administration of the examined tripeptide.
Collapse
Affiliation(s)
- Adriana Trapani
- Dipartimento Farmaco-Chimico, Facoltà di Farmacia, Università degli Studi di Bari, Via Orabona 4, 70125 Bari, Italy
| | | | | | | | | | | | | | | |
Collapse
|
27
|
Abstract
Prolonged release microparticles of clarithromycin (CL) were prepared using Eudragit RL 100 and RS 100 by spray-drying and casting-drying techniques. For the characterization of those microparticles, preparation yield, particle size distribution, X-ray diffraction, thermal behavior, active agent content and in vitro dissolution from the microparticles were performed. HPLC was used for the assay of clarithromycin and the assay method was validated. All the formulations obtained showed prolonged release when compared to pure clarithromycin. Microparticles prepared by spray-drying method had a slower release compared to those of casting-drying method. Spray-drying method seems to be a more suitable method to prepare microparticles for prolongation in release.
Collapse
Affiliation(s)
- Lüffi Genç
- Department of Pharmaceutical Technology, Anadolu University, Faculty of Pharmacy, 26470, Eskisehir Turkiye.
| | | | | |
Collapse
|
28
|
Zhang JX, Li XJ, Qiu LY, Li XH, Yan MQ, Zhu KJ. Indomethacin-loaded polymeric nanocarriers based on amphiphilic polyphosphazenes with poly (N-isopropylacrylamide) and ethyl tryptophan as side groups: Preparation, in vitro and in vivo evaluation. J Control Release 2006; 116:322-9. [PMID: 17109985 DOI: 10.1016/j.jconrel.2006.09.013] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2006] [Revised: 09/19/2006] [Accepted: 09/25/2006] [Indexed: 11/23/2022]
Abstract
The effects of copolymer composition, drug structure and initial drug feed on drug loading of polymeric micelles based on amphiphilic polyphosphazenes were investigated. It was found that the drug loading capacity of micelles based on this type of amphiphilic copolymers was mainly determined by copolymer composition and the chemical structure of drug. In addition to the compatibility between drug and micellar core, hydrogen bonding interaction between drug and hydrophilic corona may significantly influence drug loading as well. In vitro drug release in 0.1 M PBS (pH 7.4) suggested that indomethacin (IND) in the micelles was released through Fickian diffusion, and no significant difference in release rate was observed for micelles based on copolymers with various EtTrp content. Compared with in vitro IND release profile, in vivo pharmacokinetic study after subcutaneous administration provides a more sustained release behavior. Additionally, in comparison with free drug solution at the same dose, IND concentration in rat plasma showed a prolonged retention when the drug was delivered through polymeric micelles. In vivo pharmacodynamic study based on both carrageenan-induced acute and complete Freund's adjuvant-induced adjuvant arthritis model indicated that sustained therapeutic efficacy could be achieved through intraarticular injection of IND-loaded micelles. Most importantly, local delivery of IND can avoid the severe gastrointestinal stimulation, which was frequently associated with oral administration.
Collapse
Affiliation(s)
- Jian Xiang Zhang
- College of Pharmaceutical Sciences, Zhejiang University, Hangzhou 310031, China
| | | | | | | | | | | |
Collapse
|
29
|
Abstract
The objective of this study was to investigate the anion-controlled drug release mechanism through the cationic coating polymer Eudragit RS 30 D as a function of the anion attraction toward the polymer's quarternary ammonium group (QAG), anion valence, and film composition. The mechanism was investigated by dissolution testing, determination of chloride ion exchange using ion chromatography, plasticizer leaching by means of differential scanning calorimetry, and water uptake by Karl Fischer titration. All experiments were performed on coated theophylline micro tablets or isolated films of various compositions using 0.01 M sodium nitrate, sodium sulfate, disodium succinate, sodium acetate, and succinic acid as dissolution media. The mechanism of drug release involved an immediate penetration of dissolution medium into the polymer followed by an instant exchange of chloride against the medium's anion species at completely different rates compared with the drug release. Dependent on the attraction of the anion toward the QAGs, a water flux was induced by back and forth exchanging anions. Strong attraction (nitrate, sulfate) resulted in a low water flux while weak attraction resulted in a high flux (acetate, succinic acid). The water flux increased at increasing number of QAGs. Plasticizer acted as a diluent in respect of the number of QAGs, thus higher plasticizer concentrations led to lower drug release.
Collapse
Affiliation(s)
- Karl G Wagner
- University of Tuebingen, Institute of Pharmacy, Department of Pharmaceutical Technology, Tübingen, Germany.
| | | |
Collapse
|
30
|
Abstract
Polyacrylamide is a polymer of controllable molecular weight formed by the polymerization of acrylamide monomers available in one of three forms: solid (powder or micro beads), aqueous solution, or inverse emulsions (in water droplets coated with surfactant and suspended in mineral oil). Residual acrylamide monomer is likely an impurity in most Polyacrylamide preparations, ranging from <1 ppm to 600 ppm. Higher levels of acrylamide monomers are present in the solid form compared to the other two forms. Polyacrylamide is reportedly used in 110 cosmetic formulations, at concentrations ranging from 0.05% to 2.8%. Residual levels of acrylamide in Polyacrylamide can range from <.01% to 0.1%, although representative levels were reported at 0.02% to 0.03%. Because of the large sizes of Polyacrylamide polymers, they do not penetrate the skin. Polyacrylamide itself is not significantly toxic. For example, an acute oral toxicity study of Polyacrylamide in rats reported that a single maximum oral dose of 4.0 g/kg body weight was tolerated. In subchronic oral toxicity studies, rats and dogs treated with Polyacrylamide at doses up to 464 mg/kg body weight showed no signs of toxicity. Several 2-year chronic oral toxicity studies in rats and dogs fed diets containing up to 5% Polyacrylamide had no significant adverse effects. Polyacrylamide was not an ocular irritant in animal tests. No compound-related lesions were noted in a three-generation reproductive study in which rats were fed 500 or 2000 ppm Polyacrylamide in their diet. Polyacrylamide was not carcinogenic in several chronic animal studies. Human cutaneous tolerance tests performed to evaluate the irritation of 5% (w/w) Polyacrylamide indicated that the compound was well tolerated. Acrylamide monomer residues do penetrate the skin. Acrylamide tested in a two-generation reproductive study at concentrations up to 5 mg/kg day(- 1) in drinking water, was associated with prenatal lethality at the highest dose, with evidence of parental toxicity. The no adverse effects level was close to the 0.5 mg/kg day(- 1) dose. Acrylamide tested in a National Toxicology Program (NTP) reproductive and neurotoxicity study at 3, 10, and 30 ppm produced no developmental or female reproductive toxicity. However, impaired fertility in males was observed, as well as minimal neurotoxic effects. Acrylamide neurotoxicity occurs in both the central and peripheral nervous systems, likely through microtubule disruption, which has been suggested as a possible mechanism for genotoxic effects of acrylamide in mammalian systems. Acrylamide was genotoxic in mammalian in vitro and in vivo assays. Acrylamide was a tumor initiator, but not an initiator/promoter, in two different mouse strains at a total dose of 300 mg/kg (6 doses over 2 weeks) resulting in increased lung adenomas and carcinomas without promotion. Acrylamide was tested in two chronic bioassays using rats. In one study, increased incidence of mammary gland tumors, glial cell tumors, thyroid gland follicular tumors, oral tissue tumors, uterine tumors and clitoral gland tumors were noted in female rats. In male rats, the number of tumors in the central nervous system (CNS), thyroid gland, and scrotum were increased with acrylamide exposure. In the second study, using higher doses and a larger number of female rats, glial cell tumors were not increased, nor was there an increase in mammary gland, oral tissue, clitoral gland, or uterine tumors. Tumors of the scrotum in male rats were confirmed, as were the thyroid gland follicular tumors in males and females. Taken together, there was a dose-dependent, but not statistically significant, increase in the number of astrocytomas. Different human lifetime cancer risk predictions have resulted, varying over three orders of magnitude from 2 x 10(- 3) to 1.9 x 10(- 6). In the European Union, acrylamide has been limited to 0.1 ppm for leave-on cosmetic products and 0.5 ppm for other cosmetic products. An Australian risk assessment suggested negligible health risks from acrylamide in cosmetics. The Cosmetic Ingredient Review (CIR) Expert Panel acknowledged that acrylamide is a demonstrated neurotoxin in humans and a carcinogen in animal tests, but that neurotoxic levels could not be attained by use of cosmetics. Although there are mechanisms of action of acrylamide that have been proposed for tumor types seen in rat studies that suggest they may be unique to the rat, the Panel was not convinced that these results could be disregarded as a species-specific finding with no relevance to human health and safety. Based on the genotoxicity and carcinogenicity data, the Panel does not believe that acrylamide is a genotoxic carcinogen in the usual manner and that several of the risk assessment approaches have overestimated the human cancer risk. The Panel did conclude, however, that it was appropriate to limit acrylamide levels to 5 ppm in cosmetic formulations.
Collapse
|
31
|
Alvarez-Lorenzo C, Concheiro A, Dubovik AS, Grinberg NV, Burova TV, Grinberg VY. Temperature-sensitive chitosan-poly(N-isopropylacrylamide) interpenetrated networks with enhanced loading capacity and controlled release properties. J Control Release 2005; 102:629-41. [PMID: 15681085 DOI: 10.1016/j.jconrel.2004.10.021] [Citation(s) in RCA: 119] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2004] [Accepted: 10/18/2004] [Indexed: 11/30/2022]
Abstract
Interpenetrated polymer networks (IPN) of poly(N-isopropylacrylamide) (PNIPA) and chitosan (two grades) were prepared by free radical polymerisation and cross-linking of PNIPA (700 mM) with bis(acrylamide) (20 mM) in chitosan solutions (1.5 wt.% in acetic acid), and subsequent immersion in glutaraldehyde solutions (0 to 0.7 vol.%) to post-cross-link the chitosan. The amount of chitosan that remained in the IPNs, after washing, was proportional to the glutaraldehyde concentration used in the post-cross-linking step; being only 50% of the theoretical when the post-cross-linking was omitted (semi-IPN). The temperature-induced phase transitions of the IPNs were followed by the changes in the swelling degree and in the thermodynamic parameters (temperature, enthalpy, heat capacity, and width of the transition), which were evaluated using high-sensitivity differential scanning calorimetry (HS-DSC). An increase in the post-cross-linking degree of chitosan caused a decrease in the enthalpy of the transition, and in the absolute value of the transition heat capacity increment (delta(t)C(p)), as well as a broadening of the heat capacity peak. This behaviour is a consequence of the subdivision, in the IPNs, of the PNIPA network in microdomains, some regions of which (surface or outer) cannot be involved in the transitions. On the other hand, changes in pH from 8 to 3 only increased the transition temperature from about 32 to 34 degrees C, despite the considerable modification that this caused in the ionisation degree of chitosan. The PNIPA/chitosan IPNs had a notably greater affinity for diclofenac than the pure PNIPA hydrogel and were able to sustain the drug release for more than 8 h in 0.9% NaCl solutions or pH 8 phosphate buffer. The IPNs with lower chitosan post-cross-linking degree showed the higher temperature-sensitive release patterns. In contrast, the temperature did not significantly affect the release rate from the most cross-linked IPNs, in which the PNIPA microdomains are smaller and the volume phase transitions are less sharper. Therefore, PNIPA microdomains play an important role in controlling the release process. In summary, the interpenetration of networks with complementary properties, such as those made with PNIPA and chitosan, make it possible to develop drug delivery systems with improved drug loading capacity (owing to chitosan) and sustained release behaviour (owing to PNIPA).
Collapse
Affiliation(s)
- Carmen Alvarez-Lorenzo
- Departamento de Farmacia y Tecnología Farmacéutica, Facultad de Farmacia, Universidad de Santiago de Compostela, 15782-Santiago de Compostela, Spain.
| | | | | | | | | | | |
Collapse
|
32
|
Lopez VC, Hadgraft J, Snowden MJ. The use of colloidal microgels as a (trans)dermal drug delivery system. Int J Pharm 2005; 292:137-47. [PMID: 15725560 DOI: 10.1016/j.ijpharm.2004.11.040] [Citation(s) in RCA: 119] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2004] [Revised: 11/16/2004] [Accepted: 11/24/2004] [Indexed: 10/25/2022]
Abstract
A co-polymer of poly(N-isopropylacrylamide) (85%) co-butyl acrylate (10%) co-methacrylic acid (5%) (NIPAM/BA/MAA) (85/10/5) microgel was synthesised and investigated as a potential pH and temperature sensitive transdermal delivery device. Three compounds having different octanol/water partition coefficients and solubilities were incorporated into the microgel, namely: salicylamide (SA), methyl paraben (MP) and propyl paraben (PP). Physico-chemical characterisation of these microgel-drug complexes showed that microgels incorporating MP and SA have smaller volumes after changing environmental pH or temperature when compared with the co-polymer NIPAM/BA/MAA (85/10/5) alone. This reduction in volume could be attributed to the incorporation of the compounds into the microgel particles, having a shielding effect on the charged groups present within the network. Diffusion studies, across human skin, were performed at 305K in the range of pH 3-7 for saturated solutions of SA, MP and PP, and for microgel particles incorporating the three compounds. The transport rate for these microgels incorporating MP was reduced by 2/3-fold compared to the saturated solution, by one order of magnitude for PP, meanwhile the transport rate for these microgels incorporating SA is the same order of magnitude as that for the corresponding saturated solutions. Transdermal release studies of the saturated colloidal dispersions indicated that pH control of the drug release was marginal. The incorporation of compounds into the pH/temperature sensitive co-polymer NIPAM/BA/MAA (85/10/5) and the subsequent release depends on the octanol/water partition coefficient and solubility of the respective compound.
Collapse
Affiliation(s)
- V Castro Lopez
- Medway Sciences, University of Greenwich at Medway, Chatham Maritime, Kent ME4 4TB, UK
| | | | | |
Collapse
|
33
|
Leitner VM, Guggi D, Bernkop-Schnürch A. Thiomers in noninvasive polypeptide delivery: in vitro and in vivo characterization of a polycarbophil-cysteine/glutathione gel formulation for human growth hormone. J Pharm Sci 2005; 93:1682-91. [PMID: 15176058 DOI: 10.1002/jps.20069] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
This study was aimed at investigating the potential of a new polycarbophil-cysteine (PCP-Cys)/glutathione (GSH) gel formulation to enhance the permeation of the model drug human growth hormone (hGH) across nasal mucosa in vitro and in vivo. The aqueous nasal gel contained PCP-Cys, GSH, and hGH in a final concentration of 0.3%, 0.5%, and 0.6% (m/v), respectively. In vitro permeation studies were performed in Ussing chambers on freshly excised bovine nasal mucosa using fluorescence-labeled dextran (molecular mass: 4.3 kDa; FD-4) and hGH (FITC-hGH). The release profile of FITC-hGH from the gel formulation and an unmodified PCP control formulation was determined. Furthermore, in vivo studies in rats were performed comparing the PCP-Cys/GSH/hGH gel with PCP/hGH control gel and physiological saline. The permeation of FD-4 and FITC-hGH across the nasal mucosa was improved two-fold and three-fold, respectively, in the presence of PCP-Cys/GSH. The PCP-Cys/GSH/hGH gel and the PCP/hGH control gel showed the same biphasic and matrix-controlled drug release. The nasal administration of the PCP-Cys/GSH/hGH gel formulation to rats resulted in a significantly increased and prolonged hGH plasma concentration-time profile versus unmodified PCP gel and physiological saline. According to these results, PCP-Cys gels might represent a promising new strategy for systemic nasal polypeptide delivery.
Collapse
Affiliation(s)
- Verena M Leitner
- Institute of Pharmaceutical Technology and Biopharmaceutics, Center of Pharmacy, University of Vienna, Althanstr. 14, A-1090 Vienna, Austria
| | | | | |
Collapse
|
34
|
Barreiro-Iglesias R, Bromberg L, Temchenko M, Hatton TA, Concheiro A, Alvarez-Lorenzo C. Solubilization and stabilization of camptothecin in micellar solutions of pluronic-g-poly(acrylic acid) copolymers. J Control Release 2005; 97:537-49. [PMID: 15212885 DOI: 10.1016/j.jconrel.2004.04.007] [Citation(s) in RCA: 94] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2004] [Accepted: 04/13/2004] [Indexed: 11/25/2022]
Abstract
The capability of a family of copolymers comprising Pluronic (PEO-PPO-PEO) surfactants covalently conjugated with poly(acrylic acid) (Pluronic-PAA) to enhance the aqueous solubility and stability of the lactone form of camptothecin (CPT) was studied. The unprotected lactone form of CPT, which possesses cytotoxic activity, is rapidly converted to the ring-opened carboxylate form under physiological conditions. Firstly, surfactant properties such as critical micellization concentration (CMC) of Pluronic-PAA copolymers were characterized. Then, the equilibrium solubility partitioning and hydrolysis of the lactone form of CPT in the presence of Pluronic-PAA in water and in human serum were analyzed. CPT solubility in polymer micellar solutions was ca. 3- to 4-fold higher than that in water at pH 5. The amount of CPT solubilized per PPO was considerably greater in the Pluronic-PAA solutions than in the parent Pluronic solution, which suggests that the drug is not only solubilized by the hydrophobic cores and also by the hydrophilic POE-PAA shells of the micelles. The equilibrium partition coefficient of the CPT lactone between Pluronic-PAA solutions and water exceeded (2-3) x 10(3). The complete solubilization of CPT and the absence of chemical interactions between CPT and Pluronic-PAA were confirmed by modulated temperature differential scanning calorimetry (MTDSC), infrared spectroscopy, and X-ray diffraction of films. The loading of CPT into the Pluronic-PAA micelles was able to prevent the hydrolysis of the lactone group of the drug for 2 h at pH 8 in water. When compared to the unprotected CPT, the kinetics of the CPT hydrolysis in human serum was about 10-fold slower in the Pluronic-PAA formulations.
Collapse
Affiliation(s)
- Rafael Barreiro-Iglesias
- Departamento de Farmacia y Tecnología Farmacéutica, Facultad de Farmacia, Universidad de Santiago de Compostela, Santiago de Compostela 15872, Spain
| | | | | | | | | | | |
Collapse
|
35
|
Fujimori J, Yoshihashi Y, Yonemochi E, Terada K. Application of Eudragit RS to thermo-sensitive drug delivery systems. J Control Release 2005; 102:49-57. [PMID: 15653133 DOI: 10.1016/j.jconrel.2004.09.027] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2004] [Accepted: 09/17/2004] [Indexed: 11/18/2022]
Abstract
The Eudragit RS and polyethylene glycol 400 (PEG 400) blend polymer (EPG) membranes were prepared by the solvent casting method to pioneer a novel application of Eudragit RS to a thermo-sensitive material. The EPG membranes containing 2.5-10% PEG 400 (2.5-10% EPG) showed the glass transition temperatures (Tgs) around the body temperature (32-42 degrees C). Drug permeation studies through the EPG membranes were carried out using acetaminophen (AAP) and aminopyrine (AMP) as the model drugs. The permeability of AAP and AMP through the EPG membranes has been shown to be a discontinuous function of temperature, that is, their permeability increased steeply above the Tg of the membranes. The amount of AMP permeated at 42 degrees C was nearly eight times as much as that at 36 degrees C. Arrhenius plots of the steady-state permeability coefficient (P) of AAP indicated two straight lines that intersect at the Tg of the 10% EPG membrane. In the water uptake study for the 10% EPG membrane, the degree of the swelling for the membrane tended to increase with increasing temperature above the Tg of the membrane. The thermo-sensitive permeation mechanism for the EPG membranes might be based on the structure change of the membranes caused by the glass transition, so that the membranes could absorb more water. Considering the high biological safety of Eudragit RS and PEG 400, the EPG membranes might be used to develop a novel thermo-sensitive drug delivery system.
Collapse
Affiliation(s)
- Junya Fujimori
- Faculty of Pharmaceutical Sciences, Toho University, 2-2-1 Miyama, Funabashi, Chiba 274-8510, Japan.
| | | | | | | |
Collapse
|
36
|
Ubrich N, Schmidt C, Bodmeier R, Hoffman M, Maincent P. Oral evaluation in rabbits of cyclosporin-loaded Eudragit RS or RL nanoparticles. Int J Pharm 2005; 288:169-75. [PMID: 15607269 DOI: 10.1016/j.ijpharm.2004.09.019] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2004] [Revised: 09/07/2004] [Accepted: 09/10/2004] [Indexed: 11/16/2022]
Abstract
The hydrophobic cyclic undecapeptide cyclosporin A (CyA) used in the prevention of graft rejection and in the treatment of autoimmune diseases was encapsulated by nanoprecipitation within non-biodegradable polymeric nanoparticles. The effect of polymers (Eudragit RS or RL) and additives within the alcoholic phase (fatty acid esters and polyoxyethylated castor oil) on the size, zeta potential and the encapsulation efficiency of the nanoparticles was investigated. The mean diameter of the various CyA nanoparticles ranged from 170 to 310 nm. The size as well as the zeta potential increased by adding fatty acid ester and polyoxyethylated castor oil within the organic phase. No significant differences in surface potential were observed for all formulations tested. Probably due to the very low water solubility of the drug, high encapsulation efficiencies were observed in a range from 70 to 85%. The oral absorption of CyA from these polymeric nanoparticles was studied in rabbits and compared to that of Neoral capsule. Based on comparison of the area under the blood concentration-time curve values, the relative bioavailability of CyA from each nanoparticulate formulation ranged from 20 to 35%.
Collapse
Affiliation(s)
- N Ubrich
- Laboratoire de Pharmacie Galénique, EA 3452, Faculté de Pharmacie, 5, rue Albert Lebrun, B.P. 403, 54001 Nancy Cedex, France.
| | | | | | | | | |
Collapse
|
37
|
Meyer-Lueckel H, Mueller J, Paris S, Hummel M, Kielbassa AM. [The penetration of various adhesives into early enamel lesions in vitro]. Schweiz Monatsschr Zahnmed 2005; 115:316-23. [PMID: 15901039] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
The aim of the present study was to evaluate the penetration depth (PD) and the thickness of the oxygen inhibition layer (OIL) of a fissure sealant (Helioseal, Vivadent) and various adhesives (Heliobond, Excite, Vivadent; Resulcin, Merz; Solobond M, Voco; Prompt L-Pop, 3M-Espe) applied to enamel lesions in vitro. From 27 bovine teeth 54 enamel specimens were prepared and covered with nail varnish (control) thus obtaining three windows for treatment. After demineralisation (pH 5.0, 14 d) two of the windows were etched with phosphoric acid (20%, 5 s), whereas the third area served as control. The specimens were divided randomly into six groups (n = 9) and the respective adhesive was applied (90 s), either once or twice. Light-curing followed each application. Enamel slabs (perpendicular to the surface) were cut and studied after infiltration with a fluorescent low-viscous resin using confocal microscopy (CLSM). The image of the lesion was divided into two areas with different grey values. Lesion depths were calculated (ImageJ) from the surface to that point in the lesion where the grey value clearly changed to a darker grey value. The zone with the darker grey values marked the front of demineralisation. Mean lesion depths (+/- SD) after demineralisation were measured at 105 (+/- 21) microm. After single application, Resulcin [89 (+/- 22)%] and Helioseal [98 (+/- 6)%] had almost completely penetrated the lesion. Heliobond [126 (+/- 33)%] and Excite [184 (+/- 40)%] penetrated even deeper than the defined lesion. For Excite double application decreased the OIL significantly (p = 0.03; adjusted paired t-test). Adhesives are capable to penetrate artificial initial enamel lesions completely. Follow-up studies are needed to confirm this effect for natural lesions.
Collapse
Affiliation(s)
- H Meyer-Lueckel
- Poliklinik für Zahnerhaltungskunde und Parodontologie, Klinik und Polikliniken für Zahn-, Mund- und Kieferheilkunde, Campus Benjamin Franklin, Charité - Universitätsmedizin Berlin
| | | | | | | | | |
Collapse
|
38
|
Chua GC, Wilsher M, Young MPA, Manyonda I, Morgan R, Belli AM. Comparison of particle penetration with non-spherical polyvinyl alcohol versus trisacryl gelatin microspheres in women undergoing premyomectomy uterine artery embolization. Clin Radiol 2005; 60:116-22. [PMID: 15642302 DOI: 10.1016/j.crad.2004.08.008] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2004] [Revised: 08/11/2004] [Accepted: 08/11/2004] [Indexed: 10/25/2022]
Abstract
AIM The purpose of this study was to compare the depth of vascular penetration of non-spherical polyvinyl alcohol (PVA) versus trisacryl gelatin microspheres (MS) in women undergoing uterine artery embolization (UAE) immediately before transabdominal myomectomy. MATERIALS AND METHODS A total of 17 patients who had been referred for embolization before myomectomy underwent bilateral uterine artery embolization using either 355-500 microm PVA (group A) or 700-900 microm MS (group B). The depth of penetration of the particles was assessed by identifying their presence and location in the resected specimen. RESULTS Of the 17 women enrolled in this study, 10 were in group A and 6 in group B. One woman underwent embolization using both types of particle and was excluded from the analysis. Embolic particles were significantly (p = 0.048) more frequently located within the fibroid (4/6, 67%) in Group B than Group A (1/10, 10%). Particles were also identified in the perifibroid tissues in 4/6 (67%) in Group B and 4/10 (40%) in Group A, with no statistical difference. There were no procedural complications. CONCLUSION MS particles (700-900 microm) penetrate significantly deeper into leiomyomata compared with non-spherical PVA (355-500 microm). MS may therefore confer advantages in UAE, as they may more specifically target the fibroid, allowing an earlier end-point to embolization and minimizing ischaemic damage to normal myometrium and ovaries.
Collapse
Affiliation(s)
- G C Chua
- Department of Radiology, St George's Hospital, London, UK
| | | | | | | | | | | |
Collapse
|
39
|
Jimenez-Kairuz AF, Llabot JM, Allemandi DA, Manzo RH. Swellable drug-polyelectrolyte matrices (SDPM). Int J Pharm 2005; 288:87-99. [PMID: 15607261 DOI: 10.1016/j.ijpharm.2004.09.014] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2004] [Revised: 09/21/2004] [Accepted: 09/21/2004] [Indexed: 12/01/2022]
Abstract
The objective of the study is to develop and characterize the delivery properties of swellable drug-polyelectrolyte matrices (SDPM). Solid complexes (C-D)X of carbomer (C) neutralized with different proportions of model basic drugs (D), in which D is atenolol, lidocaine, and metoclopramide, and X=25, 50, 75 and 100 mol of D per 100 equivalents of carboxylic groups of C, were prepared and characterized by DSC-TG, IR, and X-ray diffraction studies. Mechanistic studies with hydrophilic and hydrophobic basic drugs were conducted to explore the drug release patterns of SDPM. Besides, release and up-take studies were carried out in water and NaCl solution to examine the influence of ionic effects. The authors concluded that drugs can be loaded in a high proportion on to the polymer and therefore the resulting (C-D) material could be diluted with other polymers to modulate delivery properties of SDPM. Matrices of atenolol and lidocaine exhibited robust delivery properties with regard to change in proportion of loading D.
Collapse
Affiliation(s)
- Alvaro Federico Jimenez-Kairuz
- Departamento de Farmacia, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Edificio Ciencias 2, Cuidad Universitaria, 5000 Córdoba, Argentina.
| | | | | | | |
Collapse
|
40
|
Kurkuri MD, Aminabhavi TM. Poly(vinyl alcohol) and poly(acrylic acid) sequential interpenetrating network pH-sensitive microspheres for the delivery of diclofenac sodium to the intestine. J Control Release 2004; 96:9-20. [PMID: 15063025 DOI: 10.1016/j.jconrel.2003.12.025] [Citation(s) in RCA: 131] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2003] [Accepted: 12/18/2003] [Indexed: 11/30/2022]
Abstract
Sequential interpenetrating network (IPN) of poly(vinyl alcohol) (PVA) and poly(acrylic acid) (PAA) were prepared and crosslinked with glutaraldehyde (GA) to form pH-sensitive microspheres by the water-in-oil (w/o) emulsification method. Microspheres were used to deliver a model anti-inflammatory drug, diclofenac sodium (DS), to the intestine. The formed IPN was analyzed by Fourier transform infrared spectroscopy (FTIR). Differential scanning calorimetry (DSC) and X-ray diffraction (XRD) analyses were done on the drug-loaded microspheres to confirm the polymorphism of DS. Results indicated a molecular level dispersion of DS in the IPN. Microspheres formed were spherical with the smooth surfaces as evidenced by scanning electron microscopy (SEM). Particle size and size distribution was studied using laser light diffraction particle size analyzer. Particle size analysis was also done by optical microscope for the selected microspheres; the change in diameter of the microspheres when soaked in different media at different time intervals was measured by optical microscope. Microspheres showed a pulsatile swelling behavior when the pH of the swelling media was changed. The swelling data were fitted to an empirical equation to understand the phenomenon of water transport as well as to calculate the diffusion coefficient (D). Values of D in acidic media were lower than those found in basic media. The values of D decrease with increasing crosslinking of the matrix. In-vitro release studies have been performed in 1.2 and 7.4 pH media to simulate gastric and intestinal conditions. The results indicated a dependence on the pH of the release media, extent of crosslinking and the amount of drug loading.
Collapse
Affiliation(s)
- Mahaveer D Kurkuri
- Drug Delivery Division, Center of Excellence in Polymer Science, Karnatak University, Dharwad 580 003, India
| | | |
Collapse
|
41
|
El-Samaligy MS, Yahia SA, Basalious EB. Formulation and evaluation of diclofenac sodium buccoadhesive discs. Int J Pharm 2004; 286:27-39. [PMID: 15501000 DOI: 10.1016/j.ijpharm.2004.07.033] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2004] [Revised: 06/09/2004] [Accepted: 07/30/2004] [Indexed: 10/26/2022]
Abstract
Twenty diclofenac sodium buccoadhesive discs containing Cp974p, polycarbophil, PEO, SCMC-medium viscosity (SCMC-MV), SCMC-ultrahigh viscosity (SCMC-UHV) or their combinations were prepared. These buccoadhesive discs were evaluated for release pattern, swelling capacity, surface pH, mucoadhesion performance, and in vitro permeation of diclofenac sodium through buccal membranes. In vivo testing of mucoadhesion time, strength of adhesion, irritation, bitterness due to drug swallowing and disc disintegration in the buccal cavity were also performed. Drug bioavailability of a selected diclofenac sodium buccoadhesive product was then compared with that of Voltarin 100 SR tablet. The percentage relative bioavailability of diclofenac sodium from the selected buccoadhesive disc 50 mg was found to be 141.31%.
Collapse
Affiliation(s)
- M S El-Samaligy
- Department of Pharmaceutics, Faculty of Pharmacy, Cairo University, Kasr El-aini Street, Cairo, Egypt.
| | | | | |
Collapse
|
42
|
Tatavarti AS, Mehta KA, Augsburger LL, Hoag SW. Influence of methacrylic and acrylic acid polymers on the release performance of weakly basic drugs from sustained release hydrophilic matrices. J Pharm Sci 2004; 93:2319-31. [PMID: 15295792 DOI: 10.1002/jps.20129] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Weakly basic drugs and their salts exhibit a drop in aqueous solubility at high pH conditions, which can result in low and incomplete release of these drugs from sustained release formulations. The objective of this study is to modulate matrix microenvironmental pH by incorporation of acidic polymers and thus enhance the local solubility and release of basic drugs in high pH environment. Two weakly basic drugs, papaverine hydrochloride and verapamil hydrochloride with widely different pKa and aqueous solubilities at the pH of interest (6.8), were investigated for their release from hydrophilic matrices and the effect of a methacrylic (Eudragit L100-55) and an acrylic acid polymer (Carbopol 71G), were studied. For papaverine HCl, release increased with an increase in the levels of the acidic polymer used. Direct measurement of matrix pH using microelectrodes illustrated that the mechanism of release enhancement was based on modulation of microenvironmental pH. For verapamil HCl, incorporation of L100-55 resulted in release retardation due to an interaction between the anionic polymer and the cationic drug and the extent of retardation increased with an increase in the polymer level. The interaction product was characterized by NIR, FT-IR, and MTDSC techniques. Verapamil HCl release from Carbopol 71G based matrix tablets was higher than that from conventional hydroxypropyl methylcellulose (HPMC) based matrices, without any incorporated acidic additives.
Collapse
Affiliation(s)
- Aditya S Tatavarti
- School of Pharmacy, University of Maryland, Baltimore, 20 N. Pine Street, Baltimore, Maryland 21201, USA
| | | | | | | |
Collapse
|
43
|
Pearnchob N, Bodmeier R. Dry polymer powder coating and comparison with conventional liquid-based coatings for Eudragit) RS, ethylcellulose and shellac. Eur J Pharm Biopharm 2004; 56:363-9. [PMID: 14602178 DOI: 10.1016/s0939-6411(03)00121-8] [Citation(s) in RCA: 72] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Drug-layered pellets were coated with micronized polymer powders (Eudragit) RS, ethylcellulose, and shellac) by a dry powder coating technique as an alternative to organic- and aqueous-based coatings (Eudragit) RS 30D, Aquacoat) ECD) were investigated. High plasticizer concentrations (40%) and a thermal after-treatment (curing) were necessary for the coalescence of the polymer particles and good film formation. Ethylcellulose required a higher curing temperature and time than Eudragit) RS because of its higher glass transition temperature (133 versus 58 degrees C). A smaller polymer particle size also promoted film formation. In general, pellets coated with polymer powders required higher coating levels to obtain similar drug release patterns as pellets coated with organic polymer solutions and aqueous polymer dispersions.
Collapse
|
44
|
Coughlan DC, Quilty FP, Corrigan OI. Effect of drug physicochemical properties on swelling/deswelling kinetics and pulsatile drug release from thermoresponsive poly(N-isopropylacrylamide) hydrogels. J Control Release 2004; 98:97-114. [PMID: 15245893 DOI: 10.1016/j.jconrel.2004.04.014] [Citation(s) in RCA: 178] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2004] [Accepted: 04/27/2004] [Indexed: 11/26/2022]
Abstract
The effect of drug physicochemical properties on swelling/deswelling kinetics and pulsatile drug release from a thermoresponsive hydrogel was examined. Hydrogels were loaded with drug and thermally triggered swelling/deswelling and release experiments were performed. Two series of drugs of contrasting hydrophilicity and varying physicochemical properties were examined. Benzoic acid (BA), its methyl and propyl esters, and diltiazem base were used as model hydrophobic drugs. Sodium benzoate (NaB), diltiazem HCl (DHCl), vitamin B12 (VB12) and various dextrans (MW 4300, 10,200, 42,000, 68,800) were used as model hydrophilic agents of increasing size. The hydrogel swelling rate was slowed by the presence of the hydrophobic drugs and this decreased rate was solubility dependant for the benzoates. The hydrophilic series increased the rate of swelling compared to the unloaded system. In all cases, the magnitude and rate of hydrogel contraction were proportional to the extent of swelling prior to temperature switch. Drug release was by diffusion below the lower critical solution temperature (LCST), while a solubility-dependent drug pulse release on temperature switch was observed for the hydrophobic series. Effectiveness of thermal control of hydrophobic drug release increased with increasing solubility. The hydrophilic series produced a molecular size-dependent drug pulse on temperature switch above the LCST. Pulsatile on-off drug release was shown with DHCl, VB12 and the various dextrans. Drug solubility, size and chemical nature were shown to be of particular importance in the control of hydrogel swelling and drug release from thermosensitive hydrogels.
Collapse
Affiliation(s)
- D C Coughlan
- School of Pharmacy, Trinity College, Dublin, 2, Ireland
| | | | | |
Collapse
|
45
|
Van Landingham CB, Lawrence GA, Shipp AM. Estimates of lifetime-absorbed daily doses from the use of personal-care products containing polyacrylamide: a Monte Carlo analysis. Risk Anal 2004; 24:603-619. [PMID: 15209933 DOI: 10.1111/j.0272-4332.2004.00462.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Estimates of the lifetime-absorbed daily dose (LADD) of acrylamide resulting from use of representative personal-care products containing polyacrylamides have been developed. All of the parameters that determine the amount of acrylamide absorbed by an individual vary from one individual to another. Moreover, for some parameters there is uncertainty as to which is the correct or representative value from a range of values. Consequently, the parameters used in the estimation of the LADD of acrylamide from usage of a particular product type (e.g., deodorant, makeup, etc.) were represented by distributions evaluated using Monte Carlo analyses.((1-4)) From these data, distributions of values for key parameters, such as the amount of acrylamide in polyacrylamide, absorption fraction, etc., were defined and used to provide a distribution of LADDs for each personal-care product. The estimated total acrylamide LADD (across all products) for males and females at the median, mean, and 95th percentile of the distribution of individual LADD values were 4.7 x 10(-8), 2.3 x 10(-7), and 7.3 x 10(-7) mg/kg/day for females and 3.6 x 10(-8), 1.7 x 10(-7), and 5.4 x 10(-7) mg/kg/day for males. The ratio of the LADDs to risk-specific dose corresponding to a target risk level of 1 x 10(-5), the acceptable risk level for this investigation, derived using approaches typically used by the FDA, the USEPA, and proposed for use by the European Union (EU) were also calculated. All ratios were well below 1, indicating that all the extra lifetime cancer risk from the use of polyacrylamide-containing personal-care products, in the manner assumed in this assessment, are well below acceptable levels. Even if it were assumed that an individual used all of the products together, the estimated LADD would still provide a dose that was well below the acceptable risk levels.
Collapse
|
46
|
Smart JD, Riley RG, Tsibouklis J, Young SA, Hampson FC, Davis JA, Kelly G, Dettmar PW, Wilber WR. The retention of 14C-labelled poly(acrylic acids) on gastric and oesophageal mucosa: an in vitro study. Eur J Pharm Sci 2004; 20:83-90. [PMID: 13678796 DOI: 10.1016/s0928-0987(03)00175-1] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Polymers that bind from solution onto gastric mucosa can be used either as a means of facilitating localised drug delivery, or can act as therapeutic agents in their own right (e.g. by forming a protective layer or by inhibiting enzymes). In our previous study [Int. J. Pharm. 236 (2002) 87], the binding and retention of labelled poly(acrylic acid)s on sections of gastric mucosa from pigs was evaluated using 'dynamic flow' conditions and a high molecular weight poly(acrylic acid) was found to bind most avidly. In the current study, 3% solutions of 'low', 'high' and 'ultra high' molecular weight polymers were evaluated in the 'dynamic flow' model for their ability to bind to tissues from the fundic and pyloric regions of the stomach and the oesophagus of pigs. All the polymers tested were retained on each mucosa for extended periods; the high and ultra high molecular weight polymers showed the greatest retention. Examination of the kinetics of polymer elution suggested that two fractions exist, 'bound' and 'unbound' polymer, showing differing retention profiles. The high molecular weight polymer showed the greatest retention on pyloric tissue, particularly on the upper sections. The retention of the ultra high and high molecular weight polymer was similar on the fundic and oesophageal mucosa, and the distribution was even across the tissue. It was concluded that poly(acrylic acid) binding from solution presents a therapeutic opportunity, and the differences in binding and retention of the polymers on the different mucosae could present an opportunity for targeting.
Collapse
Affiliation(s)
- John D Smart
- Biomaterials and Drug Delivery Research Unit, School of Pharmacy and Biomedical Sciences, University of Portsmouth, St Michael's Building, White Swan Road, Portsmouth, PO1 2DT, UK.
| | | | | | | | | | | | | | | | | |
Collapse
|
47
|
Omari DM, Sallam A, Abd-Elbary A, El-Samaligy M. Lactic acid-induced modifications in films of Eudragit RL and RS aqueous dispersions. Int J Pharm 2004; 274:85-96. [PMID: 15072785 DOI: 10.1016/j.ijpharm.2004.01.004] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2003] [Revised: 12/16/2003] [Accepted: 01/06/2004] [Indexed: 11/23/2022]
Abstract
Eudragit RL (ERL) and RS (ERS) are polymethacrylate co-polymers, used in film coating of sustained release dosage forms, possessing some hydrophilic properties due to the presence of quaternary ammonium groups (QAG), where ERL contains more of such groups, hence more permeable, than ERS. However, because these groups ionize in solution, they undergo electrostatic interaction with negatively charged species. This phenomenon was utilized in this study to introduce modification in the film properties of ERL and ERS by interaction with lactic acid (LA). Thermal and mechanical analyses were carried out on polymeric free films. DSC showed a shift in Tg of the film while 1H NMR spectroscopy revealed a significant deshielding in the peak of QAGs protons after interaction with LA. Stress-strain test showed an increase in three mechanical parameters of the new film (containing LA): tensile strength to modulus ratio, relative surface energy and toughness index, indicating an enhancement in the mechanical stress resistance. Tablets coated with LA-containing films showed an increase in the release rate and extent and good stability upon aging, compared to those coated with the original film.
Collapse
Affiliation(s)
- Derar M Omari
- Arab Pharm. Manuf. (APM) Co., P.O. Box 961997, Amman 11196, Sult, Jordan.
| | | | | | | |
Collapse
|
48
|
Guggi D, Marschütz MK, Bernkop-Schnürch A. Matrix tablets based on thiolated poly(acrylic acid): pH-dependent variation in disintegration and mucoadhesion. Int J Pharm 2004; 274:97-105. [PMID: 15072786 DOI: 10.1016/j.ijpharm.2003.06.001] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2003] [Revised: 01/05/2004] [Accepted: 01/06/2004] [Indexed: 11/26/2022]
Abstract
This study examined the influence of the pH on the mucoadhesive and cohesive properties of polyarcylic acid (PAA) and thiolated PAA. The pH of PAA (molecular mass: 450 kDa) and of a corresponding PAA-cysteine conjugate was adjusted to 3, 4, 5, 6, 7 and 8. The amount of immobilised thiol groups and disulfide bonds was determined via Ellman's reagent. Tablets were compressed out of each pH-batch of both thiolated and unmodified PAA and the swelling behaviour, the disintegration time and the mucoadhesiveness were evaluated. The amount of thiol/disulfide groups per gram thiolated PAA of pH 3 and pH 8 was determined to be 332 +/- 94 micromol and 162 +/- 46 micromol, respectively. The thiolated PAA tablets displayed a minimum four-fold higher water uptake compared to unmodified PAA tablets. A faster and higher water uptake of both polymer types was observed above pH 5. Thiolated polymer tablets showed a 3-20-fold more prolonged disintegration time than unmodified PAA tablets. The cohesiveness of PAA-cysteine conjugate increased at higher pH, whereas the unmodified PAA behaved inversely. A 3-7-fold stronger mucoadhesiveness was observed for the PAA-cysteine conjugate tablets compared to unmodified PAA tablets. For both thiolated and unmodified polymer the mucoadhesiveness was 2-4-fold enhanced below pH 5. The difference in mucoadhesion between the two polymer types was most pronounced at these lower pH values. In this study substantial information regarding the pH-dependence of mucoadhesion and cohesion of unmodified polyacrylates and of thiolated polyacrylates is provided, representing helpful basic information for an ameliorated deployment of these polymers.
Collapse
Affiliation(s)
- Davide Guggi
- Institute of Pharmaceutical Technology and Biopharmaceutics, Center of Pharmacy, University of Vienna, Althanstr. 14, A-1090 Vienna, Austria
| | | | | |
Collapse
|
49
|
Perioli L, Ambrogi V, Rubini D, Giovagnoli S, Ricci M, Blasi P, Rossi C. Novel mucoadhesive buccal formulation containing metronidazole for the treatment of periodontal disease. J Control Release 2004; 95:521-33. [PMID: 15023463 DOI: 10.1016/j.jconrel.2003.12.018] [Citation(s) in RCA: 103] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2003] [Accepted: 12/23/2003] [Indexed: 10/26/2022]
Abstract
Mucoadhesive tablets using different mixture of cellulose and polyacrylic derivatives were prepared in order to obtain new formulations containing metronidazole for periodontal disease treatment. All tablets were characterized by swelling studies, ex vivo and in vivo mucoadhesive time, ex vivo mucoadhesion force, in vitro and in vivo release. The best mucoadhesive performance and the best in vitro drug release profile were achieved by using hydroxyethyl cellulose (HEC) and carbomer 940 2:2 ratio. The chosen tablet, containing 20 mg of metronidazole, performed 12 h drug sustained release with buccal concentrations always higher than its MIC.
Collapse
Affiliation(s)
- Luana Perioli
- Dipartimento di Chimica e Tecnologia del Farmaco, Università degli Studi di Perugia, Via del Liceo, 1, Perugia 06123, Italy.
| | | | | | | | | | | | | |
Collapse
|
50
|
Krauland AH, Bernkop-Schnürch A. Thiomers: development and in vitro evaluation of a peroral microparticulate peptide delivery system. Eur J Pharm Biopharm 2004; 57:181-7. [PMID: 15018973 DOI: 10.1016/j.ejpb.2003.09.011] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2003] [Revised: 09/26/2003] [Accepted: 09/26/2003] [Indexed: 11/21/2022]
Abstract
The aim of this study was to develop a peroral mucoadhesive microparticulate delivery system for peptide drugs. Microparticles containing either the mucoadhesive polymer poly(acrylic acid)-cysteine (PAA-Cys) or unmodified PAA, 15% insulin used as model peptide drug and 0, 30, 50 and 70% Eudragit RS (MP-RS0, MP-RS30, MP-RS50 and MP-RS70) were prepared by the emulsification solvent evaporation technique. Particle size distribution, release of incorporated insulin, mucoadhesive and swelling properties were examined. During preparation inter- and intramolecular cross-linking occurred, which could be quantified by the amount of disulfide bonds within the resulting particles; this was determined to be 69.2% of the total amount of thiol groups. This cross-linking led to a higher stability of the particles. Microparticles were spherical displaying a rough surface. The particle diameter was in the range of 1-110 microm in the following rank order beginning with the largest: MP-RS30>MP-RS50>MP-RS70=MP-RS0. The higher the ratio of Eudragit RS in the microparticles, the more prolonged was the release of insulin. In the case of MP-RS70, a sustained release over a time period of at least 60 min was achieved. Mucoadhesive properties and the capacity of water uptake followed the rank order: MP-RS0>MP-RS30>MP-RS50>MP-RS70. Compared to particles comprising unmodified PAA, the mucoadhesive properties of the thiolated microparticulate systems were up to 14-fold improved. According to these results PAA-Cys-Eudragit RS microparticles might be a promising tool for the peroral administration of peptide drugs.
Collapse
Affiliation(s)
- Alexander H Krauland
- Institute of Pharmaceutical Technology and Biopharmaceutics, Center of Pharmacy, University of Vienna, Vienna, Austria
| | | |
Collapse
|