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Majd H, Harker A, Edirisinghe M, Parhizkar M. Optimised release of tetracycline hydrochloride from core-sheath fibres produced by pressurised gyration. J Drug Deliv Sci Technol 2022. [DOI: 10.1016/j.jddst.2022.103359] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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2
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Glass Transition Temperature of PLGA Particles and the Influence on Drug Delivery Applications. Polymers (Basel) 2022; 14:polym14050993. [PMID: 35267816 PMCID: PMC8912735 DOI: 10.3390/polym14050993] [Citation(s) in RCA: 26] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Revised: 02/25/2022] [Accepted: 02/27/2022] [Indexed: 12/31/2022] Open
Abstract
Over recent decades, poly(lactic-co-glycolic acid) (PLGA) based nano- and micro- drug delivery vehicles have been rapidly developed since PLGA was approved by the Food and Drug Administration (FDA). Common factors that influence PLGA particle properties have been extensively studied by researchers, such as particle size, polydispersity index (PDI), surface morphology, zeta potential, and drug loading efficiency. These properties have all been found to be key factors for determining the drug release kinetics of the drug delivery particles. For drug delivery applications the drug release behavior is a critical property, and PLGA drug delivery systems are still plagued with the issue of burst release when a large portion of the drug is suddenly released from the particle rather than the controlled release the particles are designed for. Other properties of the particles can play a role in the drug release behavior, such as the glass transition temperature (Tg). The Tg, however, is an underreported property of current PLGA based drug delivery systems. This review summarizes the basic knowledge of the glass transition temperature in PLGA particles, the factors that influence the Tg, the effect of Tg on drug release behavior, and presents the recent awareness of the influence of Tg on drug delivery applications.
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Evaluation of physicochemical, structural, and antioxidant properties of microencapsulated seed extract from Securigera securidaca by co-crystallization method during storage time. BIOCATALYSIS AND AGRICULTURAL BIOTECHNOLOGY 2021. [DOI: 10.1016/j.bcab.2021.102090] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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4
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Yu S, Yuan H, Chai G, Peng K, Zou P, Li X, Li J, Zhou F, Chan HK, Zhou QT. Optimization of inhalable liposomal powder formulations and evaluation of their in vitro drug delivery behavior in Calu-3 human lung epithelial cells. Int J Pharm 2020; 586:119570. [PMID: 32593649 PMCID: PMC7423715 DOI: 10.1016/j.ijpharm.2020.119570] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2020] [Revised: 06/15/2020] [Accepted: 06/20/2020] [Indexed: 12/13/2022]
Abstract
Inhalation therapy has advantages for the treatment of multidrug resistant bacterial lung infections with high drug concentrations at the infection sites in the airways and reduced systemic exposure. We have developed liposomal formulations for pulmonary delivery of synergistic ciprofloxacin (Cipro) and colistin (Col) as the potential candidate for treatment of lung infections caused by multidrug resistant Gram-negative bacteria. This study aims to: (1) further optimize the powder formulation by adding drying stabilizers (polyvinyl pyrrolidone or poloxamer) to protect the liposomes during spray-freeze-drying; (2) evaluate the transport and cellular uptake of drugs in a human lung epithelial Calu-3 cell model. The liposomal powder formulations were produced using the ultrasonic spray-freeze-drying technique. The optimal formulation (F5) used mannitol (8% w/v) and sucrose (2% w/v) as the internal lyoprotectants. Adding external lyoprotectants/aerosolization enhancers (i.e. 8% w/v mannitol, 2% w/v sucrose and 1%, w/w PVP 10) produced the superior rehydrated EE values of ciprofloxacin and colistin (50.2 ± 0.9% for Cipro and 37.8 ± 1.2% for Col) as well as satisfactory aerosol performance (FPF: 34.2 ± 0.8% for Cipro and 33.6 ± 0.9% for Col). The cytotoxicity study indicated that F5 with the colistin concentration at 50 μg/mL and ciprofloxacin at 200 μg/mL was not cytotoxic to human lung epithelial Calu-3 cells. The intracellular uptake of ciprofloxacin was concentration-dependent in Calu-3 cells and the uptake of A-B was more than that of B-A for all samples (p < 0.05). This study demonstrates that co-delivery of ciprofloxacin and colistin in a single liposome can lower the transport capability of both drugs across the Calu-3 cell monolayer and their accumulation in the cells. These findings indicate that co-loaded liposomal powder of ciprofloxacin and colistin is a promising potential treatment for respiratory infections caused by multidrug resistant Gram-negative bacteria.
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Affiliation(s)
- Shihui Yu
- Department of Industrial and Physical Pharmacy, College of Pharmacy, Purdue University, 575 Stadium Mall Drive, West Lafayette, IN 47907, USA
| | - Huiya Yuan
- Department of Industrial and Physical Pharmacy, College of Pharmacy, Purdue University, 575 Stadium Mall Drive, West Lafayette, IN 47907, USA; School of Forensic Medicine, China Medical University, Shenyang 110122, China
| | - Guihong Chai
- Department of Industrial and Physical Pharmacy, College of Pharmacy, Purdue University, 575 Stadium Mall Drive, West Lafayette, IN 47907, USA
| | - Kuan Peng
- Department of Industrial and Physical Pharmacy, College of Pharmacy, Purdue University, 575 Stadium Mall Drive, West Lafayette, IN 47907, USA; School of Pharmacy, Shenyang Pharmaceutical University, Shenyang 110016, China
| | - Peizhi Zou
- Department of Industrial and Physical Pharmacy, College of Pharmacy, Purdue University, 575 Stadium Mall Drive, West Lafayette, IN 47907, USA
| | - Xuxi Li
- Department of Industrial and Physical Pharmacy, College of Pharmacy, Purdue University, 575 Stadium Mall Drive, West Lafayette, IN 47907, USA
| | - Jian Li
- Monash Biomedicine Discovery Institute and Department of Microbiology, Monash University, Clayton, Victoria 3800, Australia
| | - Fanfan Zhou
- Sydney Pharmacy School, The University of Sydney, Camperdown, NSW 2006, Australia
| | - Hak-Kim Chan
- Sydney Pharmacy School, The University of Sydney, Camperdown, NSW 2006, Australia
| | - Qi Tony Zhou
- Department of Industrial and Physical Pharmacy, College of Pharmacy, Purdue University, 575 Stadium Mall Drive, West Lafayette, IN 47907, USA.
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Price DN, Kunda NK, Ellis R, Muttil P. Design and Optimization of a Temperature-Stable Dry Powder BCG Vaccine. Pharm Res 2019; 37:11. [PMID: 31873825 DOI: 10.1007/s11095-019-2739-8] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2019] [Accepted: 11/24/2019] [Indexed: 12/22/2022]
Abstract
PURPOSE Loss of vaccine potency due to extreme temperature exposure during storage and transport remains a significant obstacle to the success of many vaccines, including the Bacille Calmette-Guérin (BCG) vaccine, the only vaccine available against Mycobacterium tuberculosis. BCG is a live, attenuated vaccine requiring refrigerated storage for viability. In this study, we formulated a temperature-stable BCG dry powder using the spray drying technique. METHODS We employed a factorial design to optimize our formulation of stabilizing excipients that included L-leucine, bovine serum albumin, polyvinylpyrrolidone, mannitol, and trehalose. Powders were characterized for their particle size, yield, water retention and uptake, glass transition temperature, and aerosol performance. Three optimal powder carrier mixtures were selected from the factorial design for BCG incorporation based on their stability-promoting and powder flow characteristics. Vaccine powders were also assessed for BCG viability and in vivo immunogenicity after long-term storage. RESULTS Live BCG was successfully spray-dried using the optimized carriers. Dry powder BCG showed no loss in viability (25°C, up to 60% relative humidity; RH) and ~2-log loss in viability (40°C, 75% RH) after one year of storage. The aerodynamic size of the powders was in the respirable range. Further, when healthy mice were immunized intradermally with reconstituted BCG powders (storage for 2 years), the vaccine retained its immunogenicity. CONCLUSION We developed a spray-dried BCG vaccine that was viable and antigenic after long-term storage. To our knowledge, this is a first study to show room temperature stability of live BCG vaccine without any loss in viability for 12 months.
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Affiliation(s)
- Dominique N Price
- Department of Pharmaceutical Sciences, College of Pharmacy, University of New Mexico, Health Sciences Center, Albuquerque, New Mexico, 87131, USA.,Biomedical Sciences Graduate Program, University of New Mexico, Health Sciences Center, Albuquerque, New Mexico, 87131, USA
| | - Nitesh K Kunda
- Department of Pharmaceutical Sciences, College of Pharmacy, University of New Mexico, Health Sciences Center, Albuquerque, New Mexico, 87131, USA.,Department of Pharmaceutical Sciences, College of Pharmacy and Health Sciences, St. John's University, Jamaica, New York, 11439, USA
| | - Rajaun Ellis
- Health Sciences Center, University of New Mexico, Albuquerque, New Mexico, 87131, USA.,Nova Southeastern University, Fort Lauderdale, Florida, 33314, USA
| | - Pavan Muttil
- Department of Pharmaceutical Sciences, College of Pharmacy, University of New Mexico, Health Sciences Center, Albuquerque, New Mexico, 87131, USA.
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Ghimire PP, Dassanayake AC, Wickramaratne NP, Jaroniec M. Polyvinyl pyrrolidone-assisted synthesis of size-tunable polymer spheres at elevated temperature and their conversion to nitrogen-containing carbon spheres. J Colloid Interface Sci 2019; 549:162-170. [DOI: 10.1016/j.jcis.2019.04.059] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2019] [Revised: 04/15/2019] [Accepted: 04/17/2019] [Indexed: 10/27/2022]
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7
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Madan M, Sikriwal D, Sharma G, Shukla N, Mandyal AK, Kale S, Gill D. Rational design of heat stable lyophilized rotavirus vaccine formulations. Hum Vaccin Immunother 2018; 14:2132-2141. [PMID: 29953317 PMCID: PMC6183320 DOI: 10.1080/21645515.2018.1487499] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2018] [Revised: 05/21/2018] [Accepted: 06/07/2018] [Indexed: 12/20/2022] Open
Abstract
To develop a safe and efficacious heat-stable rotavirus vaccine, new lyophilized formulations were developed using rotavirus serotypes constituting RotaTeq®. A series of formulation compositions, differing in buffering agents, bulking agents, cryoprotectants, amino acids and divalent cations, were screened for their ability to provide stability to rotavirus serotypes during lyophilization and when stored under elevated temperatures for extended periods. Lead formulations and lyophilization cycles were further optimized. Stability profiles of thus optimized formulations showed their ability to retain the potency of rotavirus for > 36 months at 5°C, 20 months at 37°C, and 7 months at 45°C. The heat-stable lyophilized rotavirus formulations developed met the all critical quality attributes for appearance, heat-stability during storage, moisture content as well as pH, viability and stability after reconstitution and has great potential to be used as vaccine candidates for improving access in low-income countries.
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Affiliation(s)
- Madhu Madan
- MSD Wellcome Trust Hilleman Labs Pvt. Ltd, Jamia Hamdard, Hamdard Nagar, New Delhi, India
| | - Deepa Sikriwal
- MSD Wellcome Trust Hilleman Labs Pvt. Ltd, Jamia Hamdard, Hamdard Nagar, New Delhi, India
| | - Gaurav Sharma
- MSD Wellcome Trust Hilleman Labs Pvt. Ltd, Jamia Hamdard, Hamdard Nagar, New Delhi, India
| | - Nidhi Shukla
- MSD Wellcome Trust Hilleman Labs Pvt. Ltd, Jamia Hamdard, Hamdard Nagar, New Delhi, India
| | - Ashwani Kumar Mandyal
- MSD Wellcome Trust Hilleman Labs Pvt. Ltd, Jamia Hamdard, Hamdard Nagar, New Delhi, India
| | - Sachin Kale
- MSD Wellcome Trust Hilleman Labs Pvt. Ltd, Jamia Hamdard, Hamdard Nagar, New Delhi, India
| | - Davinder Gill
- MSD Wellcome Trust Hilleman Labs Pvt. Ltd, Jamia Hamdard, Hamdard Nagar, New Delhi, India
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8
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Yang X, Hui Q, Yu B, Huang Z, Zhou P, Wang P, Wang Z, Pang S, Li J, Wang H, Lin L, Li X, Wang X. Design and Evaluation of Lyophilized Fibroblast Growth Factor 21 and Its Protection against Ischemia Cerebral Injury. Bioconjug Chem 2018; 29:287-295. [PMID: 29278321 DOI: 10.1021/acs.bioconjchem.7b00588] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
This study investigated the effect of the excipients, including glycine, mannitol, arginine, trehalose, sorbitol, and poloxamer188, on the stability of recombinant human fibroblast growth factor 21(FGF21) during the process of lyophilization and storage. The glass transition temperature (Tg), protein secondary structure, aggregation ratio, and the bioactivity of lyophilized FGF21 were measured. We furthermore investigated the effect of FGF21 against ischemia cerebral injury using the middle cerebral artery occlusion (MCAO) model in rats. The ischemia cerebral injury of MCAO rats was analyzed via 2,3,5-triphenyltetrazolium chloride and Nissl-staining. Endoplasmic reticulum (ER) stress related proteins were detected via Western blot. In this study, we found that aggregation was the primary mode of deterioration of lyophilized FGF21under accelerated storage conditions. Mannitol combined with trehalose and glycine formulations offers the most effective protein protection to reduce the aggregation. Administration of FGF21 protected cerebral ischemia and decreased ER stress related proteins in MCAO rats and PC12 cells.
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Affiliation(s)
- Xuanxin Yang
- School of Pharmacy, Wenzhou Medical University , Chashan University Park, Wenzhou 325035, China
| | - Qi Hui
- School of Pharmacy, Wenzhou Medical University , Chashan University Park, Wenzhou 325035, China
| | - Bingjie Yu
- School of Pharmacy, Wenzhou Medical University , Chashan University Park, Wenzhou 325035, China
| | - Zhen Huang
- School of Pharmacy, Wenzhou Medical University , Chashan University Park, Wenzhou 325035, China
| | - PeiPei Zhou
- School of Pharmacy, Wenzhou Medical University , Chashan University Park, Wenzhou 325035, China
| | - Panfeng Wang
- School of Pharmacy, Wenzhou Medical University , Chashan University Park, Wenzhou 325035, China
| | - Zhitao Wang
- School of Pharmacy, Wenzhou Medical University , Chashan University Park, Wenzhou 325035, China
| | - Shucai Pang
- School of Pharmacy, Wenzhou Medical University , Chashan University Park, Wenzhou 325035, China
| | - Jinghang Li
- Swanson School of Engineering, University of Pittsburgh , Pittsburgh, Pennsylvania 15261, United States
| | - Hanshi Wang
- School of Pharmacy, Wenzhou Medical University , Chashan University Park, Wenzhou 325035, China
| | - Li Lin
- School of Pharmacy, Wenzhou Medical University , Chashan University Park, Wenzhou 325035, China
| | - Xiaokun Li
- School of Pharmacy, Wenzhou Medical University , Chashan University Park, Wenzhou 325035, China
| | - Xiaojie Wang
- School of Pharmacy, Wenzhou Medical University , Chashan University Park, Wenzhou 325035, China
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9
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Jawad R, Elleman C, Martin GP, Royall PG. Crystallisation of freeze-dried sucrose in model mixtures that represent the amorphous sugar matrices present in confectionery. Food Funct 2018; 9:4621-4634. [DOI: 10.1039/c8fo00729b] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Sucrose crystallization is highly dependent on the presence of other common food ingredients within an amorphous freeze-dried matrix.
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Affiliation(s)
- Rim Jawad
- Institute of Pharmaceutical Science
- King's College London
- London SE1 9NH
- UK
| | - Carole Elleman
- The Reading Science Centre
- Reading Scientific Services Ltd
- Reading RG6 6LA
- UK
| | - Gary P. Martin
- Institute of Pharmaceutical Science
- King's College London
- London SE1 9NH
- UK
| | - Paul G. Royall
- Institute of Pharmaceutical Science
- King's College London
- London SE1 9NH
- UK
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10
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Teng D, Kawai K, Mikajiri S, Hagura Y. Stabilization of freeze-dried Lactobacillus paracasei subsp. paracasei JCM 8130 T with the addition of disaccharides, polymers, and their mixtures. Biosci Biotechnol Biochem 2017; 81:768-773. [PMID: 28103748 DOI: 10.1080/09168451.2017.1279852] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Although freeze-drying is a widely used dehydration technique for the stabilizing of unstable lactic acid bacteria, Lactobacillus paracasei subsp. paracasei JCM 8130T (L. paracasei) is destabilized after freeze-drying and subsequent storage. In order to improve the stability of freeze-dried L. paracasei, effects of disaccharides (sucrose and trehalose), polymers (maltodextrin; MD and bovine serum albumin; BSA), and their mixtures on the survival rate of freeze-dried L. paracasei were investigated. The survival rate of non-additive sample decreased slightly after freeze-drying but decreased drastically after subsequent storage at 37 °C for 4 weeks. The reduction was diminished by the addition of disaccharides and polymers. The stabilizing effect of disaccharides was not affected by the co-addition of MD. In contrast, the disaccharide-BSA mixtures had a synergistic stabilizing effect, and the survival rates were largely maintained even after storage. It is suggested that the synergistic effect originates from the conformational stabilization of the dehydrated bacteria.
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Affiliation(s)
- Da Teng
- a Department of Biofunctional Science and Technology, Graduate School of Biosphere Science , Hiroshima University , Hiroshima , Japan
| | - Kiyoshi Kawai
- a Department of Biofunctional Science and Technology, Graduate School of Biosphere Science , Hiroshima University , Hiroshima , Japan
| | - Shuto Mikajiri
- a Department of Biofunctional Science and Technology, Graduate School of Biosphere Science , Hiroshima University , Hiroshima , Japan
| | - Yoshio Hagura
- a Department of Biofunctional Science and Technology, Graduate School of Biosphere Science , Hiroshima University , Hiroshima , Japan
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11
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Deignan G, Goldthorpe IA. The dependence of silver nanowire stability on network composition and processing parameters. RSC Adv 2017. [DOI: 10.1039/c7ra06524h] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Variables such as nanowire diameter and density are found to have a significant effect on the degradation of silver nanowires.
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Affiliation(s)
- Geoffrey Deignan
- Department of Electrical and Computer Engineering
- University of Waterloo
- Waterloo
- Canada
- Waterloo Institute for Nanotechnology
| | - Irene A. Goldthorpe
- Department of Electrical and Computer Engineering
- University of Waterloo
- Waterloo
- Canada
- Waterloo Institute for Nanotechnology
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12
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Koo CKW, Senecal K, Senecal A, Nugen SR. Dehydration of bacteriophages in electrospun nanofibers: effect of excipients in polymeric solutions. NANOTECHNOLOGY 2016; 27:485102. [PMID: 27819799 DOI: 10.1088/0957-4484/27/48/485102] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Bacteriophages are viruses capable of infecting and lysing target bacterial cells; as such they have potential applications in agriculture for decontamination of foods, food contact surfaces and food rinse water. Although bacteriophages can retain infectivity long-term using lyophilized storage, the process of freeze-drying can be time consuming and expensive. In this study, electrospinning was used for dehydrating bacteriophages in polyvinylpyrrolidone polymer solutions with addition of excipients (sodium chloride, magnesium sulfate, Tris-HCl, sucrose) in deionized water. The high voltage dehydration reduced the infectivity of bacteriophages following electrospinning, with the damaging effect abated with addition of storage media (SM) buffer and sucrose. SM buffer and sucrose also provided the most protection over extended storage (8 weeks; 20 °C; 1% relative humidity) by mitigating environmental effects on the dried bacteriophages. Magnesium sulfate however provided the least protection due to coagulation effects of the ion, which can disrupt the native conformation of the bacteriophage protein coat. Storage temperatures (20 °C, 4 °C and -20 °C; 1% relative humidity) had a minimal effect while relative humidity had substantial effect on the infectivity of bacteriophages. Nanofibers stored in higher relative humidity (33% and 75%) underwent considerable damage due to extensive water absorption and disruption of the fibers. Overall, following storage of nanofiber mats for eight weeks at ambient temperatures, high infective phage concentrations (106-107 PFU ml-1) were retained. Therefore, this study provided valuable insights on preservation and dehydration of bacteriophages by electrospinning in comparison to freeze drying and liquid storage, and the influence of excipients on the viability of bacteriophages.
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Affiliation(s)
- Charmaine K W Koo
- Department of Food Science, University of Massachusetts, Amherst, MA 01003, USA
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13
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Balanč B, Trifković K, Đorđević V, Marković S, Pjanović R, Nedović V, Bugarski B. Novel resveratrol delivery systems based on alginate-sucrose and alginate-chitosan microbeads containing liposomes. Food Hydrocoll 2016. [DOI: 10.1016/j.foodhyd.2016.07.005] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
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14
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Synthesis, characterization and material properties of novel poly vinyl acetate grafted pectin. ACTA ACUST UNITED AC 2016. [DOI: 10.1007/s12588-015-9117-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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15
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Koczkur KM, Mourdikoudis S, Polavarapu L, Skrabalak SE. Polyvinylpyrrolidone (PVP) in nanoparticle synthesis. Dalton Trans 2015; 44:17883-905. [DOI: 10.1039/c5dt02964c] [Citation(s) in RCA: 911] [Impact Index Per Article: 101.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
The versatile role of PVP in nanoparticle synthesis is discussed in this Perspective article.
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Affiliation(s)
| | | | - Lakshminarayana Polavarapu
- Photonics and Optoelectronics Group
- Department of Physics and CeNS
- Ludwig-Maximilians-Universität München
- Munich
- Germany
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16
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Sardar BR, Singhal RS. Characterization of co-crystallized sucrose entrapped with cardamom oleoresin. J FOOD ENG 2013. [DOI: 10.1016/j.jfoodeng.2012.12.011] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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17
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Observing the temperature dependent transition of the GP2 peptide using terahertz spectroscopy. PLoS One 2012; 7:e50306. [PMID: 23209703 PMCID: PMC3508986 DOI: 10.1371/journal.pone.0050306] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2012] [Accepted: 10/18/2012] [Indexed: 11/19/2022] Open
Abstract
The GP2 peptide is derived from the Human Epidermal growth factor Receptor 2 (HER2/nue), a marker protein for breast cancer present in saliva. In this paper we study the temperature dependent behavior of hydrated GP2 at terahertz frequencies and find that the peptide undergoes a dynamic transition between 200 and 220 K. By fitting suitable molecular models to the frequency response we determine the molecular processes involved above and below the transition temperature (T(D)). In particular, we show that below T(D) the dynamic transition is dominated by a simple harmonic vibration with a slow and temperature dependent relaxation time constant and that above T(D), the dynamic behavior is governed by two oscillators, one of which has a fast and temperature independent relaxation time constant and the other of which is a heavily damped oscillator with a slow and temperature dependent time constant. Furthermore a red shifting of the characteristic frequency of the damped oscillator was observed, confirming the presence of a non-harmonic vibration potential. Our measurements and modeling of GP2 highlight the unique capabilities of THz spectroscopy for protein characterization.
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18
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Xia X, Zeng J, Oetjen LK, Li Q, Xia Y. Quantitative analysis of the role played by poly(vinylpyrrolidone) in seed-mediated growth of Ag nanocrystals. J Am Chem Soc 2012; 134:1793-801. [PMID: 22206387 DOI: 10.1021/ja210047e] [Citation(s) in RCA: 232] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
This article presents a quantitative analysis of the role played by poly(vinylpyrrolidone) (PVP) in seed-mediated growth of Ag nanocrystals. Starting from Ag nanocubes encased by {100} facets as the seeds, the resultant nanocrystals could take different shapes depending on the concentration of PVP in the solution. If the concentration was above a critical value, the seeds simply grew into larger cubes still enclosed by {100} facets. When the concentration fell below a critical value, the seeds would evolve into cuboctahedrons enclosed by a mix of {100} and {111} facets and eventually octahedrons completely covered by {111} facets. We derived the coverage density of PVP on Ag(100) surface by combining the results from two measurements: (i) cubic seeds were followed to grow at a fixed initial concentration of PVP to find out when {111} facets started to appear on the surface, and (ii) cubic seeds were allowed to grow at reduced initial concentrations of PVP to see at which concentration {111} facets started to appear from the very beginning. We could calculate the coverage density of PVP from the differences in PVP concentration and the total surface area of Ag nanocubes between these two samples. The coverage density was found to be 140 and 30 repeating units per nm(2) for PVP of 55,000 and 10,000 g/mol in molecular weight, respectively, for cubic seeds of 40 nm in edge length. These values dropped slightly to 100 and 20 repeating units per nm(2), respectively, when 100 nm Ag cubes were used as the seeds.
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Affiliation(s)
- Xiaohu Xia
- Department of Biomedical Engineering, Washington University, St. Louis, Missouri 63130, USA
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19
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Oliveira CP, Ribeiro MEN, Ricardo NM, Souza TVDP, Moura CL, Chaibundit C, Yeates SG, Nixon K, Attwood D. The effect of water-soluble polymers, PEG and PVP, on the solubilisation of griseofulvin in aqueous micellar solutions of Pluronic F127. Int J Pharm 2011; 421:252-7. [DOI: 10.1016/j.ijpharm.2011.10.010] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2011] [Revised: 09/26/2011] [Accepted: 10/01/2011] [Indexed: 10/16/2022]
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20
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Bhattacharya S, Suryanarayanan R. Molecular Motions in Sucrose-PVP and Sucrose-Sorbitol Dispersions: I. Implications of Global and Local Mobility on Stability. Pharm Res 2011; 28:2191-203. [DOI: 10.1007/s11095-011-0447-0] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2010] [Accepted: 04/05/2011] [Indexed: 11/29/2022]
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21
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Zhang SZ, Qian H, Wang Z, Fan JL, Zhou Q, Chen GM, Li R, Fu S, Sun J. Preliminary study on the freeze-drying of human bone marrow-derived mesenchymal stem cells. J Zhejiang Univ Sci B 2011; 11:889-94. [PMID: 21043058 DOI: 10.1631/jzus.b1000184] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Long-term preservation and easy transportation of human bone marrow-derived mesenchymal stem cells (hBM-MSCs) will facilitate their application in medical treatment and bioengineering. A pilot study on the freeze-drying of hBM-MSCs was carried out. hBM-MSCs were loaded with trehalose. The glass transition temperature of the freeze-drying suspension was measured to provide information for the cooling and primary drying experiment. After freeze-drying, various rehydration processes were tested. The highest recovery rate of hBM-MSCs was (69.33±13.08)%. Possible methods to improve freeze-drying outcomes are discussed. In conclusion, the present study has laid a foundation for the freeze-drying hBM-MSCs.
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Affiliation(s)
- Shao-zhi Zhang
- Refrigeration and Cryogenic Engineering Institute, Zhejiang University, Hangzhou, China
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22
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Xu MJ, Chen GM, Fan JL, Liu JH, Xu XG, Zhang SZ. Moisture sorption characteristics of freeze-dried human platelets. J Zhejiang Univ Sci B 2011; 12:210-8. [PMID: 21370506 DOI: 10.1631/jzus.b1010199] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Freeze-drying is a promising method for a long-term storage of human platelets. The moisture sorption characteristics of freeze-dried human platelets (FDHPs) were studied in this paper. The moisture sorption isotherms of FDHPs and freeze-dried lyophilization buffer (FDLB) were measured at 4, 25, and 37 °C. The experimental data were fitted to Brunauer-Emmett-Teller (BET) and Guggenheim-Anderson-de Boer (GAB) equations. There were no significant statistical differences (P>0.05) between the sorption characteristics of FDHPs and FDLB at 4 and 25 °C, while FDHPs absorbed more water at 37 °C. The net isosteric heat of sorption was derived. The heat for FDHPs showed an abnormal negative value at low moisture contents when 25 and 37 °C data were used. Dynamic sorption experiments were carried out at 25 °C with environmental water activity controlled at 0.75, 0.85, and 0.90. The moisture diffusion coefficient was fitted to be 8.24×10(-12) m(2)/s when experimental data at initial time were used. These results would be helpful in choosing prehydration and storage condition for FDHPs.
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Affiliation(s)
- Meng-jie Xu
- Institute of Refrigeration and Cryogenics, Zhejiang University, Hangzhou 310027, China
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23
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Chen C, Han D, Cai C, Tang X. An overview of liposome lyophilization and its future potential. J Control Release 2010; 142:299-311. [DOI: 10.1016/j.jconrel.2009.10.024] [Citation(s) in RCA: 270] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2009] [Accepted: 10/20/2009] [Indexed: 01/19/2023]
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24
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25
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Dranca I, Lupascu T. Implications of Global and Local Mobility in Amorphous Excipients as Determined by DSC and TM DSC. CHEMISTRY JOURNAL OF MOLDOVA 2009. [DOI: 10.19261/cjm.2009.04(2).02] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
The paper explores the use of differential scanning calorimetry (DSC) and temperature modulated differential scanning calorimetry (TM DSC) to study α- and β- processes in amorphous sucrose and trehalose. The real part of the complex heat capacity is evaluated at the frequencies, f, from 5 to 20mHz. β-relaxations were studied by annealing glassy samples at different temperatures and subsequently heating at different rates in a differential scanning calorimeter.
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26
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Xing Z, Yang G. Crystallization, melting behavior, and wettability of poly(ε-caprolactone) and poly(ε-caprolactone)/ poly(N-vinylpyrrolidone) blends. J Appl Polym Sci 2009. [DOI: 10.1002/app.30069] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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27
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Implications of Global and Local Mobility in Amorphous Sucrose and Trehalose as Determined by Differential Scanning Calorimetry. Pharm Res 2009; 26:1064-72. [DOI: 10.1007/s11095-008-9817-7] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2008] [Accepted: 12/16/2008] [Indexed: 11/27/2022]
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28
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Aso Y, Yoshioka S, Miyazaki T, Kawanishi T. Feasibility of 19F-NMR for Assessing the Molecular Mobility of Flufenamic Acid in Solid Dispersions. Chem Pharm Bull (Tokyo) 2009; 57:61-4. [DOI: 10.1248/cpb.57.61] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Affiliation(s)
- Yukio Aso
- National Institute of Health Sciences
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29
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Gieseler H, Kramer T, Pikal MJ. Use of manometric temperature measurement (MTM) and SMART™ freeze dryer technology for development of an optimized freeze‐drying cycle. J Pharm Sci 2007; 96:3402-18. [PMID: 17853427 DOI: 10.1002/jps.20982] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
This report provides, for the first time, a summary of experiments using SMART Freeze Dryer technology during a 9 month testing period. A minimum ice sublimation area of about 300 cm(2) for the laboratory freeze dryer, with a chamber volume 107.5 L, was found consistent with data obtained during previous experiments with a smaller freeze dryer (52 L). Good reproducibility was found for cycle design with different type of excipients, formulations, and vials used. SMART primary drying end point estimates were accurate in the majority of the experiments, but showed an over prediction of primary cycle time when the product did not fully achieve steady state conditions before the first MTM measurement was performed. Product resistance data for 5% sucrose mixtures at varying fill depths were very reproducible. Product temperature determined by SMART was typically in good agreement with thermocouple data through about 50% of primary drying time, with significant deviations occurring near the end of primary drying, as expected, but showing a bias much earlier in primary drying for high solid content formulations (16.6% Pfizer product) and polyvinylpyrrolidone (40 kDa) likely due to water "re-adsorption" by the amorphous product during the MTM test.
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Affiliation(s)
- Henning Gieseler
- School of Pharmacy, University of Connecticut, 69 North Eagleville Road, Storrs, CT 06269, USA.
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30
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Corbanie E, Remon J, Van Reeth K, Landman W, van Eck J, Vervaet C. Spray drying of an attenuated live Newcastle disease vaccine virus intended for respiratory mass vaccination of poultry. Vaccine 2007; 25:8306-17. [DOI: 10.1016/j.vaccine.2007.09.049] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2007] [Revised: 09/13/2007] [Accepted: 09/20/2007] [Indexed: 11/29/2022]
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31
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Tantry JS, Tank J, Suryanarayanan R. Processing-Induced Phase Transitions of Theophylline—Implications on the Dissolution of Theophylline Tablets. J Pharm Sci 2007; 96:1434-44. [PMID: 17455350 DOI: 10.1002/jps.20746] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Aqueous wet massing of stable anhydrous theophylline (A) with polyvinylpyrrolidone (PVP) resulted in its complete transformation to theophylline monohydrate (M). Drying at 45 degrees C, resulted in the formation of metastable anhydrous theophylline (A*) which then transformed to A. PVP, a known crystallization inhibitor, was effective in inhibiting the A* --> A transition. The higher molecular weight polymer, PVP K90, was more effective in inhibiting the A* --> A transition as compared to PVP K17. The disappearance of M, and the formation of A* and A was simultaneously monitored by XRD. An increase in the drying temperature from 45 to 55 degrees C accelerated the A* --> A transition. In granules prepared by the high-shear process, approximately 50% of theophylline existed as A and the rest as A*. In contrast, the fluid-bed granulation process yielded granules containing only A. Thus, the physical form of theophylline in tablets was influenced by the molecular weight of the binding agent, the granulation method, and the drying temperature. Using A as the starting material, tablets were manufactured by high-shear aqueous wet granulation process and the A* content was quantified. These tablets were stored under various relative humidity (RH) conditions at 25 degrees C for 2 weeks. Storage at RH >or= 33% caused complete A* --> A conversion accompanied by a pronounced decrease in the initial dissolution rate indicating that phase transitions during processing and storage can have a significant influence on product performance.
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Affiliation(s)
- Jaidev S Tantry
- Department of Pharmaceutics, College of Pharmacy, University of Minnesota, 308 Harvard Street SE, Minneapolis, Minnesota 55455, USA
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32
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Mao C, Chamarthy SP, Pinal R. Time-dependence of molecular mobility during structural relaxation and its impact on organic amorphous solids: an investigation based on a calorimetric approach. Pharm Res 2007; 23:1906-17. [PMID: 16858653 DOI: 10.1007/s11095-006-9008-3] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2005] [Accepted: 03/13/2006] [Indexed: 11/25/2022]
Abstract
PURPOSE To develop a calorimetry-based model for estimating the time-dependence of molecular mobility during the isothermal relaxation of amorphous organic compounds below their glass transition temperature (Tg). METHODS The time-dependent enthalpy relaxation times of amorphous sorbitol, indomethacin, trehalose and sucrose were estimated based on the nonlinear Adam-Gibbs equation. Fragility was determined from the scanning rate dependence of Tg. Time evolution of the fictive temperature was determined from Tg, the heat capacity of the amorphous and crystalline forms, and from the enthalpy relaxation data. RESULTS Relaxation time changes significantly upon annealing for all compounds studied. The magnitude of the increase in relaxation time does not depend on any one parameter but on four parameters: Tg, fragility, and the crystal-liquid and glass-liquid heat capacity differences. The obtained mobility data for indomethacin and sucrose, both stored at Tg-16 K, correlated much better with their different crystallization tendencies than did the Kohlrausch-Williams-Watts (KWW) equation. CONCLUSIONS The observed changes in relaxation time help explain and address the limitations of the KWW approach. Due consideration of the time-dependence of molecular mobility upon storage is a key element for improving the understanding necessary for stabilizing amorphous formulations.
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Affiliation(s)
- Chen Mao
- Department of Industrial and Physical Pharmacy, Purdue University, 575 Stadium Mall Drive, West Lafayette, Indiana 47907, USA
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33
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Aso Y, Yoshioka S. Molecular mobility of nifedipine-PVP and phenobarbital-PVP solid dispersions as measured by 13C-NMR spin-lattice relaxation time. J Pharm Sci 2006; 95:318-25. [PMID: 16372315 DOI: 10.1002/jps.20545] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Amorphous nifedipine-PVP and phenobarbital-PVP solid dispersions with various drug contents were prepared by melting and subsequent rapid cooling of mixtures of PVP and nifedipine, or phenobarbital. Chemical shifts and spin-lattice relaxation times (T(1)) of PVP, nifedipine, and phenobarbital carbons were determined by (13)C-CP/MAS NMR to elucidate drug-PVP interactions and the localized molecular mobility of drug and PVP in the solid dispersions. The chemical shift of the PVP carbonyl carbon increased as the drug content increased, appearing to reach a plateau at a molar ratio of drug to PVP monomer unit of approximately 1:1, suggesting hydrogen bond interactions between the PVP carbonyl group and the drugs. T(1) of the PVP carbonyl carbon in the solid dispersions increased as the drug content increased, indicating that the mobility of the PVP carbonyl carbon was decreased by hydrogen bond interactions. T(1) of the drug carbons increased as the PVP content increased, and this increase in T(1) became less obvious when the molar ratio of PVP monomer unit to drug exceeded approximately 1:1. These results suggest that the localized motion of the PVP pyrrolidone ring and the drug molecules is reduced by hydrogen bond interactions. Decreases in localized mobility appear to be one of the factors that stabilize the amorphous state of drugs.
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Affiliation(s)
- Yukio Aso
- Division of Drugs, National Institute of Health Sciences, Setagaya, Tokyo, Japan.
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34
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Dumont F, Marechal PA, Gervais P. Involvement of two specific causes of cell mortality in freeze-thaw cycles with freezing to -196 degrees C. Appl Environ Microbiol 2006; 72:1330-5. [PMID: 16461684 PMCID: PMC1392953 DOI: 10.1128/aem.72.2.1330-1335.2006] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2005] [Accepted: 12/05/2005] [Indexed: 11/20/2022] Open
Abstract
The purpose of this study was to examine cell viability after freezing. Two distinct ranges of temperature were identified as corresponding to stages at which yeast cell mortality occurred during freezing to -196 degrees C. The upper temperature range was related to the temperature of crystallization of the medium, which was dependent on the solute concentration; in this range mortality was prevented by high solute concentrations, and the proportion of the medium in the vitreous state was greater than the proportion in the crystallized state. The lower temperature range was related to recrystallization that occurred during thawing. Mortality in this temperature range was increased by a high cooling rate and/or high solute concentration in the freezing medium and a low temperature (less than -70 degrees C). However, a high rate of thawing prevented yeast mortality in this lower temperature range. Overall, it was found that cell viability could be conserved better under freezing conditions by increasing the osmotic pressure of the medium and by using an increased warming rate.
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Affiliation(s)
- Frédéric Dumont
- Laboratoire de Génie des Procédés Alimentaires et Biotechnologiques, ENSBANA, 1 Esplanade Erasme, 21000 Dijon, France
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35
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Miyazaki T, Yoshioka S, Aso Y. Physical Stability of Amorphous Acetanilide Derivatives Improved by Polymer Excipients. Chem Pharm Bull (Tokyo) 2006; 54:1207-10. [PMID: 16880672 DOI: 10.1248/cpb.54.1207] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Crystallization rates of drug-polymer solid dispersions prepared with acetaminophen (ACA) and p-aminoacetanilide (AAA) as model drugs, and polyvinylpyrrolidone and polyacrylic acid (PAA) as model polymers were measured in order to further examine the significance of drug-polymer interactions. The crystallization of AAA and ACA was inhibited by mixing those polymers. The most effective inhibition was observed with solid dispersions of AAA and PAA. The combination of AAA and PAA showed a markedly longer enthalpy relaxation time relative to drug alone as well as a higher T(g) than predicted by the Gordon-Taylor equation, indicating the existence of a strong interaction between the two components. These observations suggest that crystallization is effectively inhibited by combinations of drug and polymer that show a strong intermolecular interaction due to proton transfer between acidic and basic functional groups.
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Affiliation(s)
- Tamaki Miyazaki
- Division of Drugs, National Institute of Health Sciences, 1-18-1 Kamiyoga, Setagaya-ku, Tokyo 158-8501, Japan.
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36
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Lappalainen M, Pitkänen I, Harjunen P. Quantification of low levels of amorphous content in sucrose by hyperDSC. Int J Pharm 2006; 307:150-5. [PMID: 16288841 DOI: 10.1016/j.ijpharm.2005.09.029] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2005] [Revised: 08/30/2005] [Accepted: 09/12/2005] [Indexed: 11/28/2022]
Abstract
A method was developed for the quantification of low levels of amorphous content in sucrose with hyperDSC. The method was based on the fact that the change of specific heat at the glass transition is linearly proportional to the amorphous content. It was found out that as annealing time increased, the glass transition temperature moved to a higher temperature and the change of specific heat increased. DeltaC(p) for annealed totally amorphous sucrose was 0.761+/-0.012 Jg(-1) degrees C(-1). Synthetic mixtures with various proportions of crystalline and amorphous sucrose were prepared. The following linear regression between DeltaC(p) and amorphous content was obtained: DeltaC(p)=0.0075x - 0.00484 (R=0.999). The limit of detection (LOD) and the limit of quantification (LOQ) values were 0.062 and 0.207%, respectively. The effect of grinding time on the amorphous content of crystalline sucrose was studied and a correlation between grinding time and amorphous content of sucrose was found. It was also found that the amorphous content could only attain a value of about 80-90% by grinding in the way used in this study.
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Affiliation(s)
- Minna Lappalainen
- University of Jyväskylä, Department of Chemistry, FIN-40014 University of Jyväskylä, Finland.
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37
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Lu D, Hickey AJ. Liposomal dry powders as aerosols for pulmonary delivery of proteins. AAPS PharmSciTech 2005; 6:E641-8. [PMID: 16408866 PMCID: PMC2750613 DOI: 10.1208/pt060480] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
The purpose of this research was to develop liposomal dry powder aerosols for protein delivery. The delivery of stable protein formulations is essential for protein subunit vaccine delivery, which requires local delivery to macrophages in the lungs. Beta-glucuronidase (GUS) was used as a model protein to evaluate dry powder liposomes as inhaled delivery vehicles. Dimyristoyl phosphatylcholine:cholesterol (7:3) was selected as the liposome composition. The lyophilization of liposomes, micronization of the powders, aerosolization using a dry powder inhaler (DPI), and in vitro aerodynamic fine particle fraction upon collection in a twin-stage liquid impinger were evaluated. After lyophilization and jet-milling, the total amount of GUS and its activity, representing encapsulation efficiency and stability, were evaluated. The GUS amount and activity were measured and compared with freshly-prepared liposomes in the presence of mannitol, 43% of initial GUS amount, 29% of GUS activity after lyophilization and 36% of GUS amount, 22% of activity after micronization were obtained. Emitted doses from dry powder inhaler were 53%, 58%, 66%, and 73% for liposome powder:mannitol carrier ratios of 1:0, 1:4, 1:9, and 1:19. Fifteen percent of the liposome particles were less than 6.4 mum in aerodynamic diameter. The results demonstrate that milled liposome powders containing protein molecules can be aerosolized effectively at a fixed flow rate. Influences of different cryoprotectants on lyophilization of protein liposome formulations are reported. The feasibility of using liposomal dry powder aerosols for protein delivery has been demonstrated but further optimization is required in the context of specific therapeutic proteins.
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Affiliation(s)
- Dongmei Lu
- School of Pharmacy, CB#7360, University of North Carolina at Chapel Hill, Kerr Hall 1311, 27599 Chapel Hill, NC
| | - Anthony J. Hickey
- School of Pharmacy, CB#7360, University of North Carolina at Chapel Hill, Kerr Hall 1311, 27599 Chapel Hill, NC
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Izutsu KI, Aoyagi N, Kojima S. Effect of Polymer Size and Cosolutes on Phase Separation of Poly(Vinylpyrrolidone) (PVP) and Dextran in Frozen Solutions. J Pharm Sci 2005; 94:709-17. [PMID: 15682383 DOI: 10.1002/jps.20292] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The aim of this study was to elucidate the effect of the molecular weight of polymers on their miscibility in frozen solutions to model the physical properties of freeze-dried pharmaceutical formulations. Thermal analysis of frozen solutions containing poly(vinylpyrrolidone) (PVP) and dextran of various molecular weights was performed at polymer concentrations below the binodal curve at room temperature. Frozen solutions containing PVP 29,000 and dextran 10,200 showed two thermal transitions (glass transition temperature of maximally freeze-concentrated solution: Tg') representing two freeze-concentrated amorphous phases, each containing predominantly one of the polymers. A combination of smaller polymers (PVP 10,000 and dextran 1,060) was freeze-concentrated into an amorphous mixture phase across a wide range of concentration ratios. Combinations of intermediate size polymers separated into two freeze-concentrated phases only at certain concentration ratios. Addition of NaCl prevented the phase separation of PVP and dextran in the aqueous and frozen solutions. Higher concentrations of NaCl were required to retain the miscibility of larger polymer combinations in the freeze-concentrate. The molecular weights of the component polymers, polymer concentration ratio, and cosolute composition are the important factors that determine component miscibility in frozen solutions.
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Affiliation(s)
- Ken-ichi Izutsu
- National Institute of Health Sciences, Kamiyoga, Setagaya 158-8501, Tokyo, Japan.
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Garcia-Contreras L, Smyth HDC. Liquid-Spray or Dry-Powder Systems for Inhaled Delivery of Peptide and Proteins? ACTA ACUST UNITED AC 2005. [DOI: 10.2165/00137696-200503010-00004] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
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40
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Aso Y, Yoshioka S, Kojima S. Molecular mobility‐based estimation of the crystallization rates of amorphous nifedipine and phenobarbital in poly(vinylpyrrolidone) solid dispersions. J Pharm Sci 2004; 93:384-91. [PMID: 14705195 DOI: 10.1002/jps.10526] [Citation(s) in RCA: 120] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
The overall crystallization rates and mean relaxation times of amorphous nifedipine and phenobarbital in the presence of poly(vinylpyrrolidone) (PVP) were determined at various temperatures to gain further insight into the effect of molecular mobility on the crystallization rates of amorphous drugs and the possibility of predicting stability from their molecular mobility. Nifedipine-PVP (9:1 w/w) and phenobarbital-PVP (95:5 w/w) solid dispersions were prepared by melting and rapidly cooling mixtures of each drug and PVP. The amount of amorphous nifedipine remaining in the solid dispersion was calculated from the heat of crystallization,which was obtained by differential scanning calorimetry. The amount of amorphous phenobarbital remaining in the solid dispersion was estimated from the change in the heat capacity at its glass transition temperature (T(g)). The time required for the amount of amorphous drug remaining to fall to 90% (t(90)) was calculated from the profile of time versus the amount of amorphous drug remaining. The t(90) values for the solid dispersions studied were 100-1000 times longer than those of pure amorphous drugs when compared at the same temperature. Enthalpy relaxation of the amorphous drugs in the solid dispersions was reduced compared with that in the pure amorphous drugs, indicating that the molecular mobility of the amorphous drugs is reduced in the presence of PVP. The temperature dependence of mean relaxation time (tau) for the nifedipine-PVP solid dispersion was calculated using the Adam-Gibbs-Vogel equation. Parameters D and T(0) in this equation were estimated from the heating rate dependence of T(g). Similar temperature dependence was observed for t(90) and tau values of the solid dispersion, indicating that the information on the temperature dependence of the molecular mobility, along with the crystallization data obtained at around the T(g), are useful for estimating the t(90) of overall crystallization at temperatures below T(g) in the presence of excipients.
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Affiliation(s)
- Yukio Aso
- National Institute of Health Sciences, 1-18-1 Kamiyoga, Setagaya-ku, Tokyo 158-8501, Japan.
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41
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Berggren J, Alderborn G. Long-term stabilisation potential of poly(vinylpyrrolidone) for amorphous lactose in spray-dried composites. Eur J Pharm Sci 2004; 21:209-15. [PMID: 14757492 DOI: 10.1016/j.ejps.2003.10.005] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The aim of this study was to investigate the potential of poly(vinylpyrrolidone) (PVP) to inhibit the crystallisation of amorphous lactose during storage of the composites up to 6 months. Short-term stability was assessed by microcalorimetry over 10 days and long-term stability by storage in desiccators with different relative humidities for 3 and 6 months. The solid-state structure of the particles after storage was analysed by differential scanning calorimetry. It was found that the presence of PVP increased the critical relative humidity (RH) for crystallisation relative to the pure lactose and both the proportion and the molecular weight of the PVP affected the stabilisation of the amorphous phase. The difference in critical RH between the materials increased over time. The T(g) of the materials was generally reduced due to the absorption of water and it is suggested that the inhibiting effect therefore is related mainly to a specific interaction between lactose and PVP, rather than to a counteracting effect of the polymer on the moisture induced depression of T(g).
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Affiliation(s)
- Jonas Berggren
- Department of Pharmacy, Uppsala University, Box 580, SE-751 23, Uppsala, Sweden.
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Berggren J, Alderborn G. Effect of polymer content and molecular weight on the morphology and heat- and moisture-induced transformations of spray-dried composite particles of amorphous lactose and poly(vinylpyrrolidone). Pharm Res 2003; 20:1039-46. [PMID: 12880290 DOI: 10.1023/a:1024462306941] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
PURPOSE The aim was to investigate the influence of polymer content and molecular weight on the morphology and heat- and moisture-induced transformations, as indicators of stability, of spray-dried composite particles of amorphous lactose and poly(vinylpyrrolidone) (PVP). METHODS Amorphous lactose and composite particles of amorphous lactose with different contents and molecular weights of PVP were prepared by spray drying. The nanostructure of the particles was analyzed by x-ray powder diffractometry, the morphology by light microscopy and SEM, the glass transition temperatures (Tg), crystallization temperatures (Tc), heats of crystallization and melting temperatures by differential scanning calorimetry, and moisture-induced crystallizations gravimetrically and by microcalorimetry. RESULTS All the types of particles prepared were amorphous. The Tg was unchanged or only marginally increased as a result of the inclusion of PVP. However, crystallization temperature, time to moisture-induced crystallization, and particle morphology were affected by both content and molecular weight of PVP. CONCLUSIONS Increased content and molecular weight of PVP may have the potential to increase the physical stability of amorphous lactose. However, Tg seems not to be a relevant indicator for the stability of this type of amorphous composite materials.
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Affiliation(s)
- Jonas Berggren
- Department of Pharmacy, Uppsala University, Box 580, SE-751 23 Uppsala, Sweden
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Aso Y, Yoshioka S, Zhang J, Zografi G. Effect of water on the molecular mobility of sucrose and poly(vinylpyrrolidone) in a colyophilized formulation as measured by (13)C-NMR relaxation time. Chem Pharm Bull (Tokyo) 2002; 50:822-6. [PMID: 12045339 DOI: 10.1248/cpb.50.822] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Individual molecular mobility of sucrose and poly(vinylpyrrolidone) (PVP) in a colyophilized mixture of 1 : 1 by weight has been determined by (13)C spin-lattice relaxation times in the laboratory frame (T(1)) and in the rotating frame (T(1 rho)) for systems containing absorbed water at various levels. The T(1) of the PVP pyrrolidone ring carbon increased with storage relative humidity (RH) in lyophilized PVP alone, indicating that the MHz-order motions of PVP side chain increased with storage RH. However, in the colyophilized mixture, the side chain motions of PVP did not change with storage RH, and showed similar mobility to sucrose. This may be caused by hydrogen bonding between the PVP ring carbonyl group and hydroxyl group of sucrose, as suggested by a previous FT-Raman study. The mid-kHz-order motions of sucrose in the sucrose-PVP mixture as determined by T(1 rho) did not increase with storage RH as much as in lyophilized sucrose alone. This suggests that the molecular mobility of sucrose decreases in the presence of PVP due to hydrogen bonding between the hydroxyl group of sucrose and the carbonyl group of PVP. Inhibition of sucrose crystallization by PVP in the presence of water appears to be linked to the effect of PVP on the molecular mobility of sucrose.
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Affiliation(s)
- Yukio Aso
- National Institute of Health Sciences, Setagaya, Tokyo, Japan
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