401
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Pajula K, Taskinen M, Lehto VP, Ketolainen J, Korhonen O. Predicting the Formation and Stability of Amorphous Small Molecule Binary Mixtures from Computationally Determined Flory−Huggins Interaction Parameter and Phase Diagram. Mol Pharm 2010; 7:795-804. [DOI: 10.1021/mp900304p] [Citation(s) in RCA: 121] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Katja Pajula
- School of Pharmacy and Department of Physics and Mathematics, University of Eastern Finland, P.O. Box 1627, FI-70211 Kuopio, Finland
| | - Markku Taskinen
- School of Pharmacy and Department of Physics and Mathematics, University of Eastern Finland, P.O. Box 1627, FI-70211 Kuopio, Finland
| | - Vesa-Pekka Lehto
- School of Pharmacy and Department of Physics and Mathematics, University of Eastern Finland, P.O. Box 1627, FI-70211 Kuopio, Finland
| | - Jarkko Ketolainen
- School of Pharmacy and Department of Physics and Mathematics, University of Eastern Finland, P.O. Box 1627, FI-70211 Kuopio, Finland
| | - Ossi Korhonen
- School of Pharmacy and Department of Physics and Mathematics, University of Eastern Finland, P.O. Box 1627, FI-70211 Kuopio, Finland
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402
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Li DX, Yan YD, Oh DH, Yang KY, Seo YG, Kim JO, Kim YI, Yong CS, Choi HG. Development of valsartan-loaded gelatin microcapsule without crystal change using hydroxypropylmethylcellulose as a stabilizer. Drug Deliv 2010; 17:322-9. [DOI: 10.3109/10717541003717031] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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403
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Janssens S, De Zeure A, Paudel A, Van Humbeeck J, Rombaut P, Van den Mooter G. Influence of Preparation Methods on Solid State Supersaturation of Amorphous Solid Dispersions: A Case Study with Itraconazole and Eudragit E100. Pharm Res 2010; 27:775-85. [DOI: 10.1007/s11095-010-0069-y] [Citation(s) in RCA: 100] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2009] [Accepted: 01/11/2010] [Indexed: 11/28/2022]
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404
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Sivert A, Bérard V, Andrès C. New binary solid dispersion of indomethacin with surfactant polymer: From physical characterization to in vitro dissolution enhancement. J Pharm Sci 2010; 99:1399-413. [DOI: 10.1002/jps.21935] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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405
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Ignatious F, Sun L, Lee CP, Baldoni J. Electrospun Nanofibers in Oral Drug Delivery. Pharm Res 2010; 27:576-88. [DOI: 10.1007/s11095-010-0061-6] [Citation(s) in RCA: 88] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2009] [Accepted: 01/06/2010] [Indexed: 10/19/2022]
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406
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Rumondor ACF, Taylor LS. Effect of Polymer Hygroscopicity on the Phase Behavior of Amorphous Solid Dispersions in the Presence of Moisture. Mol Pharm 2010; 7:477-90. [DOI: 10.1021/mp9002283] [Citation(s) in RCA: 140] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Alfred C. F. Rumondor
- Department of Industrial and Physical Pharmacy, School of Pharmacy, Purdue University, West Lafayette, Indiana 47907, and Pharmaceutical Development, AstraZeneca Pharmaceuticals LP, Wilmington, Delaware, 19850
| | - Lynne S. Taylor
- Department of Industrial and Physical Pharmacy, School of Pharmacy, Purdue University, West Lafayette, Indiana 47907, and Pharmaceutical Development, AstraZeneca Pharmaceuticals LP, Wilmington, Delaware, 19850
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407
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Abstract
Abstract
Objectives
With poorly soluble drug candidates emerging in the drug discovery pipeline, the importance of the solid dispersion formulation approach is increasing. This strategy includes complete removal of drug crystallinity, and molecular dispersion of the poorly soluble compound in a hydrophilic polymeric carrier. The potential of this technique to increase oral absorption and hence bioavailability is enormous. Nevertheless, some issues have to be considered regarding thermodynamic instability, as well in supersaturated solutions that are formed upon dissolution as in the solid state.
Key findings
After a brief discussion on the historical background of solid dispersions and their current role in formulation, an overview will be given on the physical chemistry and stability of glass solutions as they form supersaturated solutions, and during their shelf life.
Conclusions
Thorough understanding of these aspects will elicit conscious evaluation of carrier properties and eventually facilitate rational excipient selection. Thus, full exploitation of the solid dispersion strategy may provide an appropriate answer to drug attrition due to low aqueous solubility in later stages of development.
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Affiliation(s)
- Sandrien Janssens
- Laboratorium voor Farmacotechnologie en Biofarmacie, Katholieke Universiteit Leuven, Leuven, Belgium
| | - Guy Van den Mooter
- Laboratorium voor Farmacotechnologie en Biofarmacie, Katholieke Universiteit Leuven, Leuven, Belgium
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408
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Marsac PJ, Rumondor AC, Nivens DE, Kestur US, Stanciu L, Taylor LS. Effect of temperature and moisture on the miscibility of amorphous dispersions of felodipine and poly(vinyl pyrrolidone). J Pharm Sci 2010; 99:169-85. [DOI: 10.1002/jps.21809] [Citation(s) in RCA: 157] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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409
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Rumondor ACF, Stanford LA, Taylor LS. Effects of Polymer Type and Storage Relative Humidity on the Kinetics of Felodipine Crystallization from Amorphous Solid Dispersions. Pharm Res 2009; 26:2599-606. [DOI: 10.1007/s11095-009-9974-3] [Citation(s) in RCA: 133] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2009] [Accepted: 09/14/2009] [Indexed: 11/24/2022]
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410
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Kluge J, Fusaro F, Mazzotti M, Muhrer G. Production of PLGA micro- and nanocomposites by supercritical fluid extraction of emulsions: II. Encapsulation of Ketoprofen. J Supercrit Fluids 2009. [DOI: 10.1016/j.supflu.2009.05.002] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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411
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An improved kinetics approach to describe the physical stability of amorphous solid dispersions. Int J Pharm 2009; 384:24-31. [PMID: 19786081 DOI: 10.1016/j.ijpharm.2009.09.035] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2009] [Revised: 09/04/2009] [Accepted: 09/18/2009] [Indexed: 11/21/2022]
Abstract
The recrystallization of amorphous solid dispersions may lead to a loss in the dissolution rate, and consequently reduce bioavailability. The purpose of this work is to understand factors governing the recrystallization of amorphous drug-polymer solid dispersions, and develop a kinetics model capable of accurately predicting their physical stability. Recrystallization kinetics was measured using differential scanning calorimetry for initially amorphous efavirenz-polyvinylpyrrolidone solid dispersions stored at controlled temperature and relative humidity. The experimental measurements were fitted by a new kinetic model to estimate the recrystallization rate constant and microscopic geometry of crystal growth. The new kinetics model was used to illustrate the governing factors of amorphous solid dispersions stability. Temperature was found to affect efavirenz recrystallization in an Arrhenius manner, while recrystallization rate constant was shown to increase linearly with relative humidity. Polymer content tremendously inhibited the recrystallization process by increasing the crystallization activation energy and decreasing the equilibrium crystallinity. The new kinetic model was validated by the good agreement between model fits and experiment measurements. A small increase in polyvinylpyrrolidone resulted in substantial stability enhancements of efavirenz amorphous solid dispersion. The new established kinetics model provided more accurate predictions than the Avrami equation.
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412
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Kawakami K. Current status of amorphous formulation and other special dosage forms as formulations for early clinical phases. J Pharm Sci 2009; 98:2875-85. [DOI: 10.1002/jps.21816] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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413
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Saylor DM, Kim CS, Patwardhan DV, Warren JA. Modeling microstructure development and release kinetics in controlled drug release coatings. J Pharm Sci 2009; 98:169-86. [PMID: 18481310 DOI: 10.1002/jps.21416] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
In recent years, controlled release coatings, comprised of drug-polymer composites, have been integrated with medical devices, improving device functionality and performance. However, relationships between material properties, manufacturing environment, composite (micro)structure, and subsequent release kinetics are not well established. We apply a thermodynamically consistent model to probe the influence of drug-polymer chemistry (phobicity), drug loading, and evaporation rate on microstructure development during fabrication. For these structures, we compute release profiles for exposure to polymer-insoluble media and media in which the polymer readily dissolves. We find that with increasing drug-polymer phobicity, structural heterogeneities form at lower loadings and more rapid rates. The heterogeneities remain isolated and compact at low loadings and become interconnected as the drug to polymer ratio approaches 1.0. Release into polymer-insoluble media was dramatically enhanced by heterogeneities, resulting in up to a fourfold increase in drug release. In polymer-soluble media, however, heterogeneities diminished release. Although reductions of only 30% were typically observed, the absolute changes were much larger than observed in polymer-insoluble media. Our results suggest that improved comprehension and quantification of the physico-chemical properties in controlled release systems will enable the microstructure to be tailored to achieve desired responses that are insensitive to manufacturing variations.
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Affiliation(s)
- David M Saylor
- Food and Drug Administration, Center for Devices and Radiological Health, Office of Science and Engineering Laboratories, Silver Spring, Maryland 20903, USA.
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414
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415
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Intraorally fast-dissolving particles of a poorly soluble drug: Preparation and in vitro characterization. Eur J Pharm Biopharm 2009; 71:271-81. [DOI: 10.1016/j.ejpb.2008.09.001] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2008] [Revised: 08/18/2008] [Accepted: 09/02/2008] [Indexed: 11/20/2022]
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416
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Haddadin R, Qian F, Desikan S, Hussain M, Smith RL. Estimation of Drug Solubility in Polymers via Differential Scanning Calorimetry and Utilization of the Fox Equation. Pharm Dev Technol 2008; 14:18-26. [DOI: 10.1080/10837450802409370] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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417
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Tao J, Sun Y, Zhang GGZ, Yu L. Solubility of Small-Molecule Crystals in Polymers: d-Mannitol in PVP, Indomethacin in PVP/VA, and Nifedipine in PVP/VA. Pharm Res 2008; 26:855-64. [DOI: 10.1007/s11095-008-9784-z] [Citation(s) in RCA: 166] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2008] [Accepted: 11/04/2008] [Indexed: 11/30/2022]
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418
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Janssens S, Denivelle S, Rombaut P, Van den Mooter G. Influence of polyethylene glycol chain length on compatibility and release characteristics of ternary solid dispersions of itraconazole in polyethylene glycol/hydroxypropylmethylcellulose 2910 E5 blends. Eur J Pharm Sci 2008; 35:203-10. [DOI: 10.1016/j.ejps.2008.06.014] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2008] [Revised: 05/26/2008] [Accepted: 06/26/2008] [Indexed: 11/25/2022]
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419
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Marsac PJ, Li T, Taylor LS. Estimation of drug-polymer miscibility and solubility in amorphous solid dispersions using experimentally determined interaction parameters. Pharm Res 2008; 26:139-51. [PMID: 18779927 DOI: 10.1007/s11095-008-9721-1] [Citation(s) in RCA: 369] [Impact Index Per Article: 23.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2008] [Accepted: 08/27/2008] [Indexed: 01/15/2023]
Abstract
PURPOSE The amorphous form of a drug may provide enhanced solubility, dissolution rate, and bioavailability but will also potentially crystallize over time. Miscible polymeric additives provide a means to increase physical stability. Understanding the miscibility of drug-polymer systems is of interest to optimize the formulation of such systems. The purpose of this work was to develop experimental models which allow for more quantitative estimates of the thermodynamics of mixing amorphous drugs with glassy polymers. MATERIALS AND METHODS The thermodynamics of mixing several amorphous drugs with amorphous polymers was estimated by coupling solution theory with experimental data. The entropy of mixing was estimated using Flory-Huggins lattice theory. The enthalpy of mixing and any deviations from the entropy as predicted by Flory-Huggins lattice theory were estimated using two separate experimental techniques; (1) melting point depression of the crystalline drug in the presence of the amorphous polymer was measured using differential scanning calorimetry and (2) determination of the solubility of the drug in 1-ethyl-2-pyrrolidone. The estimated activity coefficient was used to calculate the free energy of mixing of the drugs in the polymers and the corresponding solubility. RESULTS Mixtures previously reported as miscible showed various degrees of melting point depression while systems reported as immiscible or partially miscible showed little or no melting point depression. The solubility of several compounds in 1-ethyl-2-pyrrolidone predicts that most drugs have a rather low solubility in poly(vinylpyrrolidone). CONCLUSIONS Miscibility of various drugs with polymers can be explored by coupling solution theories with experimental data. These approximations provide insight into the physical stability of drug-polymer mixtures and the thermodynamic driving force for crystallization.
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Affiliation(s)
- Patrick J Marsac
- Materials Characterization and Technology Assessment, Merck & Co., Inc., West Point, Pennsylvania 19486, USA
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420
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Chow K, Tong HH, Lum S, Chow AH. Engineering of Pharmaceutical Materials: An Industrial Perspective. J Pharm Sci 2008; 97:2855-77. [DOI: 10.1002/jps.21212] [Citation(s) in RCA: 105] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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421
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Janssens S, de Armas HN, Roberts CJ, Van den Mooter G. Characterization of Ternary Solid Dispersions of Itraconazole, PEG 6000, and HPMC 2910 E5. J Pharm Sci 2008; 97:2110-20. [PMID: 17847067 DOI: 10.1002/jps.21128] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
In order to reduce the crystallinity of PEG 6000, blends were prepared by spray drying and extrusion with the following polymers; PVP K25, PVPVA 64, and HPMC 2910 E5. The maximal reduction of crystallinity in PEG 6000 was obtained by co-spray drying with HPMC 2910 E5. In the next step the model drug Itraconazole was added to the blend and the resulting ternary solid dispersions were characterized. The results of this study show that the addition of PEG 6000 to the Itraconazole/HPMC 2910 E5 system leads to phase separation that in most cases gives rise to recrystallization of either PEG 6000 or Itraconazole. For all ternary dispersions containing 20% of Itraconazole the drug was highly amorphous and the dissolution was improved compared to the binary 20/80 w/w Itraconazole/HPMC 2910 E5 solid dispersion. For all ternary dispersions containing 40% of Itraconazole, the drug was partially crystalline and the dissolution was lower than the dissolution of the binary 40/60 w/w Itraconazole/HPMC 2910 E5 dispersion. These results show that provided Itraconazole is highly amorphous the addition of PEG 6000 to HPMC 2910 E5 leads to an increase in drug release.
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Affiliation(s)
- Sandrien Janssens
- Laboratorium voor Farmacotechnologie en Biofarmacie, K.U.Leuven, Leuven, Belgium
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422
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Marsac PJ, Konno H, Rumondor ACF, Taylor LS. Recrystallization of Nifedipine and Felodipine from Amorphous Molecular Level Solid Dispersions Containing Poly(vinylpyrrolidone) and Sorbed Water. Pharm Res 2007; 25:647-56. [PMID: 17846870 DOI: 10.1007/s11095-007-9420-3] [Citation(s) in RCA: 71] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2007] [Accepted: 07/26/2007] [Indexed: 10/22/2022]
Abstract
PURPOSE To compare the physical stability of amorphous molecular level solid dispersions of nifedipine and felodipine, in the presence of poly(vinylpyrrolidone) (PVP) and small amounts of moisture. METHODS Thin amorphous films of nifedipine and felodipine and amorphous molecular level solid dispersions with PVP were stored at various relative humidities (RH) and the nucleation rate was measured. The amount of water sorbed at each RH was measured using isothermal vapor sorption and glass transition temperatures (Tg) were determined using differential scanning calorimetry. The solubility of each compound in methyl pyrrolidone was measured as a function of water content. RESULTS Nifedipine crystallizes more easily than felodipine at any given polymer concentration and in the presence of moisture. The glass transition temperatures of each compound, alone and in the presence of PVP, are statistically equivalent at any given water content. The nifedipine systems are significantly more hygroscopic than the corresponding felodipine systems. CONCLUSIONS Variations in the physical stability of the two compounds could not be explained by differences in Tg. However, the relative physical stability is consistent with differences in the degree of supersaturation of each drug in the solid dispersion, treating the polymer and water as a co-solvent system for each drug compound.
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Affiliation(s)
- Patrick J Marsac
- Department of Industrial and Physical Pharmacy, School of Pharmacy, Purdue University, West Lafayette, Indiana, 47907 USA
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423
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Aso Y, Yoshioka S, Miyazaki T, Kawanishi T, Tanaka K, Kitamura S, Takakura A, Hayashi T, Muranushi N. Miscibility of Nifedipine and Hydrophilic Polymers as Measured by 1H-NMR Spin-Lattice Relaxation. Chem Pharm Bull (Tokyo) 2007; 55:1227-31. [PMID: 17666850 DOI: 10.1248/cpb.55.1227] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The miscibility of a drug with excipients in solid dispersions is considered to be one of the most important factors for preparation of stable amorphous solid dispersions. The purpose of the present study was to elucidate the feasibility of (1)H-NMR spin-lattice relaxation measurements to assess the miscibility of a drug with excipients. Solid dispersions of nifedipine with the hydrophilic polymers poly(vinylpyrrolidone) (PVP), hydroxypropylmethylcellulose (HPMC) and alpha,beta-poly(N-5-hydroxypentyl)-L-aspartamide (PHPA) with various weight ratios were prepared by spray drying, and the spin-lattice relaxation decay of the solid dispersions in a laboratory frame (T(1) decay) and in a rotating frame (T(1rho) decay) were measured. T(1rho) decay of nifedipine-PVP solid dispersions (3 : 7, 5 : 5 and 7 : 3) was describable with a mono-exponential equation, whereas T(1rho) decay of nifedipine-PHPA solid dispersions (3 : 7, 4 : 6 and 5 : 5) was describable with a bi-exponential equation. Because a mono-exponential T(1rho) decay indicates that the domain sizes of nifedipine and polymer in solid dispersion are less than several nm, it is speculated that nifedipine is miscible with PVP but not miscible with PHPA. All the nifedipine-PVP solid dispersions studied showed a single glass transition temperature (T(g)), whereas two glass transitions were observed for the nifedipine-PHPA solid dispersion (3 : 7), thus supporting the above speculation. For nifedipine-HPMC solid dispersions (3 : 7 and 5 : 5), the miscibility of nifedipine and HPMC could not be determined by DSC measurements due to the lack of obviously evident T(g). In contrast, (1)H-NMR spin-lattice relaxation measurements showed that nifedipine and HPMC are miscible, since T(1rho) decay of the solid dispersions (3 : 7, 5 : 5 and 7 : 3) was describable with a mono-exponential equation. These results indicate that (1)H-NMR spin-lattice relaxation measurements are useful for assessing the miscibility of a drug and an excipient in solid dispersions.
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Affiliation(s)
- Yukio Aso
- National Institute of Health Sciences, Tokyo, Japan.
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424
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Marsac PJ, Konno H, Taylor LS. A Comparison of the Physical Stability of Amorphous Felodipine and Nifedipine Systems. Pharm Res 2006; 23:2306-16. [PMID: 16927182 DOI: 10.1007/s11095-006-9047-9] [Citation(s) in RCA: 215] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2006] [Accepted: 05/01/2006] [Indexed: 11/28/2022]
Abstract
PURPOSE The objective of this study was to investigate thermodynamic and kinetic factors contributing to differences in the isothermal nucleation rates of two structurally related calcium channel blockers, nifedipine and felodipine, both alone and in the presence of poly(vinylpyrrolidone) (PVP). MATERIALS AND METHODS Thin films of amorphous systems were cast onto glass slides and the nucleation rate was determined using optical microscopy. Enthalpy, entropy, and free energy of crystallization of the pure compounds were measured using differential scanning calorimetery (DSC). Molecular mobility and glass transition temperature of each amorphous system were characterized using DSC and hydrogen bonding patterns were analyzed with infrared spectroscopy. The composition dependence of the thermodynamic activity of the amorphous drug in the presence of the polymer was estimated using Flory-Huggins lattice theory. RESULTS Nifedipine crystallized more readily than felodipine from the metastable amorphous form both alone and in the presence of PVP despite having a similar glass transition temperature and molecular mobility. Nifedipine was found to have a larger enthalpic driving force for crystallization and a lower activation energy for nucleation. CONCLUSIONS The properties of the metastable form alone did not explain the greater propensity for nifedipine crystallization. When considering the physical stability of amorphous systems, it is important to also consider the properties of the crystalline counterpart.
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Affiliation(s)
- Patrick J Marsac
- Department of Industrial and Physical Pharmacy, School of Pharmacy, Purdue University, West Lafayette, Indiana 47907, USA
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