Characterization of Inter- and Intramolecular Hydrogen Bonding in the Solid State Using Variable-Temperature IR Spectroscopy

Slootmaekers, B.; Desseyn, H. O.

doi:10.1366/0003702914337876

Cited by 26 publications

(14 citation statements)

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“…16,21 When analyzed in a non-polar solvent, the position of the NH stretching vibration should not change upon dilution if intramolecular hydrogen bond formation occurs whereas for intermolecular hydrogen the NH peak will shift with dilution. 22,23 The NH peak position was consistently seen at 3345 cm À1 over the concentration range 1-100 mg ml À1 in dichloromethane (Figure S 1). This peak position is consistent with a hydrogen bonded NH peak and therefore it can be concluded that nimesulide forms an intramolecular hydrogen bond in solution.…”

Section: Discussionmentioning

confidence: 89%

Influence of polymer chemistry on crystal growth inhibition of two chemically diverse organic molecules

2011

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The purpose of this study was to understand how different polymers affect the crystal growth rates of two chemically diverse organic drug molecules (bifonazole and nimesulide) from the undercooled melt regime close to the glass transition temperature. Bifonazole is an antifungal drug that contains no traditional hydrogen bond donors, only acceptors. In contrast, nimesulide contains both hydrogen bond donor and acceptor groups. Therefore, the potential hydrogen bonding interactions with polymers vary between the two compounds. For bifonazole, poly(vinylpyrrolidone) (PVP), hydroxypropyl methylcellulose acetate succinate (HPMCAS), poly(vinylpyrrolidone-vinyl acetate) (PVP/VA) and poly(acrylic acid) (PAA) were investigated, while for nimesulide, PVP, PVP/VA and poly(vinyl acetate) (PVAc) were probed. Polymers were incorporated at a level of 5%w/w by cryomilling followed by melt quenching. Linear crystal growth rates in the presence and absence of polymers were measured as a function of temperature (18-100 C for bifonazole and 18-80 C for nimesulide) using optical microscopy. Differential scanning calorimetry (DSC) and infrared spectroscopy were performed for further characterization. All of the polymers decreased the growth rates of both drugs, however large differences could be observed between polymers in terms of the extent of crystal growth inhibition. For bifonazole, PAA was a notably better crystal growth inhibitor compared to the other polymers. This may be related to formation of specific interactions between the drug and the polymer. For nimesulide, the order of effectiveness was PVP$PVP/VA>PVAc and, compared to bifonazole, differences seen between polymers were more modest. Infrared (IR) spectroscopy and density functional calculations strongly suggested that amorphous nimesulide formed an intramolecular hydrogen bond. IR spectroscopy showed that drug-polymer intermolecular hydrogen bonding did occur, but was hampered by the partial loss of the hydrogen bond donor to the intramolecular hydrogen bond. Hence the effectiveness of a polymer appears to depend not only on the chemistry of the drug, but also on the availability of hydrogen bonding groups.

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Section: Discussionmentioning

confidence: 89%

Influence of polymer chemistry on crystal growth inhibition of two chemically diverse organic molecules

2011

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“…For each spectrum 200 scans were recorded and averaged. These measurements were performed with a laboratory designed liquid nitrogen cooled cryostat, 45 consisting of a copper sample holder with a small container which can be filled with liquid nitrogen. This is surrounded by a jacket with KBr windows and placed under vacuum.…”

Section: Methodsmentioning

confidence: 99%

Solids Modeled by Ab-Initio Crystal Field Methods. Part 17. Study of the Structure and Vibrational Spectrum of Urea in the Gas Phase and in Its P4̄2₁m Crystal Phase

Rousseau¹,

Alsenoy²,

Keuleers³

et al. 1998

J. Phys. Chem. A

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In this study the geometrical structure and vibrational spectrum are studied for the urea molecule (CO(NH2)2) in the gas phase as well as in its P4̄21 m crystal phase. Experimental frequencies for urea in the crystal phase are determined for the CO(NH2)2, C18O(NH2)2, CO(15NH2)2, 13CO(NH2)2, CO(ND2)2, C18O(ND2)2, CO(15ND2)2, and 13CO(ND2)2 isotopomers. Using calculations at the RHF/6-31++G** level, the equilibrium geometry and harmonic force field for both the gas phase and the crystal phase are determined. The crystal phase is modeled using a 15 molecule cluster surrounded by 5312 point charges. Calculated structure and frequencies are in excellent agreement with experiment. Shifts in frequencies for the above-mentioned isotopomers are reproduced with a root mean square deviation and largest difference of 15 and 43 cm-1, respectively. Shifts in frequencies in going from the gas phase to the crystal phase for the parent and deuterated isotopomer are reproduced with a root mean square deviation and largest difference of 14 and 31 cm-1, respectively.

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“…Vibrational spectroscopy offers the possibility of gaining a molecular-level view (possibly H-bond interactions) of the macroscopic changes that occur in crystalline and amorphous materials as they are heated. 23 On heating, as T g is approached, the specific volume begins to increase more rapidly because of a larger thermal expansion coefficient in the liquid than in the glassy state, which has a similar behavior to that for the crystalline state. 24 These volume differences affect intermolecular distances and, hence, intermolecular interactions.…”

Section: Effect Of Thermal Stressmentioning

confidence: 97%

Devitrification of amorphous celecoxib

Gupta

Bansal

2005

AAPS PharmSciTech

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The purpose of this research was to analyze the devitrification of amorphous celecoxib (CEL) in the presence of different stressors (temperature, pressure, and/or humidity) encountered during processing of solid dosage forms. Amorphous CEL was prepared in situ in the analytical instruments, as well as in laboratory, by quench-cooling of melt process, and analyzed by dynamic mechanical thermal analysis, differential scanning calorimetry, microscopy, and Fourier-transform infrared spectroscopy. Amorphous CEL prepared in situ in the analytical instruments was resistant to crystallization under the influence of temperature and/or pressure, because of its protection from the external environment during preparation. These samples exhibited structural relaxation during annealing at 25 degrees C/0% relative humidity (RH) for 16 hours. Generation of amorphous CEL in the laboratory resulted in partially crystalline samples, because of exposure to environmental temperature and humidity, resulting in incomplete vitrification. Subjection to thermal stress favored crystallization of amorphous CEL into metastable polymorphic forms, which were not obtained by solvent recrystallization approach. Temperature and humidity were identified as the major factors promoting devitrification of amorphous CEL, leading to loss of solubility advantage. Exposure to International Conference on Harmonization-specified accelerated stability storage conditions (40 degrees C/75% RH) resulted in complete devitrification of amorphous CEL within 15 days. The phase-transformation process of amorphous CEL along the temperature scale was examined visually, as well as spectrally. This propensity for devitrification of amorphous CEL seemed to depend on the strength of differential molecular interactions between the amorphous and crystalline form.

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Characterization of Inter- and Intramolecular Hydrogen Bonding in the Solid State Using Variable-Temperature IR Spectroscopy

Cited by 26 publications

References 1 publication

Influence of polymer chemistry on crystal growth inhibition of two chemically diverse organic molecules

Influence of polymer chemistry on crystal growth inhibition of two chemically diverse organic molecules

Solids Modeled by Ab-Initio Crystal Field Methods. Part 17. Study of the Structure and Vibrational Spectrum of Urea in the Gas Phase and in Its P4̄2₁m Crystal Phase

Devitrification of amorphous celecoxib

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Characterization of Inter- and Intramolecular Hydrogen Bonding in the Solid State Using Variable-Temperature IR Spectroscopy

Cited by 26 publications

References 1 publication

Influence of polymer chemistry on crystal growth inhibition of two chemically diverse organic molecules

Influence of polymer chemistry on crystal growth inhibition of two chemically diverse organic molecules

Solids Modeled by Ab-Initio Crystal Field Methods. Part 17. Study of the Structure and Vibrational Spectrum of Urea in the Gas Phase and in Its P4̄21m Crystal Phase

Devitrification of amorphous celecoxib

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Product

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Solids Modeled by Ab-Initio Crystal Field Methods. Part 17. Study of the Structure and Vibrational Spectrum of Urea in the Gas Phase and in Its P4̄2₁m Crystal Phase