Influence of organic solvents on the habit of NMBA (4-nitro-4′-methyl benzylidene aniline) crystals

Srinivasan, K.; Sankaranarayanan, K.; Thangavelu, S.; Ramasamy, P.

doi:10.1016/s0022-0248(00)00300-6

Cited by 31 publications

(15 citation statements)

References 6 publications

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“…Absence of PEG 4000 and PVP K30 peaks was observed in the spectra of all samples. From the chemical structure of these polymers, hydroxyl groups of PEG 4000 and each pyrrolidone moiety of PVP exhibiting two groups (>N-and C=O) can be po- tentially hydrogen bonded with the amide (N-H) group or protonated pyridine N atom of piroxicam (10). Theoretically, there can be a chemical interaction between the drug and polymers.…”

Section: Ftirmentioning

confidence: 99%

“…However, recrystallized piroxicam displayed a better dissolution profile than the untreated form of piroxicam. The differences are due to the use of water-soluble hydrophilic polymers (4,8) forming a hydrophilic film on the surface of drug crystals, increasing the drug wettability and preventing drug aggregation, changing the crystallinity of piroxicam and giving rise to a form with a better dissolution rate (4,11,10,13).The presence of additives during the crystallization process might also cause a defect in the crystal structure and the crystal would become thermodynamically unstable and hence dissolve faster.…”

mentioning

confidence: 99%

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Crystal modifications and dissolution rate of piroxicam

Lyn¹,

Sze²,

Rajendran³

et al. 2011

Acta Pharmaceutica

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Crystal modifications and dissolution rate of piroxicam Piroxicam is a nonsteroidal anti-inflammatory drug with low aqueous solubility which exhibits polymorphism. The present study was carried out to develop polymorphs of piroxicam with enhanced solubility and dissolution rate by the crystal modification technique using different solvent mixtures prepared with PEG 4000 and PVP K30. Physicochemical characteristics of the modified crystal forms of piroxicam were investigated by X-ray powder diffractometry, FT-IR spectrophotometry and differential scanning calorimetry. Dissolution and solubility profiles of each modified crystal form were studied and compared with pure piroxicam. Solvent evaporation method (method I) produced both needle and cubic shaped crystals. Slow crystallization from ethanol with addition of PEG 4000 or PVP K30 at room temperature (method II) produced cubic crystal forms. Needle forms produced by method I improved dissolution but not solubility. Cubic crystals produced by method I had a dissolution profile similar to that of untreated piroxicam but showed better solubility than untreated piroxicam. Cubic shaped crystals produced by method II showed improved dissolution, without a significant change in solubility. Based on the XRPD results, modified piroxicam crystals obtained by method I from acetone/benzene were cube shaped, which correlates well with the FTIR spectrum; modified needle forms obtained from ethanol/methanol and ethanol/acetone showed a slight shift of FTIR peak that may be attributed to differences in the internal structure or conformation.

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Section: Ftirmentioning

confidence: 99%

mentioning

confidence: 99%

Crystal modifications and dissolution rate of piroxicam

Lyn¹,

Sze²,

Rajendran³

et al. 2011

Acta Pharmaceutica

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“…Solvents offering moderate solubility-temperature gradient for a material and yielding prismatic growth habit will be considered as suitable solvents for growing crystal of that material. Another important factor influencing the habit of growing crystal is the polarity of the solvents [3][4][5]. Table 1 presents the different electric dipole moments of solvents [6] employed in the present work and their influence on the growth habits of DBCH crystals.…”

Section: Choice Of Solventmentioning

confidence: 99%

Growth and characterization of 2,6‐dibenzylidenecyclohexanone single crystal

Lakshmi

Ramamurthi²

2005

Cryst. Res. Technol.

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Following the temperature reduction method, growth of single crystals of organic 2,6-dibenzylidenecyclohexanone (DBCH) material from ethanol solution is reported in the present work. Solubility and metastable zone width measurements were carried out under stirring and nonstirring conditions of solution. Cell dimensions were obtained from single crystal X-ray diffraction study. From FT-IR spectral analysis, various functional groups of this crystal were identified. UV-Visible spectral analysis was made. Mechanical strength of the grown crystal was estimated on the prominent (110) face using a Vickers microhardness tester.

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“…Due to their high bioactivities [1][2][3][4], heterogeneous or homogeneous catalysis [5][6][7] and interesting magnetic properties [8,9], Schiff base complexes formed from amino acids and carbonyl compounds have received much attention [10]. A large number of open-chain and macrocyclic multidentate ligand complexes have been investigated, with particular interest in their synthetic, thermodynamic and structural properties [11][12][13].…”

Section: Introductionmentioning

confidence: 99%

Synthesis, crystal structures and photocatalytic properties of Zn(II), Ni(II), Co(II) complexes with a symmetric open-chain N2O4-donor bis-Schiff base ligand

Wang

Zhang

et al. 2015

Transition Met Chem

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Three complexes, Zn(C 40 H 36 N 4 O 8 )Á3CH 3 OH (1), Ni(C 40 H 36 N 4 O 8 )Á3CH 3 OH (2) and Co(C 40 H 36 N 4 O 8 )Á3CH 3 OH (3), with a sexidentate (N 2 O 4 ) symmetric bis-Schiff base ligand (C 40 H 36 N 4 O 8 = 1,2-bis(2-methoxy-6-formylphenoxy) ethane-L-tryptophan) have been synthesized and characterized by physicochemical and spectroscopic methods. The X-ray crystal structures show that the metal atoms of three complexes are all six-coordinated by two nitrogens from C=N groups, two oxygens from ether groups and two carboxylic oxygens in the mono-ligand, forming a distorted octahedral geometry. The complexes were screened as photocatalysts for the degradation of methylene blue, rhodamine B and methyl violet. All three complexes proved to be good candidates for the photocatalytic degradation of methylene blue and complexes 2-3 are also good photocatalysts for the degradation of rhodamine B. The mechanism of these photocatalytic degradations is discussed.

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Influence of organic solvents on the habit of NMBA (4-nitro-4′-methyl benzylidene aniline) crystals

Cited by 31 publications

References 6 publications

Crystal modifications and dissolution rate of piroxicam

Crystal modifications and dissolution rate of piroxicam

Growth and characterization of 2,6‐dibenzylidenecyclohexanone single crystal

Synthesis, crystal structures and photocatalytic properties of Zn(II), Ni(II), Co(II) complexes with a symmetric open-chain N2O4-donor bis-Schiff base ligand

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