Structure of the anti-inflammatory drug 4-hydroxy-2-methyl-N-2-pyridyl-2H-1λ6,2-benzothiazine-3-carboxamide 1,1-dioxide (piroxicam)

Kojić‐Prodić, Biserka; Ružić‐Toroš, Ž.

doi:10.1107/s0567740882010450

Cited by 90 publications

(78 citation statements)

References 1 publication

Supporting

Mentioning

Contrasting

Order By: Relevance

“…32 For (1), the X-ray structure was in excellent agreement with results reported by Koji-Prodic et al 36 in 1982, and also correlate well with the optimised geometry model (OPT), with mean differences of 0.006 Å and 0.4° for bond lengths and angles, respectively. A similar situation was also seen for (2), where the geometrical details…”

Section: Geometrysupporting

confidence: 82%

An analysis of the experimental and theoretical charge density distributions of the piroxicam–saccharin co-crystal and its constituents

Váradi

Williams

et al. 2016

RSC Adv.

View full text Add to dashboard Cite

Experimental and theoretical charge density analyses of piroxicam (1), saccharin (2) and their 1:1 co-crystal complex (3) have been carried out. Electron density distribution (EDD) was determined through the use of high-resolution single crystal X-ray diffraction and the data were modelled using the conventional multipole model of electron density according to the Hansen-Coppens formalism. A method for optimising the core density refinement of sulfur atoms is discussed, with emphasis on the reduction of residual electron density that is typically associated with this atom. The asymmetric unit of complex (3) contains single molecules of saccharin and the zwitterionic form of piroxicam. These are held together by weak interactions (hydrogen bonds, π-π and van der Waals interactions), ranging in strength from 4 to 160 kJmol -1 , working together to stabilise the complex;. analysis of the molecular electrostatic potential (MEP) of the complexes showed electron redistribution within the cocrystal, facilitating the formation of these generally weak interactions. Interestingly, in the zwitterionic form of piroxicam, the charge distribution reveals that the positive and negative charges are not associated with the formal charges normally associated with this description, but are distributed over adjacent molecular fragments. The use of anisotropic displacement parameters (ADPs) for hydrogen atoms in the multipole model was also investigated but no improvement in the quality of the topological analysis was found.3

show abstract

Section: Geometrysupporting

confidence: 82%

An analysis of the experimental and theoretical charge density distributions of the piroxicam–saccharin co-crystal and its constituents

Váradi

Williams

et al. 2016

RSC Adv.

View full text Add to dashboard Cite

show abstract

“…The measurements of a sample obtained were taken by a Rigku Model ROTAFLEX Ru-200. The space group of Pir (monoclinic P2 1 /C) is determined with Cu Ka radiation and the cell parameters [41] were defined from diffractometer measurements: a ¼ 7:127 (4), b ¼ 15:136 (8), c ¼ 13.949 (17) Å , b ¼ 97: 35 (2)8, Z ¼ 4. The Pir molecule is not far from being planar ($bc plane) [42].…”

Section: X-ray Powder Diffractionmentioning

confidence: 99%

Preparation and spectroscopic characterisation of metal complexes of piroxicam

Gehad

Nadia

2004

Vibrational Spectroscopy

View full text Add to dashboard Cite

“…Of the eight PX complexes (for convenience, the shorthand "complexes" is adopted as a shorthand nomenclature for the term multi-component molecular crystals in some of the discussion below) with NHCs, transfer of the PX hydroxyl hydrogen to the NHC to form the deprotonated PX¯ occurs in five (1)(2)(3)(4)(5). Three of these are solvated complexes with imidazole (IM), which all feature protonation of the IM.…”

Section: Multi-component Molecular Crystals Of Piroxicam With Nheteromentioning

confidence: 99%

“…Molecular complexes from cocrystallisation experiments are seen as an increasingly useful tool in the preparation of solid forms of active pharmaceutical ingredients (APIs), with molecular complexes of pharmaceuticals not only having the potential to be patented as new materials 2 , but also for improving the physicochemical properties of an API without compromising the structural integrity 3 . Piroxicam (PX) is a non-steroidal anti-inflammatory drug (NSAID) that has been extensively studied in the solid state [4][5][6][7][8][9][10][11] . Presented here are further investigations of multicomponent molecular crystals of this important API, with particular regard to the crystal engineering potential and the potential modification of relevant physical properties of the multi-component crystals formed, with respect to those of the parent material.…”

Section: Introductionmentioning

confidence: 99%

Intermolecular hydrogen transfer and solubility tuning in multi-component molecular crystals of the API piroxicam

et al. 2014

View full text Add to dashboard Cite

Please cite only the published version using the reference above.See http://opus.bath.ac.uk/ for usage policies.Please scroll down to view the document. CrystEngComm RSCPublishing ARTICLEThis journal is © The Royal Society of Chemistry 2013 J. Name., 2013, 00, 1-3 | 1 A series of twelve multi-component molecular crystals of the active pharmaceutical ingredient (API) piroxicam (PX) have been synthesised and their structures analysed with respect to their supramolecular motifs and degree of intermolecular hydrogen transfer observed on formation of the various complexes. The multi-component crystals of PX formed with a series of basic N-heterocycles are contrasted with those formed with strong haloanilic acids, with PX found to adopt different ionisation states. The effect of the formation of these multi-component molecular crystals on the physical property of solubility, often crucial in API formulation, has been investigated and these solubility determinations are compared with those of the parent PX material. Enhanced solubility is evident in some of the multi-component crystals formed. IntroductionMulti-component crystallisation -also referred to as cocrystallisation -is the method of bringing together two or more different molecules into the same crystal lattice to form a molecular complex or salt 1 . Molecular complexes from cocrystallisation experiments are seen as an increasingly useful tool in the preparation of solid forms of active pharmaceutical ingredients (APIs), with molecular complexes of pharmaceuticals not only having the potential to be patented as new materials 2 , but also for improving the physicochemical properties of an API without compromising the structural integrity 3 . Piroxicam (PX) is a non-steroidal anti-inflammatory drug (NSAID) that has been extensively studied in the solid state [4][5][6][7][8][9][10][11] . Presented here are further investigations of multicomponent molecular crystals of this important API, with particular regard to the crystal engineering potential and the potential modification of relevant physical properties of the multi-component crystals formed, with respect to those of the parent material. In terms of the crystal engineering aspects, the aim is to identify robust synthons which may be utilised for future design of molecular complexes of piroxicam, while the particular physical property under investigation here is that of solubility, relevant to a wide range of APIs in seeking to develop their optimized formulation in manufacturing and processing of pharmaceutical products. In the solid state, piroxicam has previously been shown to exist in two ionisation states when not in its neutral form. While pure piroxicam exists in the non-ionised form in the solid state, it has been shown that in polar solvents, such as acetonitrile which is commonly used in crystallisation experiments with piroxicam, the zwitterionic form is present in large quantities 12,13 . The formation of the zwitterion, through intramolecular hydrogen-transfer, has been observed in solvates and ...

show abstract

Structure of the anti-inflammatory drug 4-hydroxy-2-methyl-N-2-pyridyl-2H-1λ⁶,2-benzothiazine-3-carboxamide 1,1-dioxide (piroxicam)

Cited by 90 publications

References 1 publication

An analysis of the experimental and theoretical charge density distributions of the piroxicam–saccharin co-crystal and its constituents

An analysis of the experimental and theoretical charge density distributions of the piroxicam–saccharin co-crystal and its constituents

Preparation and spectroscopic characterisation of metal complexes of piroxicam

Intermolecular hydrogen transfer and solubility tuning in multi-component molecular crystals of the API piroxicam

Contact Info

Product

Resources

About