Effect of pH, polymer concentration and molecular weight on the physical state properties of tolfenamic acid

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Effect of pH, polymer concentration and molecular weight on the physical state properties of tolfenamic acid. / Sheraz, M.A.; Ahmed, S.; Rehman, I.U.
In: Pharmaceutical Development and Technology, Vol. 20, No. 3, 2015, p. 352-360.

Research output: Contribution to Journal/Magazine › Journal article › peer-review

Harvard

Sheraz, MA, Ahmed, S & Rehman, IU 2015, 'Effect of pH, polymer concentration and molecular weight on the physical state properties of tolfenamic acid', Pharmaceutical Development and Technology, vol. 20, no. 3, pp. 352-360. https://doi.org/10.3109/10837450.2013.871027

APA

Sheraz, M. A., Ahmed, S., & Rehman, I. U. (2015). Effect of pH, polymer concentration and molecular weight on the physical state properties of tolfenamic acid. Pharmaceutical Development and Technology, 20(3), 352-360. https://doi.org/10.3109/10837450.2013.871027

Vancouver

Sheraz MA, Ahmed S, Rehman IU. Effect of pH, polymer concentration and molecular weight on the physical state properties of tolfenamic acid. Pharmaceutical Development and Technology. 2015;20(3):352-360. doi: 10.3109/10837450.2013.871027

Author

Sheraz, M.A. ; Ahmed, S. ; Rehman, I.U. / Effect of pH, polymer concentration and molecular weight on the physical state properties of tolfenamic acid. In: Pharmaceutical Development and Technology. 2015 ; Vol. 20, No. 3. pp. 352-360.

Bibtex

@article{e13f30d394c84988872934dde3a6a8dd,

title = "Effect of pH, polymer concentration and molecular weight on the physical state properties of tolfenamic acid",

abstract = "Tolfenamic acid (TA) has been transformed from crystalline to amorphous state through freeze-drying by using varying ratios of polyacrylic acid (PA) at various pH values. The characterization of the films has been carried out using X-ray diffraction, differential scanning calorimetry, Fourier transform infrared (FTIR) spectrometry and scanning electron microscopy. The results showed a gradual change in the solid state properties of TA and a complete transformation into its amorphous form in 1:8, 1:4, 1:2 and 1:1 ratios at pH 3, 4, 5 and 6, respectively. FTIR spectrometry reveals the formation of a yellow polymorphic form of TA. Polymer molecular weight has also been observed to affect the drug transformation and interaction as the low molecular weight PA (Mw ∼ 1800) was found to be most effective followed by its medium (Mv ∼ 450 000) and high molecular weight (Mv ∼ 3 000 000) forms. No signs of recrystallization in the TA-PA films were noted during the 12-week storage period. PA of low molecular weight has also been found more effective in inhibiting the recrystallization of the melt upon cooling thus proving a valuable polymer in producing stable amorphous solid dispersions of TA. {\textcopyright} 2015 Informa Healthcare USA, Inc.",

keywords = "Amorphous, Characterization, Freeze-drying, Polyacrylic acid, Recrystallization, polymer, tolfenamic acid, acrylic acid resin, anthranilic acid derivative, carbopol 940, nonsteroid antiinflammatory agent, Article, crystallization, differential scanning calorimetry, drug solubility, drug structure, drug transformation, freeze drying, infrared spectroscopy, molecular weight, pH, pH measurement, physical chemistry, priority journal, scanning electron microscopy, solid state, X ray diffraction, chemistry, drug stability, drug storage, medicinal chemistry, procedures, Acrylic Resins, Anti-Inflammatory Agents, Non-Steroidal, Calorimetry, Differential Scanning, Chemistry, Pharmaceutical, Crystallization, Drug Stability, Drug Storage, Freeze Drying, Hydrogen-Ion Concentration, Microscopy, Electron, Scanning, Molecular Weight, ortho-Aminobenzoates, Polymers, Spectroscopy, Fourier Transform Infrared, X-Ray Diffraction",

author = "M.A. Sheraz and S. Ahmed and I.U. Rehman",

year = "2015",

doi = "10.3109/10837450.2013.871027",

language = "English",

volume = "20",

pages = "352--360",

journal = "Pharmaceutical Development and Technology",

issn = "1083-7450",

publisher = "INFORMA HEALTHCARE",

number = "3",

}

RIS

TY - JOUR

T1 - Effect of pH, polymer concentration and molecular weight on the physical state properties of tolfenamic acid

AU - Sheraz, M.A.

AU - Ahmed, S.

AU - Rehman, I.U.

PY - 2015

Y1 - 2015

N2 - Tolfenamic acid (TA) has been transformed from crystalline to amorphous state through freeze-drying by using varying ratios of polyacrylic acid (PA) at various pH values. The characterization of the films has been carried out using X-ray diffraction, differential scanning calorimetry, Fourier transform infrared (FTIR) spectrometry and scanning electron microscopy. The results showed a gradual change in the solid state properties of TA and a complete transformation into its amorphous form in 1:8, 1:4, 1:2 and 1:1 ratios at pH 3, 4, 5 and 6, respectively. FTIR spectrometry reveals the formation of a yellow polymorphic form of TA. Polymer molecular weight has also been observed to affect the drug transformation and interaction as the low molecular weight PA (Mw ∼ 1800) was found to be most effective followed by its medium (Mv ∼ 450 000) and high molecular weight (Mv ∼ 3 000 000) forms. No signs of recrystallization in the TA-PA films were noted during the 12-week storage period. PA of low molecular weight has also been found more effective in inhibiting the recrystallization of the melt upon cooling thus proving a valuable polymer in producing stable amorphous solid dispersions of TA. © 2015 Informa Healthcare USA, Inc.

AB - Tolfenamic acid (TA) has been transformed from crystalline to amorphous state through freeze-drying by using varying ratios of polyacrylic acid (PA) at various pH values. The characterization of the films has been carried out using X-ray diffraction, differential scanning calorimetry, Fourier transform infrared (FTIR) spectrometry and scanning electron microscopy. The results showed a gradual change in the solid state properties of TA and a complete transformation into its amorphous form in 1:8, 1:4, 1:2 and 1:1 ratios at pH 3, 4, 5 and 6, respectively. FTIR spectrometry reveals the formation of a yellow polymorphic form of TA. Polymer molecular weight has also been observed to affect the drug transformation and interaction as the low molecular weight PA (Mw ∼ 1800) was found to be most effective followed by its medium (Mv ∼ 450 000) and high molecular weight (Mv ∼ 3 000 000) forms. No signs of recrystallization in the TA-PA films were noted during the 12-week storage period. PA of low molecular weight has also been found more effective in inhibiting the recrystallization of the melt upon cooling thus proving a valuable polymer in producing stable amorphous solid dispersions of TA. © 2015 Informa Healthcare USA, Inc.

KW - Amorphous

KW - Characterization

KW - Freeze-drying

KW - Polyacrylic acid

KW - Recrystallization

KW - polymer

KW - tolfenamic acid

KW - acrylic acid resin

KW - anthranilic acid derivative

KW - carbopol 940

KW - nonsteroid antiinflammatory agent

KW - Article

KW - crystallization

KW - differential scanning calorimetry

KW - drug solubility

KW - drug structure

KW - drug transformation

KW - freeze drying

KW - infrared spectroscopy

KW - molecular weight

KW - pH

KW - pH measurement

KW - physical chemistry

KW - priority journal

KW - scanning electron microscopy

KW - solid state

KW - X ray diffraction

KW - chemistry

KW - drug stability

KW - drug storage

KW - medicinal chemistry

KW - procedures

KW - Acrylic Resins

KW - Anti-Inflammatory Agents, Non-Steroidal

KW - Calorimetry, Differential Scanning

KW - Chemistry, Pharmaceutical

KW - Crystallization

KW - Drug Stability

KW - Drug Storage

KW - Freeze Drying

KW - Hydrogen-Ion Concentration

KW - Microscopy, Electron, Scanning

KW - Molecular Weight

KW - ortho-Aminobenzoates

KW - Polymers

KW - Spectroscopy, Fourier Transform Infrared

KW - X-Ray Diffraction

U2 - 10.3109/10837450.2013.871027

DO - 10.3109/10837450.2013.871027

M3 - Journal article

VL - 20

SP - 352

EP - 360

JO - Pharmaceutical Development and Technology

JF - Pharmaceutical Development and Technology

SN - 1083-7450

IS - 3

ER -

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