X-ray powder diffractometric method for quantitation of crystalline drug in microparticulate systems. I. Microspheres

Alekha K. Dash, A. Khin-Khin, R. Suryanarayanan

Research output: Contribution to journalArticle

25 Citations (Scopus)

Abstract

Ethylcellulose microspheres containing tolnaftate (I) were prepared by the emulsion-solvent evaporation technique. An X-ray powder diffractometric method was developed to quantify the content of crystalline I in these microspheres. X-ray lines of I with d-spacings of 5.5 and 4.2 Å were chosen for the quantitative analyses. Physical mixtures containing various weight fractions of I and blank (empty) microspheres were prepared and lithium fluoride (20% w/w) was added as the internal standard. The 5.5 and 4.3 Å lines of I and the 2.3 Å line of lithium fluoride were used for the quantitative analysis. A plot of the intensity ratio (intensity of the 5.5 Å line of I/intensity of 2.3 Å line of lithium fluoride) as a function of the weight percent of I in the mixture, resulted in a straight line. The crystalline content of I in the tolnaftate-loaded microspheres was determined using this standard curve. A second independent determination of the content of I was possible from the intensities of the 4.3 Å line. The enthalpy of fusion of I, determined by differential scanning calorimetry (DSC), was also used as a measure of the crystalline content of I in the microspheres. The X-ray and DSC methods measure the content of crystalline I in the microspheres at room temperature (∼25°C) and at the melting point of I (111°C), respectively. The total content of I in the microspheres was determined by HPLC. The DSC and X-ray results indicated that a substantial fraction of the incorporated I was dissolved in the ethylcellulose matrix.

Original languageEnglish
Pages (from-to)983-990
Number of pages8
JournalJournal of Pharmaceutical Sciences
Volume91
Issue number4
DOIs
StatePublished - 2002

Fingerprint

Microspheres
Powders
X ray powder diffraction
X-Rays
Crystalline materials
X rays
Pharmaceutical Preparations
Differential Scanning Calorimetry
Tolnaftate
Differential scanning calorimetry
Weights and Measures
Emulsions
Freezing
Melting point
Enthalpy
Evaporation
Fusion reactions
High Pressure Liquid Chromatography
Temperature
Chemical analysis

All Science Journal Classification (ASJC) codes

  • Drug Discovery
  • Organic Chemistry
  • Chemistry(all)
  • Molecular Medicine
  • Pharmacology
  • Pharmaceutical Science

Cite this

X-ray powder diffractometric method for quantitation of crystalline drug in microparticulate systems. I. Microspheres. / Dash, Alekha K.; Khin-Khin, A.; Suryanarayanan, R.

In: Journal of Pharmaceutical Sciences, Vol. 91, No. 4, 2002, p. 983-990.

Research output: Contribution to journalArticle

@article{833c16bce3384be4871e04ec9d5426ce,
title = "X-ray powder diffractometric method for quantitation of crystalline drug in microparticulate systems. I. Microspheres",
abstract = "Ethylcellulose microspheres containing tolnaftate (I) were prepared by the emulsion-solvent evaporation technique. An X-ray powder diffractometric method was developed to quantify the content of crystalline I in these microspheres. X-ray lines of I with d-spacings of 5.5 and 4.2 {\AA} were chosen for the quantitative analyses. Physical mixtures containing various weight fractions of I and blank (empty) microspheres were prepared and lithium fluoride (20{\%} w/w) was added as the internal standard. The 5.5 and 4.3 {\AA} lines of I and the 2.3 {\AA} line of lithium fluoride were used for the quantitative analysis. A plot of the intensity ratio (intensity of the 5.5 {\AA} line of I/intensity of 2.3 {\AA} line of lithium fluoride) as a function of the weight percent of I in the mixture, resulted in a straight line. The crystalline content of I in the tolnaftate-loaded microspheres was determined using this standard curve. A second independent determination of the content of I was possible from the intensities of the 4.3 {\AA} line. The enthalpy of fusion of I, determined by differential scanning calorimetry (DSC), was also used as a measure of the crystalline content of I in the microspheres. The X-ray and DSC methods measure the content of crystalline I in the microspheres at room temperature (∼25°C) and at the melting point of I (111°C), respectively. The total content of I in the microspheres was determined by HPLC. The DSC and X-ray results indicated that a substantial fraction of the incorporated I was dissolved in the ethylcellulose matrix.",
author = "Dash, {Alekha K.} and A. Khin-Khin and R. Suryanarayanan",
year = "2002",
doi = "10.1002/jps.10090",
language = "English",
volume = "91",
pages = "983--990",
journal = "Journal of Pharmaceutical Sciences",
issn = "0022-3549",
publisher = "John Wiley and Sons Inc.",
number = "4",

}

TY - JOUR

T1 - X-ray powder diffractometric method for quantitation of crystalline drug in microparticulate systems. I. Microspheres

AU - Dash, Alekha K.

AU - Khin-Khin, A.

AU - Suryanarayanan, R.

PY - 2002

Y1 - 2002

N2 - Ethylcellulose microspheres containing tolnaftate (I) were prepared by the emulsion-solvent evaporation technique. An X-ray powder diffractometric method was developed to quantify the content of crystalline I in these microspheres. X-ray lines of I with d-spacings of 5.5 and 4.2 Å were chosen for the quantitative analyses. Physical mixtures containing various weight fractions of I and blank (empty) microspheres were prepared and lithium fluoride (20% w/w) was added as the internal standard. The 5.5 and 4.3 Å lines of I and the 2.3 Å line of lithium fluoride were used for the quantitative analysis. A plot of the intensity ratio (intensity of the 5.5 Å line of I/intensity of 2.3 Å line of lithium fluoride) as a function of the weight percent of I in the mixture, resulted in a straight line. The crystalline content of I in the tolnaftate-loaded microspheres was determined using this standard curve. A second independent determination of the content of I was possible from the intensities of the 4.3 Å line. The enthalpy of fusion of I, determined by differential scanning calorimetry (DSC), was also used as a measure of the crystalline content of I in the microspheres. The X-ray and DSC methods measure the content of crystalline I in the microspheres at room temperature (∼25°C) and at the melting point of I (111°C), respectively. The total content of I in the microspheres was determined by HPLC. The DSC and X-ray results indicated that a substantial fraction of the incorporated I was dissolved in the ethylcellulose matrix.

AB - Ethylcellulose microspheres containing tolnaftate (I) were prepared by the emulsion-solvent evaporation technique. An X-ray powder diffractometric method was developed to quantify the content of crystalline I in these microspheres. X-ray lines of I with d-spacings of 5.5 and 4.2 Å were chosen for the quantitative analyses. Physical mixtures containing various weight fractions of I and blank (empty) microspheres were prepared and lithium fluoride (20% w/w) was added as the internal standard. The 5.5 and 4.3 Å lines of I and the 2.3 Å line of lithium fluoride were used for the quantitative analysis. A plot of the intensity ratio (intensity of the 5.5 Å line of I/intensity of 2.3 Å line of lithium fluoride) as a function of the weight percent of I in the mixture, resulted in a straight line. The crystalline content of I in the tolnaftate-loaded microspheres was determined using this standard curve. A second independent determination of the content of I was possible from the intensities of the 4.3 Å line. The enthalpy of fusion of I, determined by differential scanning calorimetry (DSC), was also used as a measure of the crystalline content of I in the microspheres. The X-ray and DSC methods measure the content of crystalline I in the microspheres at room temperature (∼25°C) and at the melting point of I (111°C), respectively. The total content of I in the microspheres was determined by HPLC. The DSC and X-ray results indicated that a substantial fraction of the incorporated I was dissolved in the ethylcellulose matrix.

UR - http://www.scopus.com/inward/record.url?scp=0036279478&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0036279478&partnerID=8YFLogxK

U2 - 10.1002/jps.10090

DO - 10.1002/jps.10090

M3 - Article

VL - 91

SP - 983

EP - 990

JO - Journal of Pharmaceutical Sciences

JF - Journal of Pharmaceutical Sciences

SN - 0022-3549

IS - 4

ER -