Solid-State Properties of Tobramycin

Alekha K. Dash, Raj Suryanarayanan

Research output: Contribution to journalArticle

24 Citations (Scopus)

Abstract

Tobramycin I obtained from two different sources was subjected to powder X-ray diffractometry, thermal analyses, and Karl Fischer titrimetry. It was concluded to be tobramycin monohydrate (C18H37N5O9 · H2O). When heated in the differential scanning calorimeter (DSC), the dehydration of I resulted in the formation of metastable anhydrous tobramycin, which melted at 164°C. This was followed by the crystallization of the stable anhydrous tobramycin, which then melted at 217°C. The polymorphic transition was concluded to be monotropic and the calculated free energy difference between the metastable and the stable forms, at 25°C, was 348 cal · mol−1. Both the heating rate in the DSC and the sample size had a significant influence on the enthalpy values of most of the thermal events. These observations were attributed to the presence of trace amounts of moisture in the sample. No detectable decomposition of I occurred when it was heated up to 224°C.

Original languageEnglish
Pages (from-to)1159-1165
Number of pages7
JournalPharmaceutical Research
Volume8
Issue number9
DOIs
StatePublished - 1991

Fingerprint

Tobramycin
Calorimeters
Titrimetry
Hot Temperature
Scanning
Crystallization
Heating rate
Dehydration
Sample Size
Powders
Heating
X ray diffraction analysis
Free energy
Enthalpy
Moisture
X-Rays
Decomposition

All Science Journal Classification (ASJC) codes

  • Biotechnology
  • Molecular Medicine
  • Organic Chemistry
  • Pharmacology (medical)
  • Pharmaceutical Science
  • Pharmacology
  • Chemistry(all)

Cite this

Solid-State Properties of Tobramycin. / Dash, Alekha K.; Suryanarayanan, Raj.

In: Pharmaceutical Research, Vol. 8, No. 9, 1991, p. 1159-1165.

Research output: Contribution to journalArticle

Dash, Alekha K. ; Suryanarayanan, Raj. / Solid-State Properties of Tobramycin. In: Pharmaceutical Research. 1991 ; Vol. 8, No. 9. pp. 1159-1165.
@article{b6d7fcf5294d40de97b2985cd3732f06,
title = "Solid-State Properties of Tobramycin",
abstract = "Tobramycin I obtained from two different sources was subjected to powder X-ray diffractometry, thermal analyses, and Karl Fischer titrimetry. It was concluded to be tobramycin monohydrate (C18H37N5O9 · H2O). When heated in the differential scanning calorimeter (DSC), the dehydration of I resulted in the formation of metastable anhydrous tobramycin, which melted at 164°C. This was followed by the crystallization of the stable anhydrous tobramycin, which then melted at 217°C. The polymorphic transition was concluded to be monotropic and the calculated free energy difference between the metastable and the stable forms, at 25°C, was 348 cal · mol−1. Both the heating rate in the DSC and the sample size had a significant influence on the enthalpy values of most of the thermal events. These observations were attributed to the presence of trace amounts of moisture in the sample. No detectable decomposition of I occurred when it was heated up to 224°C.",
author = "Dash, {Alekha K.} and Raj Suryanarayanan",
year = "1991",
doi = "10.1023/A:1015858503031",
language = "English",
volume = "8",
pages = "1159--1165",
journal = "Pharmaceutical Research",
issn = "0724-8741",
publisher = "Springer New York",
number = "9",

}

TY - JOUR

T1 - Solid-State Properties of Tobramycin

AU - Dash, Alekha K.

AU - Suryanarayanan, Raj

PY - 1991

Y1 - 1991

N2 - Tobramycin I obtained from two different sources was subjected to powder X-ray diffractometry, thermal analyses, and Karl Fischer titrimetry. It was concluded to be tobramycin monohydrate (C18H37N5O9 · H2O). When heated in the differential scanning calorimeter (DSC), the dehydration of I resulted in the formation of metastable anhydrous tobramycin, which melted at 164°C. This was followed by the crystallization of the stable anhydrous tobramycin, which then melted at 217°C. The polymorphic transition was concluded to be monotropic and the calculated free energy difference between the metastable and the stable forms, at 25°C, was 348 cal · mol−1. Both the heating rate in the DSC and the sample size had a significant influence on the enthalpy values of most of the thermal events. These observations were attributed to the presence of trace amounts of moisture in the sample. No detectable decomposition of I occurred when it was heated up to 224°C.

AB - Tobramycin I obtained from two different sources was subjected to powder X-ray diffractometry, thermal analyses, and Karl Fischer titrimetry. It was concluded to be tobramycin monohydrate (C18H37N5O9 · H2O). When heated in the differential scanning calorimeter (DSC), the dehydration of I resulted in the formation of metastable anhydrous tobramycin, which melted at 164°C. This was followed by the crystallization of the stable anhydrous tobramycin, which then melted at 217°C. The polymorphic transition was concluded to be monotropic and the calculated free energy difference between the metastable and the stable forms, at 25°C, was 348 cal · mol−1. Both the heating rate in the DSC and the sample size had a significant influence on the enthalpy values of most of the thermal events. These observations were attributed to the presence of trace amounts of moisture in the sample. No detectable decomposition of I occurred when it was heated up to 224°C.

UR - http://www.scopus.com/inward/record.url?scp=0025900603&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0025900603&partnerID=8YFLogxK

U2 - 10.1023/A:1015858503031

DO - 10.1023/A:1015858503031

M3 - Article

C2 - 1788162

AN - SCOPUS:0025900603

VL - 8

SP - 1159

EP - 1165

JO - Pharmaceutical Research

JF - Pharmaceutical Research

SN - 0724-8741

IS - 9

ER -