Characterization and Comparison of Lidocaine-Tetracaine and Lidocaine-Camphor Eutectic Mixtures Based on Their Crystallization and Hydrogen-Bonding Abilities

Urvi Gala, Monica C. Chuong, Ravi Varanasi, Harsh Chauhan

Research output: Contribution to journalArticle

3 Citations (Scopus)

Abstract

Eutectic mixtures formed between active pharmaceutical ingredients and/or excipients provide vast scope for pharmaceutical applications. This study aimed at the exploration of the crystallization abilities of two eutectic mixtures (EM) i.e., lidocaine-tetracaine and lidocaine-camphor (1:1 w/w). Thermogravimetric analysis (TGA) for degradation behavior whereas modulated temperature differential scanning calorimetry (MTDSC) set in first heating, cooling, and second heating cycles, was used to qualitatively analyze the complex exothermic and endothermic thermal transitions. Raman microspectroscopy characterized vibrational information specific to chemical bonds. Prepared EMs were left at room temperature for 24 h to visually examine their crystallization potentials. The degradation of lidocaine, tetracaine, camphor, lidocaine-tetracaine EM, and lidocaine-camphor EM began at 196.56, 163.82, 76.86, 146.01, and 42.72°C, respectively, which indicated that eutectic mixtures are less thermostable compared to their individual components. The MTDSC showed crystallization peaks for lidocaine, tetracaine, and camphor at 31.86, 29.36, and 174.02°C, respectively (n = 3). When studying the eutectic mixture, no crystallization peak was observed in the lidocaine-tetracaine EM, but a lidocaine-camphor EM crystallization peak was present at 18.81°C. Crystallization occurred in lidocaine-camphor EM after being kept at room temperature for 24 h, but not in lidocaine-tetracaine EM. Certain peak shifts were observed in Raman spectra which indicated possible interactions of eutectic mixture components, when a eutectic mixture was formed. We found that if the components forming a eutectic mixture have crystallization peaks close to each other and have sufficient hydrogen-bonding capability, then their eutectic mixture is least likely to crystallize out (as seen in lidocaine-tetracaine EM) or vice versa (lidocaine-camphor EM).

Original languageEnglish
Pages (from-to)528-536
Number of pages9
JournalAAPS PharmSciTech
Volume16
Issue number3
DOIs
StatePublished - Nov 6 2015

Fingerprint

Tetracaine
Camphor
lidocaine
hydrogen bonding
camphor
Hydrogen Bonding
Lidocaine
crystallization
Crystallization
Temperature
Differential Scanning Calorimetry
Heating
differential scanning calorimetry
heat
ambient temperature
Excipients
chemical bonding
thermogravimetry
drugs
Pharmaceutical Preparations

All Science Journal Classification (ASJC) codes

  • Pharmaceutical Science

Cite this

Characterization and Comparison of Lidocaine-Tetracaine and Lidocaine-Camphor Eutectic Mixtures Based on Their Crystallization and Hydrogen-Bonding Abilities. / Gala, Urvi; Chuong, Monica C.; Varanasi, Ravi; Chauhan, Harsh.

In: AAPS PharmSciTech, Vol. 16, No. 3, 06.11.2015, p. 528-536.

Research output: Contribution to journalArticle

@article{acf6f63fa2af40b08de20a3e6ecc1023,
title = "Characterization and Comparison of Lidocaine-Tetracaine and Lidocaine-Camphor Eutectic Mixtures Based on Their Crystallization and Hydrogen-Bonding Abilities",
abstract = "Eutectic mixtures formed between active pharmaceutical ingredients and/or excipients provide vast scope for pharmaceutical applications. This study aimed at the exploration of the crystallization abilities of two eutectic mixtures (EM) i.e., lidocaine-tetracaine and lidocaine-camphor (1:1 w/w). Thermogravimetric analysis (TGA) for degradation behavior whereas modulated temperature differential scanning calorimetry (MTDSC) set in first heating, cooling, and second heating cycles, was used to qualitatively analyze the complex exothermic and endothermic thermal transitions. Raman microspectroscopy characterized vibrational information specific to chemical bonds. Prepared EMs were left at room temperature for 24 h to visually examine their crystallization potentials. The degradation of lidocaine, tetracaine, camphor, lidocaine-tetracaine EM, and lidocaine-camphor EM began at 196.56, 163.82, 76.86, 146.01, and 42.72°C, respectively, which indicated that eutectic mixtures are less thermostable compared to their individual components. The MTDSC showed crystallization peaks for lidocaine, tetracaine, and camphor at 31.86, 29.36, and 174.02°C, respectively (n = 3). When studying the eutectic mixture, no crystallization peak was observed in the lidocaine-tetracaine EM, but a lidocaine-camphor EM crystallization peak was present at 18.81°C. Crystallization occurred in lidocaine-camphor EM after being kept at room temperature for 24 h, but not in lidocaine-tetracaine EM. Certain peak shifts were observed in Raman spectra which indicated possible interactions of eutectic mixture components, when a eutectic mixture was formed. We found that if the components forming a eutectic mixture have crystallization peaks close to each other and have sufficient hydrogen-bonding capability, then their eutectic mixture is least likely to crystallize out (as seen in lidocaine-tetracaine EM) or vice versa (lidocaine-camphor EM).",
author = "Urvi Gala and Chuong, {Monica C.} and Ravi Varanasi and Harsh Chauhan",
year = "2015",
month = "11",
day = "6",
doi = "10.1208/s12249-014-0242-4",
language = "English",
volume = "16",
pages = "528--536",
journal = "AAPS PharmSciTech",
issn = "1530-9932",
publisher = "American Association of Pharmaceutical Scientists",
number = "3",

}

TY - JOUR

T1 - Characterization and Comparison of Lidocaine-Tetracaine and Lidocaine-Camphor Eutectic Mixtures Based on Their Crystallization and Hydrogen-Bonding Abilities

AU - Gala, Urvi

AU - Chuong, Monica C.

AU - Varanasi, Ravi

AU - Chauhan, Harsh

PY - 2015/11/6

Y1 - 2015/11/6

N2 - Eutectic mixtures formed between active pharmaceutical ingredients and/or excipients provide vast scope for pharmaceutical applications. This study aimed at the exploration of the crystallization abilities of two eutectic mixtures (EM) i.e., lidocaine-tetracaine and lidocaine-camphor (1:1 w/w). Thermogravimetric analysis (TGA) for degradation behavior whereas modulated temperature differential scanning calorimetry (MTDSC) set in first heating, cooling, and second heating cycles, was used to qualitatively analyze the complex exothermic and endothermic thermal transitions. Raman microspectroscopy characterized vibrational information specific to chemical bonds. Prepared EMs were left at room temperature for 24 h to visually examine their crystallization potentials. The degradation of lidocaine, tetracaine, camphor, lidocaine-tetracaine EM, and lidocaine-camphor EM began at 196.56, 163.82, 76.86, 146.01, and 42.72°C, respectively, which indicated that eutectic mixtures are less thermostable compared to their individual components. The MTDSC showed crystallization peaks for lidocaine, tetracaine, and camphor at 31.86, 29.36, and 174.02°C, respectively (n = 3). When studying the eutectic mixture, no crystallization peak was observed in the lidocaine-tetracaine EM, but a lidocaine-camphor EM crystallization peak was present at 18.81°C. Crystallization occurred in lidocaine-camphor EM after being kept at room temperature for 24 h, but not in lidocaine-tetracaine EM. Certain peak shifts were observed in Raman spectra which indicated possible interactions of eutectic mixture components, when a eutectic mixture was formed. We found that if the components forming a eutectic mixture have crystallization peaks close to each other and have sufficient hydrogen-bonding capability, then their eutectic mixture is least likely to crystallize out (as seen in lidocaine-tetracaine EM) or vice versa (lidocaine-camphor EM).

AB - Eutectic mixtures formed between active pharmaceutical ingredients and/or excipients provide vast scope for pharmaceutical applications. This study aimed at the exploration of the crystallization abilities of two eutectic mixtures (EM) i.e., lidocaine-tetracaine and lidocaine-camphor (1:1 w/w). Thermogravimetric analysis (TGA) for degradation behavior whereas modulated temperature differential scanning calorimetry (MTDSC) set in first heating, cooling, and second heating cycles, was used to qualitatively analyze the complex exothermic and endothermic thermal transitions. Raman microspectroscopy characterized vibrational information specific to chemical bonds. Prepared EMs were left at room temperature for 24 h to visually examine their crystallization potentials. The degradation of lidocaine, tetracaine, camphor, lidocaine-tetracaine EM, and lidocaine-camphor EM began at 196.56, 163.82, 76.86, 146.01, and 42.72°C, respectively, which indicated that eutectic mixtures are less thermostable compared to their individual components. The MTDSC showed crystallization peaks for lidocaine, tetracaine, and camphor at 31.86, 29.36, and 174.02°C, respectively (n = 3). When studying the eutectic mixture, no crystallization peak was observed in the lidocaine-tetracaine EM, but a lidocaine-camphor EM crystallization peak was present at 18.81°C. Crystallization occurred in lidocaine-camphor EM after being kept at room temperature for 24 h, but not in lidocaine-tetracaine EM. Certain peak shifts were observed in Raman spectra which indicated possible interactions of eutectic mixture components, when a eutectic mixture was formed. We found that if the components forming a eutectic mixture have crystallization peaks close to each other and have sufficient hydrogen-bonding capability, then their eutectic mixture is least likely to crystallize out (as seen in lidocaine-tetracaine EM) or vice versa (lidocaine-camphor EM).

UR - http://www.scopus.com/inward/record.url?scp=84929959251&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84929959251&partnerID=8YFLogxK

U2 - 10.1208/s12249-014-0242-4

DO - 10.1208/s12249-014-0242-4

M3 - Article

VL - 16

SP - 528

EP - 536

JO - AAPS PharmSciTech

JF - AAPS PharmSciTech

SN - 1530-9932

IS - 3

ER -