Characterization and Comparison of Lidocaine-Tetracaine and Lidocaine-Camphor Eutectic Mixtures Based on Their Crystallization and Hydrogen-Bonding Abilities
Journal Title: AAPS PharmSciTech - Year 2015, Vol 16, Issue 3
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).
Authors and Affiliations
Urvi Gala, Monica C. Chuong, Ravi Varanasi, Harsh Chauhan
Keywords
Related Articles
- EP ID EP682231
- DOI 10.1208/s12249-014-0242-4
- Views 57
- Downloads 0
Hydrogels Composed of Cyclodextrin Inclusion Complexes with PLGA-PEG-PLGA Triblock Copolymers as Drug Delivery Systems
Although conventional pharmaceuticals have many drug dosage forms on the market, the development of new therapeutic molecules and the low efficacy of instant release formulations for the treatment of some chronic disease...
Retraction Note: Meloxicam Taste-Masked Oral Disintegrating Tablet with Dissolution Enhanced by Ion Exchange Resins and Cyclodextrin
The online version of the original article can be found at 10.1208/s12249-013-0001-y.
Targeting Therapeutics Across the Blood Brain Barrier (BBB), Prerequisite Towards Thrombolytic Therapy for Cerebrovascular Disorders—an Overview and Advancements
Cerebral tissues possess highly selective and dynamic protection known as blood brain barrier (BBB) that regulates brain homeostasis and provides protection against invading pathogens and various chemicals including drug...
Nonionic Surfactant Vesicles Composed of Novel Spermine-Derivative Cationic Lipids as an Effective Gene Carrier In Vitro
In the present study, nonionic surfactant vesicles (niosomes) formulated with Span 20, cholesterol, and novel synthesized spermine-based cationic lipids with four hydrocarbon tails in a molar ratio of 2.5:2.5:1 were inve...
Novel Self-assembly Endows Human Serum Albumin Nanoparticles with an Enhanced Antitumor Efficacy
The online version of this article (doi:10.1208/s12249-013-0041-3) contains supplementary material, which is available to authorized users.