1
|
Xu X, Grohganz H, Rades T. Anti-plasticizing effect of water on prilocaine and lidocaine - the role of the hydrogen bonding pattern. Phys Chem Chem Phys 2024; 26:14149-14159. [PMID: 38712380 DOI: 10.1039/d4cp00995a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/08/2024]
Abstract
It is generally accepted that water, as an effective plasticizer, decreases the glass transition temperatures (Tgs) of amorphous drugs, potentially resulting in physical instabilities. However, recent studies suggest that water can also increase the Tgs of the amorphous forms of the drugs prilocaine (PRL) and lidocaine (LID), thus acting as an anti-plasticizer. To further understand the nature of the anti-plasticizing effect of water, interactions with different solvents and the resulting structural features of PRL and LID were investigated by Fourier transform infrared spectroscopy (FTIR) and quantum chemical simulations. Heavy water (deuterium oxides) was chosen as a solvent, as the deuterium and hydrogen atoms are electronically identical. It was found that substituting hydrogen with deuterium showed a minimal impact on the anti-plasticization of water on PRL. Ethanol and ethylene glycol were chosen as solvents to compare the hydrogen bonding patterns occurring between the hydroxyl groups of the solvents and PRL and LID. Comparison of the various Tgs showed a weaker anti-plasticizing potential of these two solvents on PRL and LID. The frequency shifts of the amide CO groups of PRL and LID due to the interactions with water, heavy water, ethanol, and ethylene glycol as observed in the FTIR spectra showed a correlation with the binding energies calculated by quantum chemical simulations. Overall, this study showed that the combination of weak hydrogen bonding and strong electrostatic contributions in hydrated PRL and LID could play an important role in inducing the anti-plasticizing effect of water on those drugs.
Collapse
Affiliation(s)
- Xiaoyue Xu
- Department of Pharmacy, University of Copenhagen, Universitetsparken 2, 2100 Copenhagen, Denmark.
| | - Holger Grohganz
- Department of Pharmacy, University of Copenhagen, Universitetsparken 2, 2100 Copenhagen, Denmark.
| | - Thomas Rades
- Department of Pharmacy, University of Copenhagen, Universitetsparken 2, 2100 Copenhagen, Denmark.
| |
Collapse
|
2
|
Xu X, Rades T, Grohganz H. Molecular interactions of hydrated co-amorphous systems of prilocaine and lidocaine. Int J Pharm 2024; 651:123807. [PMID: 38220121 DOI: 10.1016/j.ijpharm.2024.123807] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2023] [Revised: 01/10/2024] [Accepted: 01/11/2024] [Indexed: 01/16/2024]
Abstract
It is generally accepted that water as a plasticizer can decrease the glass transition temperatures (Tgs) of amorphous drugs and drug excipient systems. However, previous studies suggest that water, as an anti-plasticizer, can increase the Tgs of co-amorphous systems of prilocaine (PRL) and lidocaine (LID). In order to investigate the intermolecular interactions between water and co-amorphous PRL-LID systems, Fourier transform infrared spectroscopy (FTIR) and principal component analysis (PCA) were conducted. Water was found to bind with the carbonyl groups of PRL and LID molecularly evenly in the hydrated co-amorphous PRL-LID systems. Quantum chemical simulations visually confirmed the interactions between water and co-amorphous PRL-LID systems. Furthermore, the physical stability of hydrated co-amorphous PRL-LID systems was improved due to the anti-plasticizing effect of water, compared with the anhydrous samples. The preference of water to interact with the carbonyl groups of PRL and LID as binding sites could be associated with the anti-plasticizing effect of water on the co-amorphous PRL-LID systems.
Collapse
Affiliation(s)
- Xiaoyue Xu
- Department of Pharmacy, University of Copenhagen, Universitetsparken 2, 2100 Copenhagen, Denmark
| | - Thomas Rades
- Department of Pharmacy, University of Copenhagen, Universitetsparken 2, 2100 Copenhagen, Denmark.
| | - Holger Grohganz
- Department of Pharmacy, University of Copenhagen, Universitetsparken 2, 2100 Copenhagen, Denmark
| |
Collapse
|
3
|
Tsakiri M, Zivko C, Demetzos C, Mahairaki V. Lipid-based nanoparticles and RNA as innovative neuro-therapeutics. Front Pharmacol 2022; 13:900610. [PMID: 36016560 PMCID: PMC9395673 DOI: 10.3389/fphar.2022.900610] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2022] [Accepted: 07/13/2022] [Indexed: 11/13/2022] Open
Abstract
RNA-delivery is a promising tool to develop therapies for difficult to treat diseases such as neurological disorders, by silencing pathological genes or expressing therapeutic proteins. However, in many cases RNA delivery requires a vesicle that could effectively protect the molecule from bio-degradation, bypass barriers i.e., the blood brain barrier, transfer it to a targeted tissue and efficiently release the RNA inside the cells. Many vesicles such as viral vectors, and polymeric nanoparticles have been mentioned in literature. In this review, we focus in the discussion of lipid-based advanced RNA-delivery platforms. Liposomes and lipoplexes, solid lipid nanoparticles and lipid nanoparticles are the main categories of lipidic platforms for RNA-delivery to the central nervous systems (CNS). A variety of surface particles' modifications and routes of administration have been studied to target CNS providing encouraging results in vivo. It is concluded that lipid-based nanoplatforms will play a key role in the development of RNA neuro-therapies.
Collapse
Affiliation(s)
- Maria Tsakiri
- Section of Pharmaceutical Technology, Department of Pharmacy, School of Health Sciences, National and Kapodistrian University of Athens, Athens, Greece
| | - Cristina Zivko
- Section of Pharmaceutical Technology, Department of Pharmacy, School of Health Sciences, National and Kapodistrian University of Athens, Athens, Greece
- Department of Genetic Medicine, Johns Hopkins School of Medicine, Baltimore, MD, United States
| | - Costas Demetzos
- Section of Pharmaceutical Technology, Department of Pharmacy, School of Health Sciences, National and Kapodistrian University of Athens, Athens, Greece
| | - Vasiliki Mahairaki
- Section of Pharmaceutical Technology, Department of Pharmacy, School of Health Sciences, National and Kapodistrian University of Athens, Athens, Greece
- Department of Genetic Medicine, Johns Hopkins School of Medicine, Baltimore, MD, United States
| |
Collapse
|
4
|
Abstract
Water is generally regarded as a universal plasticizer of amorphous drugs or amorphous drug-containing systems. A decrease in glass-transition temperature (Tg) is considered the general result of this plasticizing effect. A recent study exhibits that water can increase the Tg of amorphous prilocaine (PRL) and thus shows an anti-plasticizing effect. The structurally similar drug lidocaine (LID) might show similar interactions with water, and thus an anti-plasticizing effect of water is hypothesized to also occur in amorphous LID. However, the influence of water on the Tg of LID cannot be determined directly due to the very low stability of LID in the amorphous form. It is possible to predict the Tg of LID from a co-amorphous system of PRL-LID using the Gordon-Taylor equation. Interactions were observed between PRL and LID based on the deviations between the experimental Tgs and the Tgs calculated by the conventional use of the Gordon-Taylor equation. A modified use of the Gordon-Taylor equation was applied using the optimal co-amorphous system as a separate component and the excess drug as the other component. The predicted Tg of fully hydrated LID could thus be determined and was found to be increased by 0.9 ± 0.7 K compared with the Tg of water-free amorphous LID. It could be shown that water exhibited a small anti-plasticizing effect on LID.
Collapse
Affiliation(s)
- Xiaoyue Xu
- Department of Pharmacy, University of Copenhagen, Universitetsparken 2, 2100 Copenhagen, Denmark
| | - Holger Grohganz
- Department of Pharmacy, University of Copenhagen, Universitetsparken 2, 2100 Copenhagen, Denmark
| | - Thomas Rades
- Department of Pharmacy, University of Copenhagen, Universitetsparken 2, 2100 Copenhagen, Denmark
| |
Collapse
|
5
|
Zotova J, Twamley B, Tajber L. Impact of the Dicarboxylic Acid Chain Length on Intermolecular Interactions with Lidocaine. Mol Pharm 2022; 19:2980-2991. [PMID: 35850530 PMCID: PMC9346613 DOI: 10.1021/acs.molpharmaceut.2c00381] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Acid-base multicomponent systems have become a popular choice as a strategy to fine-tune the physicochemical properties of active pharmaceutical ingredients. Current prediction tools based on the principles of anticrystal engineering cannot always accurately predict the nature of intermolecular interactions within a multicomponent system. Even small changes in the physicochemical parameters of parent components can result in unexpected outcomes, and many salt, cocrystal, and ionic liquid forms are still being discovered empirically. In this work, we aimed to establish structural consistency in a series of mixtures comprising lidocaine (LID) with decanedioic, undecanedioic, dodecanedioic, and tridecanedioic acids and to explore how length and flexibility of the acid carbon backbone affect the molecular recognition, crystallization, and thermal behavior of the expected binary systems. We found that neat grinding of LID with dicarboxylic acids results in the formation of eutectic phases. The observed eutectic melting points deviated from the ideal eutectic temperatures predicted by the Schroeder van Laar model because of hydrogen bonding between the reacting components within the mixtures. Furthermore, thermal and infrared analysis provided evidence for the possible formation of new phases stemming from partial ionization of the counterions. Besides, the structure of a previously undetermined form I of the tridecanedioic acid was solved by single crystal X-ray diffraction.
Collapse
Affiliation(s)
- Julija Zotova
- School of Pharmacy and Pharmaceutical Sciences, Trinity College Dublin, College Green, Dublin 2, Ireland
| | - Brendan Twamley
- School of Chemistry, Trinity College Dublin, College Green, Dublin 2, Ireland
| | - Lidia Tajber
- School of Pharmacy and Pharmaceutical Sciences, Trinity College Dublin, College Green, Dublin 2, Ireland
| |
Collapse
|
6
|
Röwekamp L, Moch K, Gainaru C, Böhmer R. Predicting Dielectric and Shear-Rheology Properties of Glass-Forming Pharmaceutical Liquids from Each Other: Applications and Limitations. Mol Pharm 2022; 19:1586-1597. [PMID: 35405077 DOI: 10.1021/acs.molpharmaceut.2c00077] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Acetaminophen, nicotine, and lidocaine hydrochloride were investigated in their deeply supercooled liquid states using oscillatory shear rheology. The mechanical spectra of these drugs are presented in modulus, compliance, as well as fluidity formats. Their frequency profiles can be described via models adapted from the field of charge transport. Inspired by the success of this approach, the Barton-Nakajima-Namikawa relation, best known from the same field, was also tested. When adapted to rheology, this approach interrelates static and dynamic characteristics of viscous flow and was found to work excellently. The temperature dependence of the characteristic shear frequencies was checked against the shoving model, which relates them to the temperature-dependent instantaneous shear modulus and acceptable agreement was found. Combined with shear mechanical literature data on ibuprofen and indomethacin, a modified version of the phenomenological model by Gemant, DiMarzio, and Bishop (GDB) was employed to successfully predict the shape and amplitude of the dielectric spectra for all studied liquids, except for lidocaine hydrochloride. For the latter, the modified GDB model is suggested to aid in mapping out the reorientational part of the dielectric response, while the experimental results are strongly superimposed by ionic conduction phenomena. The reverse transformation, the calculation of rheological spectra based on dielectric ones, is also successfully demonstrated. For the example of acetyl salicylic acid, it is shown how dielectric spectra can be used to even predict rheological ones. The limits of the central parameter governing these mutual transformations, the electroviscoelastic material constant, and indications for its correlation with the dielectric relaxation strength are discussed. For pharmaceuticals characterized by a strong dynamical decoupling of the electrical from the mechanical degrees of freedom, the modified GDB model is not expected to be applicable.
Collapse
Affiliation(s)
- Lara Röwekamp
- Fakultät Physik, Technische Universität Dortmund, 44221 Dortmund, Germany
| | - Kevin Moch
- Fakultät Physik, Technische Universität Dortmund, 44221 Dortmund, Germany
| | - Catalin Gainaru
- Fakultät Physik, Technische Universität Dortmund, 44221 Dortmund, Germany.,Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
| | - Roland Böhmer
- Fakultät Physik, Technische Universität Dortmund, 44221 Dortmund, Germany
| |
Collapse
|
7
|
Huang C, Chen X, Wei C, Wang H, Gao H. Deep Eutectic Solvents as Active Pharmaceutical Ingredient Delivery Systems in the Treatment of Metabolic Related Diseases. Front Pharmacol 2022; 12:794939. [PMID: 35002726 PMCID: PMC8740069 DOI: 10.3389/fphar.2021.794939] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2021] [Accepted: 11/23/2021] [Indexed: 11/13/2022] Open
Abstract
Metabolic related diseases such as cancer, diabetes mellitus and atherosclerosis are major challenges for human health and safety worldwide due to their associations with high morbidity and mortality. It is of great significance to develop the effective active pharmaceutical ingredient (API) delivery systems for treatment of metabolic diseases. With their unique merits like easy preparation, high adjustability, low toxicity, low cost, satisfactory stability and biodegradation, deep eutectic solvents (DESs) are unarguably green and sustainable API delivery systems that have been developed to improve drug solubility and treat metabolic related diseases including cancer, diabetes mellitus and atherosclerosis. Many reports about DESs as API delivery systems in the therapy of cancer, diabetes mellitus and atherosclerosis exist but no systematic overview of these results is available, which motivated the current work.
Collapse
Affiliation(s)
- Cixin Huang
- State Key Laboratory Cultivation Base, Shandong Provincial Key Laboratory of Ophthalmology, Eye Institute of Shandong First Medical University, Qingdao, China.,Eye Hospital of Shandong First Medical University (Shandong Eye Hospital), Jinan, China.,Medical College, Qingdao University, Qingdao, China
| | - Xiunian Chen
- State Key Laboratory Cultivation Base, Shandong Provincial Key Laboratory of Ophthalmology, Eye Institute of Shandong First Medical University, Qingdao, China.,Eye Hospital of Shandong First Medical University (Shandong Eye Hospital), Jinan, China.,Medical College, Qingdao University, Qingdao, China
| | - Chao Wei
- State Key Laboratory Cultivation Base, Shandong Provincial Key Laboratory of Ophthalmology, Eye Institute of Shandong First Medical University, Qingdao, China.,School of Ophthalmology, Shandong First Medical University, Jinan, China
| | - Hongwei Wang
- State Key Laboratory Cultivation Base, Shandong Provincial Key Laboratory of Ophthalmology, Eye Institute of Shandong First Medical University, Qingdao, China.,School of Ophthalmology, Shandong First Medical University, Jinan, China
| | - Hua Gao
- State Key Laboratory Cultivation Base, Shandong Provincial Key Laboratory of Ophthalmology, Eye Institute of Shandong First Medical University, Qingdao, China.,Eye Hospital of Shandong First Medical University (Shandong Eye Hospital), Jinan, China.,School of Ophthalmology, Shandong First Medical University, Jinan, China
| |
Collapse
|
8
|
Zotova J, Wojnarowska Z, Twamley B, Tajber L. Formation of stoichiometric and non-stoichiometric ionic liquid and cocrystal multicomponent phases of lidocaine with azelaic acid by changing counterion ratios. J Mol Liq 2021. [DOI: 10.1016/j.molliq.2021.117737] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
|
9
|
Formation of low melting point binary systems comprising ketoprofen and an amide local anaesthetic. Int J Pharm 2021; 607:120969. [PMID: 34358543 DOI: 10.1016/j.ijpharm.2021.120969] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2021] [Revised: 07/22/2021] [Accepted: 07/30/2021] [Indexed: 11/20/2022]
Abstract
Liquid forms of active pharmaceutical ingredients, ionic liquids (ILs) and deep eutectic mixtures (DEMs), offer several potential benefits in respect to advancing pharmaceutical formulations. The aim of this study was to develop and characterise ILs/DEMs composed of two active molecules: ketoprofen (KET), as the acidic component, and a local anaesthetics (LA), lidocaine (LID), mepivacaine (MEP) or bupivacaine (BUP), which constituted the basic component. A mechanosynthetic approach was successfully applied to obtain LA-KET low melting systems. Composition/temperature phase diagrams were determined by differential scanning calorimetry. The amide LA-KET mixtures showed a eutectic behaviour during heating and formed viscous liquids upon quench cooling. Considering the quench cooled LA-KET mixtures, LA crystallisation was observed only in the LA-rich mixtures. LID, MEP and BUP formed disordered complexes with KET at an approximate 1:2 stoichiometry. Infrared spectroscopy studies revealed that the mixtures were composed mainly of hydrogen bonded acid and base molecules, but small amounts of carboxylate anions were detected. The formation of LA-KET complex not only suppressed the high crystallisation tendency of the LA molecules in the dry state, but also eliminated the crystallisation of KET and LA molecules induced by moisture, as revealed by dynamic vapour sorption studies.
Collapse
|
10
|
Bialek K, Wojnarowska Z, Twamley B, Tajber L. Characterisation and fundamental insight into the formation of new solid state, multicomponent systems of propranolol. Int J Pharm 2021; 602:120605. [PMID: 33862135 DOI: 10.1016/j.ijpharm.2021.120605] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2021] [Revised: 04/07/2021] [Accepted: 04/09/2021] [Indexed: 11/27/2022]
Abstract
The physiochemical properties of acidic or basic active pharmaceutical ingredients (APIs) can be optimised by forming salts with different counterions. The aim of this work was to synthesise a novel salt of propranolol (PRO) using sebacic acid (SEBA) as the counterion and to gain mechanistic understanding of not only the salt formation, but also its eutectic phase formation with SEBA. Thermal analysis showed a solid-state reaction occurring between PRO and SEBA leading to the formation of dipropranolol sebacate (DPS) melting at app. 170 °C and the eutectic composed of DPS and SEBA melting at app. 103 °C, comprising 0.33 mol fraction of PRO as determined by the Tammann plot. X-ray diffraction and Fourier-transform infrared spectroscopy (FTIR) confirmed the identity of the new multicomponent phases of PRO. DPS can be conveniently obtained by heat-induced crystallisation, grinding and conventional solvent crystallisation. Detailed analysis by FTIR revealed H-bond interactions between DPS and SEBA at the inter-phase in the eutectic. Bravais, Friedel, Donnay and Harker crystal morphology coupled with full interaction maps analysis allowed to understand further the nature of interactions which led to formation of the eutectic phase. This work contributes to furthering research on multicomponent pharmaceutical systems to harness their full potential.
Collapse
Affiliation(s)
- Klaudia Bialek
- School of Pharmacy and Pharmaceutical Sciences, Trinity College Dublin, College Green, Dublin 2, Ireland
| | - Zaneta Wojnarowska
- School of Pharmacy and Pharmaceutical Sciences, Trinity College Dublin, College Green, Dublin 2, Ireland; Institute of Physics, University of Silesia, SMCEBI, 75 Pulku Piechoty 1A, 41-500 Chorzow, Poland
| | - Brendan Twamley
- School of Chemistry, Trinity College Dublin, College Green, Dublin 2, Ireland
| | - Lidia Tajber
- School of Pharmacy and Pharmaceutical Sciences, Trinity College Dublin, College Green, Dublin 2, Ireland.
| |
Collapse
|
11
|
Bin Sintang MD, Danthine S, Khalenkow D, Tavernier I, Tzompa Sosa DA, Julmohammad NB, Van de Walle D, Rimaux T, Skirtach A, Dewettinck K. Modulating the crystallization of phytosterols with monoglycerides in the binary mixture systems: mixing behavior and eutectic formation. Chem Phys Lipids 2020; 230:104912. [DOI: 10.1016/j.chemphyslip.2020.104912] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2019] [Revised: 04/03/2020] [Accepted: 04/11/2020] [Indexed: 02/06/2023]
|
12
|
Umerska A, Bialek K, Zotova J, Skotnicki M, Tajber L. Anticrystal Engineering of Ketoprofen and Ester Local Anesthetics: Ionic Liquids or Deep Eutectic Mixtures? Pharmaceutics 2020; 12:pharmaceutics12040368. [PMID: 32316479 PMCID: PMC7237996 DOI: 10.3390/pharmaceutics12040368] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2020] [Revised: 04/13/2020] [Accepted: 04/14/2020] [Indexed: 12/23/2022] Open
Abstract
Ionic liquids (ILs) and deep eutectic mixtures (DEMs) are potential solutions to the problems of low solubility, polymorphism, and low bioavailability of drugs. The aim of this work was to develop and investigate ketoprofen (KET)-based ILs/DEMs containing an ester local anesthetic (LA): benzocaine (BEN), procaine (PRO) and tetracaine (TET) as the second component. ILs/DEMs were prepared via a mechanosynthetic process that involved the mixing of KET with an LA in a range of molar ratios and applying a thermal treatment. After heating above the melting point and quench cooling, the formation of supercooled liquids with Tgs that were dependent on the composition was observed for all KET-LA mixtures with exception of that containing 95 mol% of BEN. The KET-LA mixtures containing either ≥ 60 mol% BEN or 95 mol% of TET showed crystallization to BEN and TET, respectively, during either cooling or second heating. KET decreased the crystallization tendency of BEN and TET and increased their glass-forming ability. The KET-PRO systems showed good glass-forming ability and did not crystallize either during the cooling or during the second heating cycle irrespective of the composition. Infrared spectroscopy and molecular modeling indicated that KET and LAs formed DEMs, but in the KET-PRO systems small quantities of carboxylate anions were present.
Collapse
Affiliation(s)
- Anita Umerska
- School of Pharmacy and Pharmaceutical Sciences, Trinity College Dublin, College Green, Dublin 2, Ireland; (A.U.); (K.B.); (J.Z.); (M.S.)
| | - Klaudia Bialek
- School of Pharmacy and Pharmaceutical Sciences, Trinity College Dublin, College Green, Dublin 2, Ireland; (A.U.); (K.B.); (J.Z.); (M.S.)
| | - Julija Zotova
- School of Pharmacy and Pharmaceutical Sciences, Trinity College Dublin, College Green, Dublin 2, Ireland; (A.U.); (K.B.); (J.Z.); (M.S.)
| | - Marcin Skotnicki
- School of Pharmacy and Pharmaceutical Sciences, Trinity College Dublin, College Green, Dublin 2, Ireland; (A.U.); (K.B.); (J.Z.); (M.S.)
- Department of Pharmaceutical Technology, Poznań University of Medical Sciences, 60-780 Poznań, Poland
| | - Lidia Tajber
- School of Pharmacy and Pharmaceutical Sciences, Trinity College Dublin, College Green, Dublin 2, Ireland; (A.U.); (K.B.); (J.Z.); (M.S.)
- Correspondence: ; Tel.: +353-1-896-2787
| |
Collapse
|
13
|
Wojnarowska Z, Zotowa J, Knapik-Kowalczuk J, Tajber L, Paluch M. Effect of electrostatic interactions on the relaxation dynamics of pharmaceutical eutectics. Eur J Pharm Sci 2019; 134:93-101. [PMID: 30986473 DOI: 10.1016/j.ejps.2019.04.014] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2018] [Revised: 03/10/2019] [Accepted: 04/10/2019] [Indexed: 10/27/2022]
Abstract
In this paper, we investigate the temperature-dependent relaxation dynamics in the glassy and supercooled liquid state of dipolar and ionic eutectic mixtures made of two anesthetic agents (lidocaine and prilocaine) and their hydrochloride salts, respectively. In addition to eutectic phases containing 1:1 and 4:1 mol/mol of LD/PRL and LD-HCl/PRL-HCl, respectively, the relaxation properties of non-eutectic compositions and parent compounds are also studied. We found that electrostatic long-range forces determine strongly the dielectric and mechanical response of eutectic material. As a result of Coulomb interactions between ion pairs, an additional β-relaxation mode was found in the dielectric spectra of glassy LD-HCl/PRL-HCl mixtures. On the other hand, the studies of relaxation dynamics of ionic and non-ionic mixtures at T > Tg revealed a continuous decrease of both fragility mP and the length scale of dynamic heterogeneity NαB(Tg), with simultaneous growth of Tg, when the electrostatics forces appear. At the same time, we found the charge transport being decoupled from structural dynamics in all studied ionic binary mixtures that is due to the fast proton hopping. However, the efficiency of proton transport is dropping down with an increase of Tg.
Collapse
Affiliation(s)
- Z Wojnarowska
- Institute of Physics, University of Silesia, SMCEBI, 75 Pulku Piechoty 1A, 41-500 Chorzow, Poland; School of Pharmacy and Pharmaceutical Sciences, Trinity College Dublin, College Green, Dublin 2, Ireland.
| | - J Zotowa
- School of Pharmacy and Pharmaceutical Sciences, Trinity College Dublin, College Green, Dublin 2, Ireland
| | - J Knapik-Kowalczuk
- Institute of Physics, University of Silesia, SMCEBI, 75 Pulku Piechoty 1A, 41-500 Chorzow, Poland
| | - L Tajber
- School of Pharmacy and Pharmaceutical Sciences, Trinity College Dublin, College Green, Dublin 2, Ireland
| | - M Paluch
- Institute of Physics, University of Silesia, SMCEBI, 75 Pulku Piechoty 1A, 41-500 Chorzow, Poland
| |
Collapse
|