The Nature of Hydrogen Bonded Ion-Pairs: The Reaction of Pyridine and Carboxylic Acids in Chloroform

Barrow, Gordon M.

doi:10.1021/ja01603a022

Cited by 181 publications

(64 citation statements)

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“…IPP is a frequently used cosmetic ingredient with low dielectric constant (ε r =3.18), which can contribute to the formation of ion pairs and simulate the highly lipophilic matrix such as pressuresensitive adhesives [23,29]. Different from the permeation experiments from patches, the permeation experiment from IPP ignores the influence of patch matrix; thus, the flux from IPP can represent the skin permeability of drugs to some extent.…”

Section: In Vitro Evaluationmentioning

confidence: 99%

Design and Evaluation of a Novel Felbinac Transdermal Patch: Combining Ion-Pair and Chemical Enhancer Strategy

Liu

Song

et al. 2015

AAPS PharmSciTech

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Abstract. The aim of this study was to design a novel felbinac (FEL) patch with significantly higher (P<0.05) skin permeation amount than the commercial product SELTOUCH® using ion-pair and chemical enhancer strategy, overcoming the disadvantage of the large application area of SELTOUCH®. Six complexes of FEL with organic amines diethylamine (DEA), triethylamine (TEA), N-(2′-hydroxyethanol)-piperdine (HEPP), monoethanolamine (MEtA), diethanolamine (DEtA), and triethanolamine (TEtA) were prepared by ion-pair interaction, and their formation were confirmed by differential scanning calorimetry (DSC), powder X-ray diffraction (pXRD), infared spectroscopy (IR), and proton nuclear magnetic resonance spectroscopy ( 1 H-NMR). Subsequently, the effect of ion-pair complexes and chemical enhancers were investigated through in vitro and in vivo experiments using rabbit abdominal skin. Results showed that FEL-TEA was the most potential candidate both in isopropyl palmitate (IPP) solution and transdermal patches. Combining use of 10% N-dodecylazepan-2-one (Azone), the optimized FEL-TEA patch achieved a flux of 18.29±2.59 μg/cm 2 /h, which was twice the amount of the product SELTOUCH® (J=9.18±1.26 μg/cm 2 /h). Similarly, the area under the concentration curve from time 0 to time t (AUC 0-t ) in FEL-TEA patch group (15.94±3.58 h.μg/mL) was also twice as that in SELTOUCH® group (7.31±1.16 h.μg/mL). Furthermore, the in vitro skin permeation results of FEL-TEA patch was found to have a good correlation with the in vivo absorption results in rabbit. These findings indicated that a combination of ion-pair and chemical enhancer strategy could be useful in developing a novel transdermal patch of FEL.KEY WORDS: chemical enhancer; felbinac-triethylamine (FEL-TEA); in vitro/in vivo correlation (IVIVC); ion-pair; transdermal patch.

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Section: In Vitro Evaluationmentioning

confidence: 99%

Design and Evaluation of a Novel Felbinac Transdermal Patch: Combining Ion-Pair and Chemical Enhancer Strategy

Liu

Song

et al. 2015

AAPS PharmSciTech

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“…3 for solutions 0.2 N in acid and 0.2 A' in pyridine. The additional peak at approximately 1635 cm-' for trichloroacetic acid solution is attributed to the formation of pyridinium ion (2,8).…”

Section: Resultsmentioning

confidence: 99%

“…Barrow (2) mentions that for trichloroacetic and Ultraviolet spectra of concentrated solutions trifluoroacetic acids and pyridine in chloroform, the (2-4 M ) pyridine in chloroform or methanol show no "wavelength shift is much less than would be ex-absorption above 280 nm but such solutions conPetted for a product with free symmetric carboxy-taining equilnolar amounts of trichloroacetic acid late group ... and that there is an absence a have extending to 400 nm. Dilution of the between carbonyl and carboxylate absorption."…”

Section: Resultsmentioning

confidence: 99%

“…Since Barrow's paper, in 1954 (I), many studies of carboxylic acid -ami~le equilibria have been reported in solvents such as carbon tetrachloride, chloroform (1,2), benzene (3), acetonitrile (4), and ether (5). In all cases there was evidence of 1 : 1, 2 : 1, and sometimes 3: 1 complex formation involving either h y d r~g e n bonding or proton transfer.…”

Section: Introductionmentioning

confidence: 99%

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Infrared studies of carboxylic acids and pyridine in chloroform and methanol

Dawa¹,

Gowland²

1978

Can. J. Chem.

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The reactions of acetic, chloroacetic, and trichloroacetic acids with varying relative concentrations of pyridine in chloroform have been reinvestigated using infrared spectroscopy. The same Systems have also been studied in methanol. Some different assignments of peaks have been made, and the anomalous infrared results previously observed for trichloroacetic acid in chloroform are explained in terms of charge transfer complex formation.

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“…From Figure 5, except HEPP, the stretching vibration of -OH group all changed after adding organic amines. From the above observation, a classical hydrogen bonded complex, a weak interaction, may have formed (Barrow, 1956;Hudson et al, 1972).…”

Section: Evidence Of Ion-pair Formationmentioning

confidence: 88%

The effect of ion-pair formation combined with penetration enhancers on the skin permeation of loxoprofen

et al. 2014

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Context: Loxoprofen (LOXO) is a non-steroidal anti-inflammatory drug. Repeated oral administrations induce gastrointestinal side effects. Patches are a promising alternative. Objective: The aim of this study was to investigate the effects of organic amines on the skin permeation of LOXO and finally design a patch with a comparable permeation profile and pharmacodynamic effects to the commercial LOXONA Õ plaster. Materials and methods: The effects of organic amines were assessed by flux values of LOXO from isopropyl myristate (IPM), using horizontal diffusion cell and rabbit skin. FTIR spectroscopy was used to confirm ion-pair formation. Anti-inflammatory and analgesic activity assessments were performed in the adjuvant arthritis rat model and acetic acid-induced writhing syndrome in mouse, separately. Results and discussion: Results showed that triethylamine (TEA) was the most potential candidate in IPM, with the highest flux of 499.75 ± 32.40 mg/cm 2 /h. In patch, the highest flux of 369.37 ± 34.32 mg/cm 2 /h was still obtained by LOXO-TEA. Combined with penetration enhancers, the cumulative amounts were further increased in presence of 5% IPM, which exhibited a flux of 840.04 ± 66.38 mg/cm 2 /h as two times of the commercial one. Ultimately, anti-inflammatory and analgesic activity assessment presented that a comparable pharmacodynamic activity with the commercial one could be obtained by the patch we designed. Additionally, we also found that LOXO patch applied topically exerted a systemic effect, and the effect was dose-dependent. Conclusion: It was feasible for LOXO patch design by combination of ion-pair technology and chemical enhancers.

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The Nature of Hydrogen Bonded Ion-Pairs: The Reaction of Pyridine and Carboxylic Acids in Chloroform

Cited by 181 publications

References 0 publications

Design and Evaluation of a Novel Felbinac Transdermal Patch: Combining Ion-Pair and Chemical Enhancer Strategy

Design and Evaluation of a Novel Felbinac Transdermal Patch: Combining Ion-Pair and Chemical Enhancer Strategy

Infrared studies of carboxylic acids and pyridine in chloroform and methanol

The effect of ion-pair formation combined with penetration enhancers on the skin permeation of loxoprofen

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