Tag Archives: cyclodextrins

Characterization of Inclusion Complexes between Miconazole and Different Cyclodextrin Derivatives

Hajnal Kelemen1, Gabriel Hancu1, Serban Andrei Gâz-Florea2, Eniko Nemes-Nagy3, Lajos Attila Papp1, Eleonora Mircia4

1. Department of Pharmaceutical Chemistry, Faculty of Pharmacy, University of Medicine and Pharmacy, Tîrgu Mureş, Romania
2. Department of Organic Chemistry, Faculty of Pharmacy, University of Medicine and Pharmacy, Tîrgu Mureş, Romania
3. Department of Biochemistry, Faculty of Pharmacy, University of Medicine and Pharmacy, Tîrgu Mureş, Romania
4. Department of Pharmaceutical Industry, Faculty of Pharmacy, University of Medicine and Pharmacy, Tîrgu Mureş, Romania

DOI: 10.2478/amma-2018-0012

Objective: Miconazole, an imidazole antifungal derivative, is a very hydrophobic compound, a major drawback in obtaining topical pharmaceutical formulations with optimal bioavailability. Cyclodextrins (CDs) may increase local drug delivery by enhancing the drug release and/or permeation. The aim of the study is the characterization of inclusion complexes between miconazole and different CD derivatives.
Methods: Several CD derivatives were tested in the experiments. The binary systems between miconazole and different CDs were prepared in 1:1 molar ratios by physical-mixture and kneading methods. Differential scanning calorimetry (DSC) and Fourier transformed-infrared spectroscopy (FT-IR) methods were used to characterize solid state interactions between miconazole and CDs in their binary systems.
Results: The FT-IR analysis suggests the formation of a new solid phase, indicating a molecular interaction between the components. The DSC analysis sustains the hypothesis of formation of partial inclusion complexes between miconazole nitrate and CD. Conclusion: The thermic behaviour of the complexes depends both on the preparation method and the composition of the products.

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Comparative Enantioseparation of Amlodipine by HPLC and Capillary Electrophoresis

Anca Gabriela Cârje, Alina Balint, Daniela-Lucia Muntean, Gabriel Hancu, Valentin Ion, Silvia Imre

University of Medicine and Pharmacy from Tirgu Mures, Romania

DOI: 10.2478/amma-2018-0001

Objective: The purpose of this study was to separate the enantiomers of amlodipine by High Performance Liquid Chromatography (HPLC) using ovomucoid (OVM) as chiral selector, respectively by Capillary Electrophoresis (CE) using cyclodextrines and to evaluate the analytical performance of the both proposed methods.
Material and methods: HPLC enantioseparation of amlodipine was performed on an HPLC Agilent Technologies 1100 series using as chiral stationary phase an Ultron ES OVM, 150×4.6 mm column with ovomucoid as chiral selector. The stereoselective CE analysis of amlodipine was achieved on Agilent Technologies 7100 CE using uncoated fused-silica capillaries 48 cm x 50 mm and different type of cyclodextrins as chiral selectors.
Results: A mobile phase consisting of 80% Na2HPO4 10 mM at a pH level of 5.0 and 20% ACN, isocratic elution at a flow of 1 ml/min turned to be the optimal experimental conditions for HPLC analysis (R=5.51; α=1.71) with retention times shorter than 10 minutes for the two isomers, tR (S-AML) = 4.63 (min); tR (R-AML) = 5.54 (min). The migration times for amlodipine enantiomers were tm (S-AML) = 8.15 (min) and tm (R-AML)= 8.45 (min) and the optimum CE conditions have proven to be a buffer solution containing 25 mM H3PO4 at pH 3.0 and 20 mM α-CD as chiral selector and a capillary temperature set at 15°C (R=1.51; α=1.03).
Conclusion: The analytical performances of the chromatographic method using OVM as chiral selector are superior to the electrophoretic analysis method but the CE method is more economical and may represent an alternative to the HPLC chromatographic separation.

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Improvements of Oxacillin Stability in a pH = 1.2 Acidic Environment

Rad I1, Croitoru MD2, Gyéresi Á2

1 Dimitrie Cantemir College, Tîrgu Mureș
2 University of Medicine and Pharmacy of Tîrgu Mureș, Faculty of Pharmacy

Introduction: Oxacillin sodium is a semisynthetic penicillin used in therapy against Staphylococcus species. It is orally administered as capsules. Because of the low stability of oxacillin in stomach acid, a low bioavailability is recorded during oral administration (30%).
The aim of this study was to improve, by using some auxiliary substances, the stability of oxacillin in acidic environment.
Methods: The improvement of oxacillin stability was measured by high performance liquid chromatography in the presence of β-cyclodextrin, 2-HP-β-cyclodextrin, magnesium glutamate and magnesium aspartate.
Results: Cyclodextrins significantly improved the stability of oxacillin in acidic environment. Glutamate and aspartate showed no effect on this regard. First order decomposition kinetics of oxacillin was modified by cyclodextrins.
Conclusions: Significant improvement of oxacillin stability and possible pharmacokinetics can be achieved by using cyclodextrins.

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Possibilities to Improve Benzylpenicillin and Phenoxymethylpenicillin Stability in Acidic Environment

Rad I1, Croitoru MD2, Gyéresi Á3

1 Dimitrie Cantemir College, Tîrgu Mureș, Romania
2 Department of Toxicology-Biopharmacy, Faculty of Pharmacy, University of Medicine and Pharmacy, Tîrgu Mureș, Romania
3 Department of Pharmaceutical Chemistry, Faculty of Pharmacy, University of Medicine and Pharmacy, Tîrgu Mureș, Romania

Background: Benzylpenicillin is water soluble natural penicillin used only by parenteral administration. Fast decomposition in acidic environment is the reason why benzylpenicillin can not be orally used. Phenoxymethylpenicillin is natural penicillin used in therapy by oral administration (filmed tablets, tablets, syrup, and suspension). It is relatively stable in acidic environment and has a bioavailability of about 50%.
Objective: The purpose of this study was to increase the stability of these penicillins in acidic environment (pH = 1.2) by using auxiliary substances: β-cyclodextrin, 2-hydroxypropil-β-cyclodextrin, magnesium glutamate and magnesium aspartate.
Methods: Improvements of stability were measured by high performance liquid chromatography in the absence and presence of the mentioned auxiliary substances.
Results: Cyclodextrins significantly improved the stability of the studied penicillins in acidic environment. Glutamate and aspartate showed no effect on this regard.
Conclusions: Significant improvement of benzylpenicillin and phenoxymethylpenicillin stability and possible pharmacokinetics can be achieved by using cyclodextrins.

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