Pickering emulsions are systems without surfactants, stabilized by solid particles. These emulsions are experiencing a renewed interest, on the one hand, because it is preferable to limit the use of synthetic surfacta...Pickering emulsions are systems without surfactants, stabilized by solid particles. These emulsions are experiencing a renewed interest, on the one hand, because it is preferable to limit the use of synthetic surfactants for toxicological and environmental reasons and, on the other hand, the need to make new formulations in order to control the drug release patterns by encapsulation or controlled release. Thus, we were interested in the formulation and evaluation of W/O Pickering emulsions stabilized by particles of magnesium oxide with paracetamol in the internal phase and griseofulvin in the external phase. The Bancroft rule served as a model for the formulation. The emulsification was carried out by progressively adding an aqueous phase dispersed in an oil-dispersing phase using a turbo rotor stator mixer. The stability of these emulsions was studied using several parameters (droplet size, pH, viscosity, conductivity ...) and the qualitative and quantitative analysis of the active ingredients by UV-visible spectrophotometry. The results obtained showed that the dye test and the conductivity measurement confirmed the W/O nature of these emulsions. Some parameters such as droplet size, pH and viscosity were strongly influenced by the amounts of magnesium oxide particles and the two active ingredients used. The qualitative and quantitative analysis of the active ingredients confirmed the presence of griseofulvin in the oil phase and paracetamol in the aqueous phase. Thus, we have succeeded in developing a stable W/O Pickering emulsion with magnesium oxide particles. In addition, we were able to incorporate paracetamol into the dispersed phase and griseofulvin into the dispersing phase of the emulsion.展开更多
Introduction:Griseofulvin is an antifungal drug belonging to Biopharmaceutical Classification System(BCS class II)having low solubility.Objectives:To formulate,evaluate and enhance the dissolution of poorly water solu...Introduction:Griseofulvin is an antifungal drug belonging to Biopharmaceutical Classification System(BCS class II)having low solubility.Objectives:To formulate,evaluate and enhance the dissolution of poorly water soluble drug Griseofulvin by using solid dispersion method.Methods:Six formulations were prepared by solid dispersion method using Polyethylene Glycol(PEG 6000)125 mg,0 mg,62.5 mg,100 mg,25 mg,150 mg and superdisintegrants Crospovidone 0 mg,125 mg,62.5 mg,100 mg,25 mg,150 mg in all batches respectively.Findings:Satisfactory results were obtained from evaluation of physical characteristics of Griseofulvin tablets including:carr’s compressibility index(17.5±0.19%to 11.76±0.67%),Hausner ratio(1.21±0.01 to 1.13±0.02)and post compression parameters including:thickness(5.16±0.02 mm to 4.57±0.19 mm),friability(0.024%to 0.322%),hardness(4±0.28 kg/cm^(2)to 5±0.57 kg/cm^(2)),disintegration time(14-870 seconds).Conclusions:F3 was best formulation among all formulated batches with in-vitro drug release 30.05%in 10 minutes,69.21%in 30 minutes and 97.11%in 45 minutes.This indicated that formulation F3 batch with PEG 6000 of 62.5 mg and crospovidone 62.5 mg showed increased dissolution.展开更多
Griseofulvin (GF) is an antifungal drug whose pharmaceutical activity can be improved by reducing particle size. In this study the rapid expansion of supercritical solution (RESS) was employed to micronize GF.Carbon d...Griseofulvin (GF) is an antifungal drug whose pharmaceutical activity can be improved by reducing particle size. In this study the rapid expansion of supercritical solution (RESS) was employed to micronize GF.Carbon dioxide with cosolvent acetone was chosen as a supercritical mixed solvent. The solubility of GF in super-critical CO2 with cosolvent acetone was measured using a dynamic apparatus at pressures between 12 and 32 MPa,temperatures at 313, 323 and 333 K and cosolvent concentration at 1.5, 3.0, 4.5 and 6.0% (by mole). The effect of pre-expansion pressure, extraction temperature, spraying distance, nozzle size and concentration of cosolvent on the precipitated particles was investigated. The results show that the mean particle size of griseofulvin precipitated by RESS was less than 1.2μm. An increase in pre-expansion pressure, extraction temperature, spraying distance and concentration of cosolvent resulted in a decrease in particle size under the operating condition studied. With the decrease of nozzle diameter the particle size reduces. The crystallinity and melting point of the original material and the processed particle by RESS were tested by X-ray diffraction (XRD) and differential scanning calorimetry (DSC).No evident modification in the crystal habit was found under the experimental conditions tested. The morphology of particles precipitated was analyzed bY scanning electron microscopy (SEM).展开更多
Marine microorganisms have long been recognized as potential sources for drug discovery.Griseofulvin was one of the first antifungal natural products and has been used as an antifungal agent for decades.In this study,...Marine microorganisms have long been recognized as potential sources for drug discovery.Griseofulvin was one of the first antifungal natural products and has been used as an antifungal agent for decades.In this study,12 new griseofulvin derivatives[(±)-1-2,(+)-3,(±)-4,10-12,and 14-15]and two new griseofulvin natural products(9 and 16)together with six known analogues[(-)-3,5-8,and 13]were isolated from the mangrove-derived fungus Nigrospora sp.QQYB1 treated with 0.3%NaCl or 2%NaBr in rice solid medium.Their 2D structures and absolute configurations were established by extensive spectroscopic analysis(1D and 2D NMR,HRESIMS),ECD spectra,computational calculation,DP4+analysis,and X-ray single-crystal diffraction.Compounds 1-4 represent the first griseofulvin enantiomers with four absolute configurations(2S,6'S;2R,6'R;2S,6'R;2R,6'S),and compounds 9-12 represent the first successful production of brominated griseofulvin derivatives from fungi via the addition of NaBr to the culture medium.In the antifungal assays,compounds 6 and 9 demonstrated significant inhibitory activities against the fungi Colletotrichum truncatum,Microsporum gypseum,and Trichophyton mentagrophyte with inhibition zones varying between 28 and 41 mm(10μg/disc).The structure-activity relationship(SAR)was analyzed,which showed that substituents at C-6,C-7,C-6'and the positions of the carbonyl and double bond of griseofulvin derivatives significantly affected the antifungal activity.展开更多
In an attempt to compare crystal structure determination from powder data and single-crystal data,crystal structure of griseofulvin(C 17 H 17 ClO 6) was tested by both powder and single-crystal X-ray diffraction.Latti...In an attempt to compare crystal structure determination from powder data and single-crystal data,crystal structure of griseofulvin(C 17 H 17 ClO 6) was tested by both powder and single-crystal X-ray diffraction.Lattice parameters of griseofulvin are α=90.0°,a=b=8.9757,c=19.9345,V=1605.99 3 from powder data coinciding with α=90.0°,a=b=8.9714,c=19.8848,V=1600.46 3 from single-crystal data.Main processes of structure elucidating of griseofulvin by the two approaches were analyzed.Powder X-ray diffraction was demonstrated to be a powerful auxiliary implement to single-crystal X-ray diffraction in structure characterization,and its application can be popularized in the field of structure research of small organic molecules.展开更多
文摘Pickering emulsions are systems without surfactants, stabilized by solid particles. These emulsions are experiencing a renewed interest, on the one hand, because it is preferable to limit the use of synthetic surfactants for toxicological and environmental reasons and, on the other hand, the need to make new formulations in order to control the drug release patterns by encapsulation or controlled release. Thus, we were interested in the formulation and evaluation of W/O Pickering emulsions stabilized by particles of magnesium oxide with paracetamol in the internal phase and griseofulvin in the external phase. The Bancroft rule served as a model for the formulation. The emulsification was carried out by progressively adding an aqueous phase dispersed in an oil-dispersing phase using a turbo rotor stator mixer. The stability of these emulsions was studied using several parameters (droplet size, pH, viscosity, conductivity ...) and the qualitative and quantitative analysis of the active ingredients by UV-visible spectrophotometry. The results obtained showed that the dye test and the conductivity measurement confirmed the W/O nature of these emulsions. Some parameters such as droplet size, pH and viscosity were strongly influenced by the amounts of magnesium oxide particles and the two active ingredients used. The qualitative and quantitative analysis of the active ingredients confirmed the presence of griseofulvin in the oil phase and paracetamol in the aqueous phase. Thus, we have succeeded in developing a stable W/O Pickering emulsion with magnesium oxide particles. In addition, we were able to incorporate paracetamol into the dispersed phase and griseofulvin into the dispersing phase of the emulsion.
基金This research received no specific grant from any funding agency in public,commercial,or not-for-profit sectors.
文摘Introduction:Griseofulvin is an antifungal drug belonging to Biopharmaceutical Classification System(BCS class II)having low solubility.Objectives:To formulate,evaluate and enhance the dissolution of poorly water soluble drug Griseofulvin by using solid dispersion method.Methods:Six formulations were prepared by solid dispersion method using Polyethylene Glycol(PEG 6000)125 mg,0 mg,62.5 mg,100 mg,25 mg,150 mg and superdisintegrants Crospovidone 0 mg,125 mg,62.5 mg,100 mg,25 mg,150 mg in all batches respectively.Findings:Satisfactory results were obtained from evaluation of physical characteristics of Griseofulvin tablets including:carr’s compressibility index(17.5±0.19%to 11.76±0.67%),Hausner ratio(1.21±0.01 to 1.13±0.02)and post compression parameters including:thickness(5.16±0.02 mm to 4.57±0.19 mm),friability(0.024%to 0.322%),hardness(4±0.28 kg/cm^(2)to 5±0.57 kg/cm^(2)),disintegration time(14-870 seconds).Conclusions:F3 was best formulation among all formulated batches with in-vitro drug release 30.05%in 10 minutes,69.21%in 30 minutes and 97.11%in 45 minutes.This indicated that formulation F3 batch with PEG 6000 of 62.5 mg and crospovidone 62.5 mg showed increased dissolution.
文摘Griseofulvin (GF) is an antifungal drug whose pharmaceutical activity can be improved by reducing particle size. In this study the rapid expansion of supercritical solution (RESS) was employed to micronize GF.Carbon dioxide with cosolvent acetone was chosen as a supercritical mixed solvent. The solubility of GF in super-critical CO2 with cosolvent acetone was measured using a dynamic apparatus at pressures between 12 and 32 MPa,temperatures at 313, 323 and 333 K and cosolvent concentration at 1.5, 3.0, 4.5 and 6.0% (by mole). The effect of pre-expansion pressure, extraction temperature, spraying distance, nozzle size and concentration of cosolvent on the precipitated particles was investigated. The results show that the mean particle size of griseofulvin precipitated by RESS was less than 1.2μm. An increase in pre-expansion pressure, extraction temperature, spraying distance and concentration of cosolvent resulted in a decrease in particle size under the operating condition studied. With the decrease of nozzle diameter the particle size reduces. The crystallinity and melting point of the original material and the processed particle by RESS were tested by X-ray diffraction (XRD) and differential scanning calorimetry (DSC).No evident modification in the crystal habit was found under the experimental conditions tested. The morphology of particles precipitated was analyzed bY scanning electron microscopy (SEM).
基金funded by the Guangdong Marine Economy Development Special Project(GDNRC[2022]35,GDNRC[2023]39)the National Natural Science Foundation of China(U20A2001,42276114).
文摘Marine microorganisms have long been recognized as potential sources for drug discovery.Griseofulvin was one of the first antifungal natural products and has been used as an antifungal agent for decades.In this study,12 new griseofulvin derivatives[(±)-1-2,(+)-3,(±)-4,10-12,and 14-15]and two new griseofulvin natural products(9 and 16)together with six known analogues[(-)-3,5-8,and 13]were isolated from the mangrove-derived fungus Nigrospora sp.QQYB1 treated with 0.3%NaCl or 2%NaBr in rice solid medium.Their 2D structures and absolute configurations were established by extensive spectroscopic analysis(1D and 2D NMR,HRESIMS),ECD spectra,computational calculation,DP4+analysis,and X-ray single-crystal diffraction.Compounds 1-4 represent the first griseofulvin enantiomers with four absolute configurations(2S,6'S;2R,6'R;2S,6'R;2R,6'S),and compounds 9-12 represent the first successful production of brominated griseofulvin derivatives from fungi via the addition of NaBr to the culture medium.In the antifungal assays,compounds 6 and 9 demonstrated significant inhibitory activities against the fungi Colletotrichum truncatum,Microsporum gypseum,and Trichophyton mentagrophyte with inhibition zones varying between 28 and 41 mm(10μg/disc).The structure-activity relationship(SAR)was analyzed,which showed that substituents at C-6,C-7,C-6'and the positions of the carbonyl and double bond of griseofulvin derivatives significantly affected the antifungal activity.
文摘In an attempt to compare crystal structure determination from powder data and single-crystal data,crystal structure of griseofulvin(C 17 H 17 ClO 6) was tested by both powder and single-crystal X-ray diffraction.Lattice parameters of griseofulvin are α=90.0°,a=b=8.9757,c=19.9345,V=1605.99 3 from powder data coinciding with α=90.0°,a=b=8.9714,c=19.8848,V=1600.46 3 from single-crystal data.Main processes of structure elucidating of griseofulvin by the two approaches were analyzed.Powder X-ray diffraction was demonstrated to be a powerful auxiliary implement to single-crystal X-ray diffraction in structure characterization,and its application can be popularized in the field of structure research of small organic molecules.
