Nanocrystals,a carrier-free colloidal delivery system in nano-sized range,is an interesting approach for poorly soluble drugs.Nanocrystals provide special features including enhancement of saturation solubility,dissol...Nanocrystals,a carrier-free colloidal delivery system in nano-sized range,is an interesting approach for poorly soluble drugs.Nanocrystals provide special features including enhancement of saturation solubility,dissolution velocity and adhesiveness to surface/cell membranes.Several strategies are applied for nanocrystals production including precipitation,milling,high pressure homogenization and combination methods such as Nano-Edge^(TM),SmartCrystal and Precipitation-lyophilization-homogenization(PLH)technology.For oral administration,many publications reported useful advantages of nanocrystals to improve in vivo performances i.e.pharmacokinetics,pharmacodynamics,safety and targeted delivery which were discussed in this review.Additionally,transformation of nanocrystals to final formulations and future trends of nanocrystals were also described.展开更多
We applied a combination of inorganic mesoporous silica material,frequently used as drug carriers,and a natural organic polymer alginate(ALG),to establish a sustained drug delivery system for the poorly water-soluble ...We applied a combination of inorganic mesoporous silica material,frequently used as drug carriers,and a natural organic polymer alginate(ALG),to establish a sustained drug delivery system for the poorly water-soluble drug Indomethacin(IND).Mesoporous silica nanospheres(MSNs)were synthesized using an organic template method and then functionalized with aminopropyl groups through postsynthesis.After drug loading into the pores of aninopropyl functionalized MSNs(AP-MSNs),IND loaded AP-MSNs(IND-AP-MSNs)were encapsulated by ALG through the ionic interaction.The effects of surface chemical groups and ALG layer on IND release were systematically studied using scanning electron microscopy(SEM),transmission electron microscopy(TEM),nitrogen adsorption,zetapotential analysis and TGA analysis.The surface structure and surface charge changes of the ALG encapsulated AP-MSNs(ALG-AP-MSNs)were also investigated.The results showed that sustained release of IND from the designed drug delivery system was mainly due to the blockage effect from the coated ALG.We believe that this combination will help designing oral sustained drug delivery systems for poorly water-soluble drugs.展开更多
BACKGROUND Pancreatic cancer is a major cause of cancer-related death,with a 5-year overall survival rate being below 5%.The main causes of poor prognosis in pancreatic cancer include easy metastasis,high recurrence r...BACKGROUND Pancreatic cancer is a major cause of cancer-related death,with a 5-year overall survival rate being below 5%.The main causes of poor prognosis in pancreatic cancer include easy metastasis,high recurrence rate,and robust drug resistance.Gemcitabine is a first-line drug for patients with unresectable pancreatic cancer.However,due to drug resistance,the clinical effect is not satisfactory.ADAM28 is reported as a tumor promoter in some cancers,but its role in pancreatic cancer and gemcitabine chemoresistance in pancreatic cancer has not been elucidated.AIM To identify if ADAM28 can act as an important target to reverse the gemcitabine drug resistance in pancreatic cancer.METHODS RNA-sequence analysis was applied to explore the potential targets involved in the gemcitabine of pancreatic cancer.SW1990 pancreatic cancer cells were treated with an increased dose of gemcitabine,and the mRNA levels of ADAM28 were evaluated by RT-PCR.The protein and mRNA levels of ADAM28 were confirmed in the gemcitabine resistant and parallel SW1990 cells.The ADAM28 expression was also assessed in TCGA and GEO databases,and the results were confirmed in the collected tumor and adjacent normal tissues.The overall survival(OS)rate and relapse-free survival(RFS)rate of pancreatic cancer patients with high ADAM28 level and low ADAM28 level in TCGA were evaluated with Kaplan-Meier Plotter.Furthermore,the OS rate was calculated in pancreatic cancer patients with high tumor mutation burden(TMB)and low TMB.CCK-8 assay was used to examine the effect of ADAM28 on the viability of SW1990 cells.The ADAM28 and its co-expressed genes were analyzed in the cBioPortal for cancer genomics and subjected to GSEA pathway analysis.The correlations of ADAM28 with GSTP1,ABCC1,GSTM4,and BCL2 were analyzed based on TCGA data on pancreatic cancer.RESULTS RNA-sequence analysis identified that ADAM28 was overexpressed in gemcitabine-resistant cells,and gemcitabine treatment could induce the expression of ADAM28.The mRNA and protein levels of ADAM28 were elevated in gemcitabine-resistant SW1990 cells compared with parallel cells.Also,the expression of ADAM28 was upregulated in pancreatic tumor tissues against normal pancreatic tissues.Notably,ADAM28 was highly expressed in the classical type than in the basal tumor type.Furthermore,the high expression of ADAM28 was associated with low OS and RFS rates.Interestingly,the high levels of ADAM28 was associated with a significantly lower OS rate in the high TMB patients,but not in the low TMB patients.Moreover,overexpression of ADAM28 could reduce the cell viability inhibition by gemcitabine,and knockdown of ADAM28 could enhance the proliferation inhibition by gemcitabine.The GSEA analysis showed that ADAM28 was related to the regulation of drug metabolism,and ADAM28 was significantly positively correlated with GSTP1,ABCC1,GSTM4,and BCL2.CONCLUSION This study demonstrates that ADAM28 is overexpressed in pancreatic cancer,and closely involved in the regulation of gemcitabine resistance.Overexpression of ADAM28 is a novel prognostic biomarker in pancreatic cancer.展开更多
To enhance the dissolution of poorly soluble mefenamic acid,self-emulsifying formulation(SEF),composing of oil,surfactant and co-surfactant,was formulated.Among the oils and surfactants studied,Imwitor■ 742,Tween■ 6...To enhance the dissolution of poorly soluble mefenamic acid,self-emulsifying formulation(SEF),composing of oil,surfactant and co-surfactant,was formulated.Among the oils and surfactants studied,Imwitor■ 742,Tween■ 60,Cremophore■ EL and Transcutol■ HP were selected as they showed maximal solubility to mefenamic acid.The ternary phase diagram was constructed to find optimal concentration that provided the highest drug loading.The droplet size after dispersion and drug dissolution of selected formulations were investigated.The results showed that the formulation containing Imwitor■ 742,Tween■ 60 and Transcutol■ HP(10:30:60)can encapsulate high amount of mefenamic acid.The dissolution study demonstrated that,in the medium containing surfactant,nearly 100% of mefenamic acid were dissolved from SEF within 5 min while 80% of drugs were dissolved from the commercial product in 45 min.In phosphate buffer(without surfactant),80% of drug were dissolved from the developed SEF within 5 min while only about 13% of drug were dissolved in 45 min,from the commercial product.The results suggested that the SEF can enhance the dissolution of poorly soluble drug and has a potential to enhance drug absorption and improve bioavailability of drug.展开更多
Nanoparticles are considered to be a powerful approach for the delivery of poorly watersoluble drugs. One of the main challenges is developing an appropriate method for preparation of drug nanoparticles. As a simple, ...Nanoparticles are considered to be a powerful approach for the delivery of poorly watersoluble drugs. One of the main challenges is developing an appropriate method for preparation of drug nanoparticles. As a simple, rapid and scalable method, the flash nanoprecipitation(FNP) has been widely used to fabricate these drug nanoparticles, including pure drug nanocrystals, polymeric micelles,polymeric nanoparticles, solid lipid nanoparticles, and polyelectrolyte complexes. This review introduces the application of FNP to produce poorly water-soluble drug nanoparticles by controllable mixing devices, such as confined impinging jets mixer(CIJM), multi-inlet vortex mixer(MIVM) and many other microfluidic mixer systems. The formation mechanisms and processes of drug nanoparticles by FNP are described in detail. Then, the controlling of supersaturation level and mixing rate during the FNP process to tailor the ultrafine drug nanoparticles as well as the influence of drugs, solvent, anti-solvent, stabilizers and temperature on the fabrication are discussed. The ultrafine and uniform nanoparticles of poorly watersoluble drug nanoparticles prepared by CIJM, MIVM and microfluidic mixer systems are reviewed briefly. We believe that the application of microfluidic mixing devices in laboratory with continuous process control and good reproducibility will be benefit for industrial formulation scale-up.展开更多
Pharmaceutical particle technology is employed to improve poor aqueous solubility of drug compounds that limits in vivo bioavailability owing to their low dissolution rate in the gastrointestinal fluids following oral...Pharmaceutical particle technology is employed to improve poor aqueous solubility of drug compounds that limits in vivo bioavailability owing to their low dissolution rate in the gastrointestinal fluids following oral administration.The particle technology involves several approaches from the conventional size reduction processes to the newer,novel particle technologies that modify the solubility properties of the drugs and produce solid,powdered form of the drugs that are readily soluble in water and can be easily formulated into various dosage forms.This review highlights the solid particle technologies available for improving solubility,dissolution and bioavailability of drugs with poor aqueous solubility.展开更多
Dr. Wei Wu is a professor at the Department of Pharmaceutics, School of Pharmacy, Fudan University, Shanghai, China. His research interest is in the field of oral drug delivery systems and in vivo fate of drug nanocar...Dr. Wei Wu is a professor at the Department of Pharmaceutics, School of Pharmacy, Fudan University, Shanghai, China. His research interest is in the field of oral drug delivery systems and in vivo fate of drug nanocarriers. He and coworkers invented novel water-quenching ACQ fluorescent dyes to probe the in vivo fate of versatile nanoparticles administered via different routes.展开更多
Oral dosage forms including tablets and capsules are themost commonly used drug products. For some poorly water-soluble and poorly permeable drugs injectable dosage formscan be used to circumvent the challenges of poo...Oral dosage forms including tablets and capsules are themost commonly used drug products. For some poorly water-soluble and poorly permeable drugs injectable dosage formscan be used to circumvent the challenges of poor bioavailabil-ity.展开更多
The solid dispersion has become an established solubilization technology for poorly water soluble drugs.Since a solid dispersion is basically a drug-polymer two-component system,the drug-polymer interaction is the det...The solid dispersion has become an established solubilization technology for poorly water soluble drugs.Since a solid dispersion is basically a drug-polymer two-component system,the drug-polymer interaction is the determining factor in its design and performance.In this review,we summarize our current understanding of solid dispersions both in the solid state and in dissolution,emphasizing the fundamental aspects of this important technology.展开更多
In this study,using mesoporous silica for the solubility enhancement of poorly watersoluble drug was investigated.Although the incorporating drug into mesoporous silica is generally performed through the solvent meth...In this study,using mesoporous silica for the solubility enhancement of poorly watersoluble drug was investigated.Although the incorporating drug into mesoporous silica is generally performed through the solvent method,the new melting method was proposed in the present study.Fenofibrate,a poorly water-soluble drug,was incorporated into mesoporous silica by solvent method and melting method.The obtained samples were observed by SEM and their physicochemical properties were evaluated by PXRD and DSC measurement.The dissolution and supersaturated property were also investigated.The results from SEM,PXRD and DSC measurement showed that drug could be loaded into pore via the melting method as well as by the solvent method.The drug loaded quantity depended on the pore volume.Drug up to 33%could be incorporated into mesoporous silica and existed in amorphous state.When drug was overloaded or difficulty in incorporation into pore was found,recrystallization of drug occurred at the outer surface of mesoporous silica.From the dissolution test,samples prepared by solvent method and melting method gave the supersaturated drug concentration which sample from melting method showed superior dissolution to the one from solvent method.From this study,drug was efficiently incorporated into mesoporous silica by the melting method which is a simple and solvent-free process,and the aqueous solubility enhancement of poorly watersoluble drug was achieved.展开更多
Kaempferia parviflora, a plant in the family Zingiberaceae, has been used in Thai traditional medicines for treating hypertension and promoting longevity with good health and wellbeing. However, its limited aqueous so...Kaempferia parviflora, a plant in the family Zingiberaceae, has been used in Thai traditional medicines for treating hypertension and promoting longevity with good health and wellbeing. However, its limited aqueous solubility and low dissolution restrict its bioavailability.The aim of the study was therefore to improve the dissolution rate of K. parviflora extracted with dichloromethane(KPD) by solid dispersions. Different water-soluble polymers were applied to improve dissolution of KPD. The solid dispersions in different ratios were prepared by solvent evaporation method. Only hydroxypropyl methylcellulose(HPMC) and polyvinyl alcohol-polyethylene glycol grafted copolymer(PVA-co-PEG) could be used to produce homogeneous, powdered solid dispersions. Physical characterization by scanning electron microscopy, hot stage microscopy, differential scanning calorimetry and powder X-ray diffractometry, in comparison with corresponding physical mixtures, showed the changes in solid state during the formation of solid dispersions. Dissolution of a selected marker,5,7,4′-trimethoxyflavone(TMF), from KPD/HPMC and KPD/PVA-co-PEG solid dispersions was significantly improved, compared with pure KPD. The dissolution enhancement by solid dispersion was influenced by both type and content of polymers. The stability of KPD/HPMC and KPD/PVA-co-PEG solid dispersions was also good after 6-month storage in both longterm and accelerated conditions. These results identified that the KPD/HPMC and KPD/PVAco-PEG solid dispersions were an effective new approach for pharmaceutical application of K. parviflora.展开更多
The objective of the present study was to alter the crystal habit of itraconazole(ITZ)by cooling and anti-solvent crystallization and characterize its properties.ITZ was recrystallized in different solvents and the ef...The objective of the present study was to alter the crystal habit of itraconazole(ITZ)by cooling and anti-solvent crystallization and characterize its properties.ITZ was recrystallized in different solvents and the effects of each solvent on morphology of crystals,dissolution behavior and solid state of recrystallized drug particles were investigated.The results revealed that ITZ crystals recrystallized by cooling and anti-solvent crystallization showed the different crystal habits from the untreated ITZ.Using cooling crystallization tended to provide needle-shaped crystals while the crystals obtained from anti-solvent crystallization showed more flaky,plate shape.This indicated the importance of preparation method on nucleation and crystal growth.No change in drug polymorphism was observed,according to determination of thermal property and crystalline state by differential scanning calorimetry and powder X-ray diffractometry,respectively.The recrystallized ITZ showed higher drug dissolution than untreated ITZ and the highest drug dissolution was observed from the samples recrystallized in the presence of PEG 200,which provided the small plate-shaped crystals with tremendously increased in surface area.However,the increasing of drug dissolution is relatively small,therefore,further development may be required.展开更多
基金the Thailand Research Fund through Thai Basic Research Grant(BRG5680020 to V.B.J.)the Royal Golden Jubilee Ph.D.Program and Mahidol。
文摘Nanocrystals,a carrier-free colloidal delivery system in nano-sized range,is an interesting approach for poorly soluble drugs.Nanocrystals provide special features including enhancement of saturation solubility,dissolution velocity and adhesiveness to surface/cell membranes.Several strategies are applied for nanocrystals production including precipitation,milling,high pressure homogenization and combination methods such as Nano-Edge^(TM),SmartCrystal and Precipitation-lyophilization-homogenization(PLH)technology.For oral administration,many publications reported useful advantages of nanocrystals to improve in vivo performances i.e.pharmacokinetics,pharmacodynamics,safety and targeted delivery which were discussed in this review.Additionally,transformation of nanocrystals to final formulations and future trends of nanocrystals were also described.
基金This work was supported by National Basic Research Program of China(973 Program)(2009CB930300)National Natural Science Foundation of China(81072605)Shenyang Special Fund for Exploration of Intellectual Resources.
文摘We applied a combination of inorganic mesoporous silica material,frequently used as drug carriers,and a natural organic polymer alginate(ALG),to establish a sustained drug delivery system for the poorly water-soluble drug Indomethacin(IND).Mesoporous silica nanospheres(MSNs)were synthesized using an organic template method and then functionalized with aminopropyl groups through postsynthesis.After drug loading into the pores of aninopropyl functionalized MSNs(AP-MSNs),IND loaded AP-MSNs(IND-AP-MSNs)were encapsulated by ALG through the ionic interaction.The effects of surface chemical groups and ALG layer on IND release were systematically studied using scanning electron microscopy(SEM),transmission electron microscopy(TEM),nitrogen adsorption,zetapotential analysis and TGA analysis.The surface structure and surface charge changes of the ALG encapsulated AP-MSNs(ALG-AP-MSNs)were also investigated.The results showed that sustained release of IND from the designed drug delivery system was mainly due to the blockage effect from the coated ALG.We believe that this combination will help designing oral sustained drug delivery systems for poorly water-soluble drugs.
文摘BACKGROUND Pancreatic cancer is a major cause of cancer-related death,with a 5-year overall survival rate being below 5%.The main causes of poor prognosis in pancreatic cancer include easy metastasis,high recurrence rate,and robust drug resistance.Gemcitabine is a first-line drug for patients with unresectable pancreatic cancer.However,due to drug resistance,the clinical effect is not satisfactory.ADAM28 is reported as a tumor promoter in some cancers,but its role in pancreatic cancer and gemcitabine chemoresistance in pancreatic cancer has not been elucidated.AIM To identify if ADAM28 can act as an important target to reverse the gemcitabine drug resistance in pancreatic cancer.METHODS RNA-sequence analysis was applied to explore the potential targets involved in the gemcitabine of pancreatic cancer.SW1990 pancreatic cancer cells were treated with an increased dose of gemcitabine,and the mRNA levels of ADAM28 were evaluated by RT-PCR.The protein and mRNA levels of ADAM28 were confirmed in the gemcitabine resistant and parallel SW1990 cells.The ADAM28 expression was also assessed in TCGA and GEO databases,and the results were confirmed in the collected tumor and adjacent normal tissues.The overall survival(OS)rate and relapse-free survival(RFS)rate of pancreatic cancer patients with high ADAM28 level and low ADAM28 level in TCGA were evaluated with Kaplan-Meier Plotter.Furthermore,the OS rate was calculated in pancreatic cancer patients with high tumor mutation burden(TMB)and low TMB.CCK-8 assay was used to examine the effect of ADAM28 on the viability of SW1990 cells.The ADAM28 and its co-expressed genes were analyzed in the cBioPortal for cancer genomics and subjected to GSEA pathway analysis.The correlations of ADAM28 with GSTP1,ABCC1,GSTM4,and BCL2 were analyzed based on TCGA data on pancreatic cancer.RESULTS RNA-sequence analysis identified that ADAM28 was overexpressed in gemcitabine-resistant cells,and gemcitabine treatment could induce the expression of ADAM28.The mRNA and protein levels of ADAM28 were elevated in gemcitabine-resistant SW1990 cells compared with parallel cells.Also,the expression of ADAM28 was upregulated in pancreatic tumor tissues against normal pancreatic tissues.Notably,ADAM28 was highly expressed in the classical type than in the basal tumor type.Furthermore,the high expression of ADAM28 was associated with low OS and RFS rates.Interestingly,the high levels of ADAM28 was associated with a significantly lower OS rate in the high TMB patients,but not in the low TMB patients.Moreover,overexpression of ADAM28 could reduce the cell viability inhibition by gemcitabine,and knockdown of ADAM28 could enhance the proliferation inhibition by gemcitabine.The GSEA analysis showed that ADAM28 was related to the regulation of drug metabolism,and ADAM28 was significantly positively correlated with GSTP1,ABCC1,GSTM4,and BCL2.CONCLUSION This study demonstrates that ADAM28 is overexpressed in pancreatic cancer,and closely involved in the regulation of gemcitabine resistance.Overexpression of ADAM28 is a novel prognostic biomarker in pancreatic cancer.
基金Financial support from The Thailand Research Fund(grant number BRG5480013)is greatly acknowledged.
文摘To enhance the dissolution of poorly soluble mefenamic acid,self-emulsifying formulation(SEF),composing of oil,surfactant and co-surfactant,was formulated.Among the oils and surfactants studied,Imwitor■ 742,Tween■ 60,Cremophore■ EL and Transcutol■ HP were selected as they showed maximal solubility to mefenamic acid.The ternary phase diagram was constructed to find optimal concentration that provided the highest drug loading.The droplet size after dispersion and drug dissolution of selected formulations were investigated.The results showed that the formulation containing Imwitor■ 742,Tween■ 60 and Transcutol■ HP(10:30:60)can encapsulate high amount of mefenamic acid.The dissolution study demonstrated that,in the medium containing surfactant,nearly 100% of mefenamic acid were dissolved from SEF within 5 min while 80% of drugs were dissolved from the commercial product in 45 min.In phosphate buffer(without surfactant),80% of drug were dissolved from the developed SEF within 5 min while only about 13% of drug were dissolved in 45 min,from the commercial product.The results suggested that the SEF can enhance the dissolution of poorly soluble drug and has a potential to enhance drug absorption and improve bioavailability of drug.
基金supported by Research Committee of University of Macao (MYRG2017-00200-ICMS)Macao Science and Technology Development Fund (FDCT 0013/2018/A1)
文摘Nanoparticles are considered to be a powerful approach for the delivery of poorly watersoluble drugs. One of the main challenges is developing an appropriate method for preparation of drug nanoparticles. As a simple, rapid and scalable method, the flash nanoprecipitation(FNP) has been widely used to fabricate these drug nanoparticles, including pure drug nanocrystals, polymeric micelles,polymeric nanoparticles, solid lipid nanoparticles, and polyelectrolyte complexes. This review introduces the application of FNP to produce poorly water-soluble drug nanoparticles by controllable mixing devices, such as confined impinging jets mixer(CIJM), multi-inlet vortex mixer(MIVM) and many other microfluidic mixer systems. The formation mechanisms and processes of drug nanoparticles by FNP are described in detail. Then, the controlling of supersaturation level and mixing rate during the FNP process to tailor the ultrafine drug nanoparticles as well as the influence of drugs, solvent, anti-solvent, stabilizers and temperature on the fabrication are discussed. The ultrafine and uniform nanoparticles of poorly watersoluble drug nanoparticles prepared by CIJM, MIVM and microfluidic mixer systems are reviewed briefly. We believe that the application of microfluidic mixing devices in laboratory with continuous process control and good reproducibility will be benefit for industrial formulation scale-up.
基金This research was supported by Basic Science Research Program through the National Research Foundation of Korea(NRF)funded by the Ministry of Education,Science and Technology(2012-0001499).
文摘Pharmaceutical particle technology is employed to improve poor aqueous solubility of drug compounds that limits in vivo bioavailability owing to their low dissolution rate in the gastrointestinal fluids following oral administration.The particle technology involves several approaches from the conventional size reduction processes to the newer,novel particle technologies that modify the solubility properties of the drugs and produce solid,powdered form of the drugs that are readily soluble in water and can be easily formulated into various dosage forms.This review highlights the solid particle technologies available for improving solubility,dissolution and bioavailability of drugs with poor aqueous solubility.
文摘Dr. Wei Wu is a professor at the Department of Pharmaceutics, School of Pharmacy, Fudan University, Shanghai, China. His research interest is in the field of oral drug delivery systems and in vivo fate of drug nanocarriers. He and coworkers invented novel water-quenching ACQ fluorescent dyes to probe the in vivo fate of versatile nanoparticles administered via different routes.
文摘Oral dosage forms including tablets and capsules are themost commonly used drug products. For some poorly water-soluble and poorly permeable drugs injectable dosage formscan be used to circumvent the challenges of poor bioavailabil-ity.
基金This work was supported by the National Natural Science Foundation of China(Grant No.50873056 to Y.H.).
文摘The solid dispersion has become an established solubilization technology for poorly water soluble drugs.Since a solid dispersion is basically a drug-polymer two-component system,the drug-polymer interaction is the determining factor in its design and performance.In this review,we summarize our current understanding of solid dispersions both in the solid state and in dissolution,emphasizing the fundamental aspects of this important technology.
文摘In this study,using mesoporous silica for the solubility enhancement of poorly watersoluble drug was investigated.Although the incorporating drug into mesoporous silica is generally performed through the solvent method,the new melting method was proposed in the present study.Fenofibrate,a poorly water-soluble drug,was incorporated into mesoporous silica by solvent method and melting method.The obtained samples were observed by SEM and their physicochemical properties were evaluated by PXRD and DSC measurement.The dissolution and supersaturated property were also investigated.The results from SEM,PXRD and DSC measurement showed that drug could be loaded into pore via the melting method as well as by the solvent method.The drug loaded quantity depended on the pore volume.Drug up to 33%could be incorporated into mesoporous silica and existed in amorphous state.When drug was overloaded or difficulty in incorporation into pore was found,recrystallization of drug occurred at the outer surface of mesoporous silica.From the dissolution test,samples prepared by solvent method and melting method gave the supersaturated drug concentration which sample from melting method showed superior dissolution to the one from solvent method.From this study,drug was efficiently incorporated into mesoporous silica by the melting method which is a simple and solvent-free process,and the aqueous solubility enhancement of poorly watersoluble drug was achieved.
文摘Kaempferia parviflora, a plant in the family Zingiberaceae, has been used in Thai traditional medicines for treating hypertension and promoting longevity with good health and wellbeing. However, its limited aqueous solubility and low dissolution restrict its bioavailability.The aim of the study was therefore to improve the dissolution rate of K. parviflora extracted with dichloromethane(KPD) by solid dispersions. Different water-soluble polymers were applied to improve dissolution of KPD. The solid dispersions in different ratios were prepared by solvent evaporation method. Only hydroxypropyl methylcellulose(HPMC) and polyvinyl alcohol-polyethylene glycol grafted copolymer(PVA-co-PEG) could be used to produce homogeneous, powdered solid dispersions. Physical characterization by scanning electron microscopy, hot stage microscopy, differential scanning calorimetry and powder X-ray diffractometry, in comparison with corresponding physical mixtures, showed the changes in solid state during the formation of solid dispersions. Dissolution of a selected marker,5,7,4′-trimethoxyflavone(TMF), from KPD/HPMC and KPD/PVA-co-PEG solid dispersions was significantly improved, compared with pure KPD. The dissolution enhancement by solid dispersion was influenced by both type and content of polymers. The stability of KPD/HPMC and KPD/PVA-co-PEG solid dispersions was also good after 6-month storage in both longterm and accelerated conditions. These results identified that the KPD/HPMC and KPD/PVAco-PEG solid dispersions were an effective new approach for pharmaceutical application of K. parviflora.
基金Financial support from The Thailand Research Fund(grant number BRG5480013)is greatly acknowledged.
文摘The objective of the present study was to alter the crystal habit of itraconazole(ITZ)by cooling and anti-solvent crystallization and characterize its properties.ITZ was recrystallized in different solvents and the effects of each solvent on morphology of crystals,dissolution behavior and solid state of recrystallized drug particles were investigated.The results revealed that ITZ crystals recrystallized by cooling and anti-solvent crystallization showed the different crystal habits from the untreated ITZ.Using cooling crystallization tended to provide needle-shaped crystals while the crystals obtained from anti-solvent crystallization showed more flaky,plate shape.This indicated the importance of preparation method on nucleation and crystal growth.No change in drug polymorphism was observed,according to determination of thermal property and crystalline state by differential scanning calorimetry and powder X-ray diffractometry,respectively.The recrystallized ITZ showed higher drug dissolution than untreated ITZ and the highest drug dissolution was observed from the samples recrystallized in the presence of PEG 200,which provided the small plate-shaped crystals with tremendously increased in surface area.However,the increasing of drug dissolution is relatively small,therefore,further development may be required.