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1.
R. C. Mashru V. B. Sutariya M. G. Sankalia P. Yagnakumar 《Journal of Thermal Analysis and Calorimetry》2005,82(1):167-170
Summary Solid dispersions were prepared to enhance the dissolution rate of rofecoxib. Differential scanning calorimetry (DSC) and
X-ray diffraction (XRD) were used for the characterization of solid dispersions of polyvinyl pyrrolidone (PVP):talc:drug (3:1:1)
and hydroxypropyl methylcellulose (HPMC):talc:drug (4:1:1). The DSC study indicated that PVP solid dispersion showed formation
of fusion solution while HPMC solid dispersion showed no intermolecular fusion during the preparation of solid dispersions
by spray dry process. The dissolution profiles and the calculated times for 75 and 90% drug release showed that dissolution
rate of rofecoxib was improved in solid dispersions as compared to pure drug and physical mixtures. The DSC and XRD were successfully
employed to find out the crystalline state of drug in the both solid dispersions. PVP solid dispersion gave better dissolution
rate than HPMC solid dispersion. The drug was transformed from crystalline to amorphous form in PVP solid dispersion which
was further conformed by XRD and DSC. The PVP:talc:drug solid dispersion can be used for the dissolution enhancement and thereby
bioavailability of rofecoxib. 相似文献
2.
F I Kanaze E Kokkalou I Niopas M Georgarakis A Stergiou D Bikiaris 《Journal of Thermal Analysis and Calorimetry》2006,83(2):283-290
Purposes of this paper were to prepare and study
new drug delivery systems for both flavanone glycosides and their aglycones
based on solid-dispersion systems. These compounds are poor water soluble
drugs, so an enhancement of their dissolution is a high priority. Solid-dispersion
systems were prepared using PVP, PEG and mannitol as drug carrier matrices.
Characterizations of these dispersions were done by differential scanning
calorimeter (DSC) and X-ray diffraction (XRD). The glass transition (Tg) temperature of PVP was
only recorded in the DSC thermograms of PVP solid-dispersions of both flavanone
glycosides and their aglycones, while in case of PEG and mannitol solid-dispersions
endotherms of both glycosides and aglycones were noticed with low peak intensity,
indicating that high percent of drug is in amorphous state. The XRD patterns
of all PVP solid-dispersions of aglycones show typical amorphous materials,
but XRD patterns of their glycosides reveal the presence of crystalline material.
However, in all solid dispersions shifts in Tg
of PVP as well as Tm
of PEG were observed, indicating the existence of some interactions between
drugs and matrices. SEM and TEM microscopy revealed that PVP/aglycone flavanone
compounds are nanodispersed systems while all the other solid dispersions
are microcrystalline dispersions. The solubility of both flavanone glycosides
and their aglycones was directly affected by the new physical state of solid
dispersions. Due to the amorphous drug state or nano-dispersions in PVP matrices,
the solubility was enhanced and found to be 100% at pH 6.8 in the nano-dispersion
containing 20 mass% of aglycones. Also solubility enhancement was occurred
in solid dispersions of PEG and mannitol, but it was lower than that of PVP
nano-dispersions due to the presence of the drug compounds in crystalline
state in both matrices. 相似文献
3.
The influence of microwave technology on the in vitro dissolution rate and in vivo antihyperglycemic activity of a poorly water soluble drug, repaglinide (RG) was studied. Solid dispersions were prepared by conventional fusion method and microwave method using poloxamer 188. The dispersions were characterized by solubility study, dissolution study, Fourier transform infrared spectroscopy (FT-IR), differential scanning calorimetry (DSC), X-ray powder diffraction (XRD) and scanning electron microscopy (SEM). Microwave generated solid dispersions exhibited remarkable improvement in solubility and dissolution rate compared to that of pure RG. Results of DSC, XRD and SEM study showed conversion of crystalline form of RG to amorphous form. In vivo studies revealed that the microwave generated solid dispersion showed significant improvements in antihyperglycemic activity as compared to RG alone, thus confirming the advantage of improved pharmacological activity of RG by microwave method. In conclusion, microwave method could be considered as simple, efficient and solvent free promising alternative method to prepare solid dispersion of poorly water soluble drug RG with significant enhancement in solubility, dissolution rate and antihyperglycemic activity. 相似文献
4.
Jigar Shah S. Vasanti B. Anroop Hiral Vyas 《Journal of inclusion phenomena and macrocyclic chemistry》2009,63(1-2):69-75
Solid dispersions of valdecoxib were prepared with the objective of dissolution enhancement by melt granulation technique using polyvinyl pyrollidone (PVP K 30) and polyethylene glycol (PEG 4000) alone (1:1) and in combination (1:0.5:0.5). Phase solubility studies showed a linear increase in valdecoxib solubility with increase in polymer concentration in both the cases. The FTIR spectroscopic studies showed the stability of valdecoxib and absence of well defined valdecoxib—PVP K 30–PEG 4000 interaction. Powder X-ray diffraction (XRD) and differential scanning calorimeter (DSC) were used to characterize the solid state of the dispersion, indicated a complete transformation of drug from crystalline to amorphous form. In vitro dissolution studies performed in 0.1 N HCl showed a significant enhance in dissolution rate when PEG 4000 and PVP K 30 were used in combination. Improved drug dissolution by both the carriers may be attributed to the improved wettability, reduction in drug crystallinity and solubilizing effects from solid dispersions of valdecoxib. Accelerated stability studies of solid dispersion with PVP K 30 and PEG 4000 does not show any significant change in the drug content and dissolution profile in 6 months study period. This study concluded that the dissolution rate of valdecoxib can be modulated by appropriate levels of hydrophilic carriers. 相似文献
5.
Roberta Censi Valentina Martena Ela Hoti Ledjan Malaj Piera Di Martino 《Journal of Thermal Analysis and Calorimetry》2014,115(3):2439-2446
Nicergoline, a semisynthetic ergot derivative, which, in its crystalline state, is insoluble in water, was dispersed in polyvinylpyrrolidone K30 (PVP K30) to improve drug particle dissolution. Preformulation studies were carried out initially by differential scanning calorimetry and X-ray powder diffraction in order to predict the conditions and the possibility to actually obtain solid dispersions by mixing the two components at different proportions. Solid dispersions were finally prepared by dissolving nicergoline and PVP K30 in chloroform that was next evaporated under reduced pressure. Under these conditions, an amorphous powder was recovered in every proportion of the two components. Nicergoline demonstrated to be physically and chemically stable for 1 year. The dissolution studies revealed a very high dissolution rate of nicergoline from solid dispersions only lower than the pure amorphous form. This is the consequence of the molecular dispersion of nicergoline in the polymer that enhances the rate of drug release from the polymer. 相似文献
6.
Boghra RJ Kothawade PC Belgamwar VS Nerkar PP Tekade AR Surana SJ 《Chemical & pharmaceutical bulletin》2011,59(4):438-441
The objective of present work was to enhance the solubility and bioavailability of poorly aqueous soluble drug Irbesartan (IBS). The solid dispersions were prepared by spray drying method using low viscosity grade HPMC E5LV. Prepared solid dispersions were characterized by dissolution study, fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), differential scanning calorimetry (DSC) and X-ray diffraction studies (XRD). Results of the SEM, DSC and XRD study showed the conversion of crystalline form of IBS to amorphous form. The dissolution rate was remarkably increased in case of solid dispersion compared to pure IBS. Solubility and stability of solid dispersion was increased due to surfactant and wetting property, slowing devitrification and having anti-plasticization effect of HPMC E5LV. In vivo studies were performed in healthy rabbits (New Zealand grey) and compared with plain IBS. Solid dispersions showed increase in relative bioavailability than the plain IBS suspension. In conclusion, the prepared solid dispersions showed remarkable increase in solubility, dissolution rate and hence bioavailability of poorly water soluble drug Irbesartan. 相似文献
7.
Y. Yoshihashi H. Iijima E. Yonemochi K. Terada 《Journal of Thermal Analysis and Calorimetry》2006,85(3):689-692
The physical
stability of amorphous drug in solid dispersion was estimated using differential
scanning calorimetry (DSC). Tolbutamide (TB) and flurbiprofen (FBP) were selected
as insoluble drugs in water. Polyvinylpyrrolidone (PVP) was selected as a
polymer for solid dispersion. Solid dispersions of various ratios of TB or
FBP and PVP-K25 were prepared by solvent evaporation method and the induction
period of crystallization from amorphous drug in solid dispersion was measured
by DSC. Compared with FBP, the induction period of crystallization from TB
was delayed by an addition of PVP. The improvement of the physical stability
by the addition of PVP-K25 was estimated from the activation energy of diffusion
of drug molecules and the interfacial free energy between drug crystal and
supercooled liquid of drug in solid dispersion. From thses results, the hindrance
of the diffusivity of the drug molecule might be mainly affected the delay
of the induction period of crystallization of TB and FBP. 相似文献
8.
Bin Li Lindsay A. Wegiel Lynne S. Taylor Kevin J. Edgar 《Cellulose (London, England)》2013,20(3):1249-1260
Resveratrol is a highly biologically active phytoalexin, found in many plant materials that are common elements of the human diet, such as grapes, nuts, and red wine. The therapeutic or disease preventative potential of this natural polyphenolic antioxidant has been limited in part due to its poor aqueous solubility and low oral bioavailability. We hypothesized that solid dispersion of resveratrol (Res) in cellulose derivative matrices might afford amorphous dispersions, from which supersaturated Res solutions would be produced in the human gastrointestinal (GI) tract, resulting in higher Res bioavailability. We carried out structure–property studies employing cellulose esters with a range of physical characteristics but possessing features suitable for use in amorphous solid dispersions: carboxymethylcellulose acetate butyrate (CMCAB), hydroxypropylmethylcellulose acetate succinate (HPMCAS) and cellulose acetate adipate propionate (CAAdP). The cellulose derivative results were compared with those of a negative control, pure crystalline Res, and a positive control, Res/poly(vinylpyrrolidinone) (PVP). Solid dispersions were characterized by powder X-ray diffraction (XRPD), modulated differential scanning calorimetry (MDSC), nuclear magnetic resonance (NMR) and Fourier transform infrared spectroscopy (FT-IR) of solid dispersions. HPMCAS and PVP solid dispersions afforded faster and more complete Res release at pH 6.8; however Res is also released from PVP matrices at pH 1.2. The carboxyl-containing cellulose derivatives release Res to only a small extent at pH 1.2. This combination of solution and solid phase stabilization against crystallization, and pH-triggered drug release makes these cellulose esters attractive candidates for Res bioavailability enhancement. 相似文献
9.
Chlorpheniramine (CPM) maleate was prepared as a series of resinates by the batch method. The several resinates were investigated by differential scanning calorimetry (DSC), X-ray powder diffraction (XRPD) and infrared (IR) spectrometry. The results from DSC and XRPD showed that the molecular state of the entrapped drug changed from the crystalline to amorphous state. IR spectra indicated that only CPM species was entrapped in the resinates. Moreover, it also showed that the positively charged amine group of the drug interacted with the sulfonate groups of the resin by ionic association. The dissolution of the drug and resinates was also studied where it was found that the dissolution of the resinates was retarded by their crosslinked structure and markedly affected by the quantity of resin. 相似文献
10.
A. C. Preetham 《Journal of Dispersion Science and Technology》2013,34(6):778-783
An attempt has been made to enhance solubility and dissolution of sirolimus by solid dispersion and complexation technique using various hydrophilic excipients. Sirolimus an immunosuppressant agent has low bioavailability due to its low aqueous solubility. Solid dispersion of sirolimus in PEG-6000, Poloxamer-188, and Mannitol were prepared by fusion and solvent evaporation method. Beta-CD complexation of sirolimus was prepared by kneading method. In vitro dissolution studies were carried out in 0.4% SLS in water, which showed that the solid dispersion containing PEG 6000 (1:1), which was prepared by solvent evaporation method, showed faster dissolution rate than the other formulations and β-cyclodextrin complex. Solid dispersions containing PEG 6000 was further investigated by x-ray powder diffraction, differential scanning calorimetry (DSC), and FTIR. X-ray powder diffraction and DSC patterns suggested that the drug state changed from crystalline to amorphous form in the formulation. 相似文献
11.
Solid dispersions (SDs) of ibuprofen (IBU) were prepared with four carriers: Kollidon 25, Kollidon 30, Kollidon VA64, and Kollidon CL, using a newly developed pulse combustion dryer system, HYPULCON. Physicochemical properties of the SDs obtained were investigated by differential scanning calorimetry (DSC), powder X-ray diffraction (PXRD), scanning electron microscope (SEM), and Fourier transformation IR spectroscopy (FT-IR). Powder X-ray diffraction (PXRD) showed that the crystal diffraction peaks of IBU in SDs disappeared completely, and in differential scanning calorimetry (DSC) curves, the endothermic peaks of IBU in SDs were not observed. Fourier transformation IR spectroscopy (FT-IR) proved that interactions between the drug and carrier existed. These findings demonstrated that IBU changed to an amorphous form in the SDs with the four carriers using the pulse combustion dryer system. The dissolution property of IBU in the SDs was markedly enhanced. The dissolution test showed that after 5 min of dissolution, the concentrations of IBU in the SDs with Kollidon CL as the carrier was 43.81 mug/ml, corresponding to 13.0 times that of pure IBU. So, it is demonstrated that the pulse combustion dryer system is very useful for preparing SDs of IBU with Kollidon of different grades as carriers. 相似文献
12.
R. Ambrus Z. Aigner L. Catenacci G. Bettinetti P. Szabó-Révész M. Sorrenti 《Journal of Thermal Analysis and Calorimetry》2011,104(1):291-297
In view of the poor aqueous solubility of nifluminic acid (NIF), the aim of this article was to improve its solubility and
dissolution rate through the preparation of formulations based on hydroxypropyl β-cyclodextrin (HPβCD) and polyvinylpyrrolidone
K25 (PVP K25), a combination of carriers which has been advantageously used for a similar purpose with various hydrophobic
drugs. Ternary systems of NIF, HPβCD, and PVP K25 were prepared in different drug to CD to PVP ratios by physical mixing,
kneading, microwave irradiation, and co-evaporation. Differential scanning calorimetry, thermogravimetric analysis, hot stage
microscopy, Fourier transform infrared spectroscopy, and X-ray powder diffractometry were used to investigate the resulting
solid-state interactions. The results showed that the solid state of the drug in the amorphous or crystalline ternary combinations
influenced both the solubility and the dissolution rate of NIF. 相似文献
13.
Verheyen S. Blaton N. Kinget R. Van den Mooter G. 《Journal of Thermal Analysis and Calorimetry》2003,73(2):563-576
The effect of grinding on the physical properties and pharmaceutical performance of solid dispersions made of poly(ethylene)
glycol 6000 (PEG6000) and temazepam or diazepam was studied using differential scanning calorimetry (DSC), X-ray powder diffraction
and dissolution experiments. DSC-analysis of flash-cooled dispersions revealed that amorphous PEG present immediately after
grinding crystallised upon aging mainly into the twice folded modification and to a small extent into the extended form. DSC-analysis
of dispersions kept in the slab form for 1 month and subsequently ground, revealed that in the abscence of the grinding impulse
crystallisation of PEG6000 takes place in the same way as in dispersions ground immediately after preparation and then aged
for 1 month. Grinding solid dispersions immediately after preparation resulted in superior dissolution properties compared
with solid dispersions kept in the monolith-slab form and subsequently ground. This difference in dissolution properties was
found to be attributed to the drug and not to the polymer, more precisely, it was suggested that the drug particle size in
ground dispersions was smaller than in dispersions kept in the slab form and subsequently ground. These findings suggest that
grinding of solid dispersions immediately after preparation is the preparation method of choice instead of liquid filling
of hard gelatin capsules resulting in monoliths.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
14.
Agata Górniak Bożena Karolewicz Ewa Żurawska-Płaksej Janusz Pluta 《Journal of Thermal Analysis and Calorimetry》2013,111(3):2125-2132
The objective of the present investigation was to study the effect of eutectic formation on in vitro dissolution of simvastatin (SIM) released from mixtures with acetylsalicylic acid (ASA) prepared by a grinding method. SIM–ASA mixtures were characterized by means of differential scanning calorimetry (DSC), infrared spectroscopy (IR), X-ray powder diffractometry (XRPD), and in vitro dissolution tests. IR spectroscopy and XRPD studies indicated no interaction between SIM and ASA in the solid state. The DSC investigation has revealed that SIM and ASA form a simple eutectic system containing 66.6 % w/w of SIM at the eutectic point. In vitro dissolution studies of SIM and its mixtures with ASA were carried out. The eutectic mixture shows an appreciable increase in the dissolution rate in comparison with other ratios and SIM in 0.5 % w/v sodium lauryl sulfate. The dissolution enhancement of SIM was related to the effective wetting of the drug particles with a significantly reduced size released from eutectic composition. In conclusion, dissolution of SIM can be enhanced through eutectic formation with ASA by means of simple mechanical activation (a grinding method). 相似文献
15.
Newa M Bhandari KH Kim JO Im JS Kim JA Yoo BK Woo JS Choi HG Yong CS 《Chemical & pharmaceutical bulletin》2008,56(4):569-574
To improve its solubility, dissolution, and bioavailability; Ibuprofen-polyethylene glycol 8000 (PEG 8000) solid dispersions (SDs) with different drug loadings were prepared, characterized by scanning electron microscopy (SEM) and differential scanning calorimetry (DSC), and evaluated for solubility, in-vitro release, and oral bioavailability of ibuprofen in rats. Loss of individual surface properties during melting and solidification as revealed by SEM micrographs indicated the formation of effective SDs. Absence or shifting towards the lower melting temperature of the drug peak in SDs and physical mixtures in DSC study indicated the possibilities of drug-polymer interactions. Quicker release of ibuprofen from SDs in rat intestine resulted in a significant increase in AUC and C(max), and a significant decrease in T(max) over pure ibuprofen. Preliminary results of this study suggested that the preparation of ibuprofen SDs using PEG 8000 as a meltable hydrophilic polymer carrier could be a promising approach to improve solubility, dissolution and bioavailability of ibuprofen. 相似文献
16.
A new benzofuroquinoline derivative, 3,9-bis(N,N-dimethylcarbamoyloxy)-5H-benzofuro[3,2-c]quinoli ne-6-one (KCA-098), shows poor oral absorption due to practical insolubility in water. In this study, a co-grinding technique employing a water-soluble polymer was used for improvement of the dissolution rate of KCA-098. Powder X-ray diffraction patterns and IR spectra of KCA-098 showed the conversion of the drug from a crystal state to an amorphous state by grinding with a polymer such as hydroxypropyl cellulose (HPC-SL) or polyvinylpyrrolidone (PVP K30). The particle size of KCA-098 was remarkably reduced to a submicron size by grinding with HPC-SL. The co-ground mixture with HPC-SL showed a rapid dissolution rate and maintained supersaturation for more than 1 h. On the other hand, the co-ground mixture with PVP K30 showed rapid dissolution and supersaturation for a shorter period. These data suggest that the rapid dissolution rate was obtained by the conversion of the drug particles from a crystal to amorphous state by grinding with water-soluble polymers and that a reduction in particle size to the submicron level led to the maintenance of supersaturation due to good dispersion. 相似文献
17.
The present investigation studied a novel extended release system of promethazine hydrochloride (PHC) with acrylic polymers Eudragit RLPO and Eudragit RS100 in different weight ratios (1 : 1 and 1 : 5) using coevaporation and coprecipitation techniques. Solid dispersions were characterized by Fourier-transformed infrared spectroscopy (FT-IR), Differential scanning calorimetry (DSC), Powder X-ray diffractometry (PXRD), Nuclear magnetic resonance (NMR), Scanning electron microscopy (SEM) as well as solubility and in vitro dissolution studies in 0.1 n HCl (pH 1.2), double distilled water and phosphate buffer (pH 7.4). Adsorption test from drug solution to solid polymers were also performed. Selected solid dispersion system was subjected to direct compression and compressed tablets were evaluated for in vitro dissolution studies. The progressive disappearance of drug peaks in thermotropic profiles of coevaporates were related to increasing amount of polymers while SEM studies suggested homogenous dispersion of drug in polymer. Eudragit RLPO had a greater adsorptive capacity than Eudragit RS100 and thus its coevaporates in 1 : 5 ratio exhibited higher dissolution rate with 91.90% drug release for 12 h. Among different formulations, tablets prepared by Eudragit RLPO coevaporates (1 : 5) displayed extended release of drug for 12 h with 90.87% release followed by zero order kinetics (r(2)=0.9808). 相似文献
18.
Narra Kishore U. M. Dhanalekshmi M. D. Raja Saranya Bhavani 《Journal of Dispersion Science and Technology》2013,34(1):96-102
Solid-lipid nanoparticles (SLNs) are an interesting nanoparticulate delivery system. The present work was carried out with the aim to develop a prolonged release solid-lipid nanoparticulate system for the drug using aceclofenac. Aceclofenac-loaded solid-lipid nanoparticles (ACSLNs) was prepared by hot high pressure homogenization technique. Tripalmitin was used as the lipid core. Surfactants (Poloxamer 188, Tween 80, and soya lecithin) and co-surfactant (sodium tauro glycholate) were used in the formulations. The prepared ACSLN formulations were characterized for encapsulation efficiency (EE), photon correlation spectroscopy (PCS), scanning electron microscopy (SEM), and x-ray diffraction (XRD). From these studies, mean particle diameter of the formulation prepared with combination of surfactants (Poloxmer 188 and Tween 80) was about 200 nm with spherical morphology and amorphous nature. Higher EE was obtained with SLNs prepared using combination of soya lecithin and poloxmer 188. The organization and distribution of the ingredients in the nanoparticulate system were studied by differential scanning calorimetry (DSC) and the results showed that the drug is incorporated into the solid matrix. The prepared formulations demonstrated favorable in vitro prolonged release characteristics. Experimental in vitro release data were substituted in available mathematical models to establish the release kinetics of ACSLNs and it was found to follow first-order kinetics and Higuchi diffusion mechanism. Our results suggest that these SLN formulations could constitute a promising approach for the drug delivery of aceclofenac. 相似文献
19.
Polymorphic transition and stability problems during amorphous drug formulation are the major limiting factors in pharmaceutical technology. The purpose of the study was to evaluate the ability of polyglycolized glycerides (Gelucire) in protection of amorphous form of drug during compression and shelf life with lower proportion. Amorphous etoricoxib (AET) was prepared by spray drying technique. Tablets of AET and melt granules of AET (MG-AET) with Gelucire 50/13 were prepared. Tablets parameters like hardness, disintegration and content uniformity were evaluated. Tablets were evaluated immediately after compression and on storage for 3 months at ambient conditions to determine degree of transformation using X-ray powder diffraction (XRPD), differential scanning calorimetry (DSC) and dissolution profiles. Spray drying yielded the amorphous etoricoxib. Content uniformity in the tablet was in between 95 to 105%. Other parameters like disintegration and hardness were well within the limits. The results showed significant difference in the degree of crystallinity between AET tablet and MG-AET tablet. MG-AET tablet showed absence of crystallinity after 3 months storage. The reason could be formation of hydrogen bonding between the Gelucire and AET. Also Gelucire can be tableted very easily under low pressure and showed elastic recovery. Gelucire yielded a soft embedding during tableting, which prevented the polymorphic transformation. Polyglycolized glycerides (Gelucire 50/13) are able to protect amorphous etoricoxib during compression. As excipient required is low, it became possible to prepare tablet formulation as compared to other excipient like polyvinylpyrrolidon (PVP). 相似文献
20.
The purpose of this study was to investigate the effects of alkalizers in dissolution rate and crystal structure of valsartan (VAL) in Poloxamer 407 (POX)-based solid dispersions (SD). VAL, a poorly-water soluble drug was selected as a model drug because of its low solubility at low pH. The POX-based SDs containing alkalizers (Na?CO?, MgO, meglumine and arginine) were prepared by melting method. The dissolution tests were performed using the United States Pharmacopeia (USP) paddle II method in enzyme-free simulated gastric fluid (pH 1.2) for 2 h. Microenvironmental pH (pH(M)) was examined potentiometrically by using a surface pH electrode. Dissolution rate of SD incorporating Na?CO? was drastically increased. The differential scanning calorimetry (DSC) and powder X-ray diffraction (PXRD) data indicated that crystalline structure of VAL in SD was transformed to amorphous form by the addition of alkalizers but could not explain the differences in the dissolution rates. The molecular interaction between VAL and Na?CO? was observed in the Fourier transform infrared spectroscopy (FT-IR) spectra by the shift of C=O band from 1732 to 1719 cm?1 and the disappearance of carbonyl group at 1598 cm?1. Furthermore, Na?CO? efficiently modulated pH(M) by providing a favorable microenvironment for drug dissolution. A combination of SD method and use of alkalizer is a promising approach to modulate release rate of poorly water-soluble and ionizable drug with an aid of changes of drug crystallinity, molecular interaction and pH(M). 相似文献