共查询到20条相似文献,搜索用时 234 毫秒
1.
Abhay Gupta Robert L. Hunt Rakhi B. Shah Vilayat A. Sayeed Mansoor A. Khan 《AAPS PharmSciTech》2009,10(2):495-499
The purpose of the work was to investigate correlation between disintegration and dissolution for immediate release tablets
containing a high solubility drug and to identify formulations where disintegration test, instead of the dissolution test,
may be used as the acceptance criteria based on International Conference on Harmonization Q6A guidelines. A statistical design
of experiments was used to study the effect of filler, binder, disintegrating agent, and tablet hardness on the disintegration
and dissolution of verapamil hydrochloride tablets. All formulation variables, i.e., filler, binder, and disintegrating agent,
were found to influence tablet dissolution and disintegration, with the filler and disintegrating agent exerting the most
significant influence. Slower dissolution was observed with increasing disintegration time when either the filler or the disintegrating
agent was kept constant. However, no direct corelationship was observed between the disintegration and dissolution across
all formulations due to the interactions between different formulation components. Although all tablets containing sodium
carboxymethyl cellulose as the disintegrating agent, disintegrated in less than 3 min, half of them failed to meet the US
Pharmacopeia 30 dissolution criteria for the verapamil hydrochloride tablets highlighting the dependence of dissolution process
on the formulation components other than the disintegrating agent. The results identified only one formulation as suitable
for using the disintegration test, instead of the dissolution test, as drug product acceptance criteria and highlight the
need for systematic studies before using the disintegration test, instead of the dissolution test as the drug acceptance criteria.
The opinions expressed in this work are only of authors and do not necessarily reflect the policy and statements of the FDA. 相似文献
2.
Matěj Novák Tereza Boleslavská Zdeněk Grof Adam Waněk Aleš Zadražil Josef Beránek Pavel Kovačík František Štěpánek 《AAPS PharmSciTech》2018,19(8):3414-3424
The problem of designing tablet geometry and its internal structure that results into a specified release profile of the drug during dissolution was considered. A solution method based on parametric programming, inspired by CAD (computer-aided design) approaches currently used in other fields of engineering, was proposed and demonstrated. The solution of the forward problem using a parametric series of structural motifs was first carried out in order to generate a library of drug release profiles associated with each structural motif. The inverse problem was then solved in three steps: first, the combination of basic structural motifs whose superposition provides the closest approximation of the required drug release profile was found by a linear combination of pre-calculated release profiles. In the next step, the final tablet design was constructed and its dissolution curve found computationally. Finally, the proposed design was 3D printed and its dissolution profile was confirmed experimentally. The computational method was based on the numerical solution of drug diffusion in a boundary layer surrounding the tablet, coupled with erosion of the tablet structure encoded by the phase volume function. The tablets were 3D printed by fused deposition modelling (FDM) from filaments produced by hot-melt extrusion. It was found that the drug release profile could be effectively controlled by modifying the tablet porosity. Custom release profiles were obtained by combining multiple porosity regions in the same tablet. The computational method yielded accurate predictions of the drug release rate for both single- and multi-porosity tablets. 相似文献
3.
Shankar Swaminathan Mayur Sangwai Sharad Wawdhane Pradeep Vavia 《AAPS PharmSciTech》2013,14(1):360-374
The present research work explores formulation design, critical scale-up considerations and bio-equivalence studies of soluble itraconazole (ITZ) in a tablet form using disordered drug delivery approach. Disordered system of ITZ with a lower viscosity grade of hydroxypropyl methyl cellulose (Pharmacoat 603) was developed for the first time and extensively characterised at three different stages, namely development of glass system, pellet coating and tablet compression using advanced analytical techniques. Complete molecular embedment of ITZ resulting in amorphisation was observed and found to be sustained until end of the real-time and accelerated stability studies. Developed formulation exhibited comparative in vitro dissolution profile (similarity factor >70) with reference product (Sporanox, Janssen Pharmaceutica) in simulated gastric fluid without enzymes. Formulation was scaled up in three batches (50,000 tablets/batch) with detailed validation of critical process parameters using process capability index method. Critical scale-up considerations like control of residual solvent content, effect of pellet size on dissolution, process variables in pellet coating, compressibility of coated pellets and cushioning effect required for desired compressibility were thoroughly discussed. Bioequivalence study of single dose of test and reference product in seven healthy human volunteers under fed condition exhibited significant bioequivalence with results (AUClast and AUC∞) lying between 90% confidence interval. With increase in number of subjects to 24, a significant effect on pharmacokinetic parameters of both reference as well as developed ITZ tablets was observed. 相似文献
4.
Gessyka Rayana S. Pereira Stephania F. Taveira Marcilio Cunha-Filho Ricardo Neves Marreto 《AAPS PharmSciTech》2018,19(7):2929-2933
The effects of excipients on the accuracy of tablet subdivision are severely underinvestigated. In this study, placebo tablets were prepared using a combined mixture design of fillers and binders to evaluate the effect of these excipients on subdivision accuracy. The responses assessed were mass loss, mass variation, tablet fragmentation, and increased friability. Dicalcium phosphate dihydrate (DCP) gave rise to more uniform and denser tablets than microcrystalline cellulose (MCC), thus resulting in greater subdivision accuracy. The binder type, hydroxypropylcellulose (HPC) or polyvinylpyrrolidone (PVP), did not affect the subdivision of DCP tablets. On the contrary, the structural similarity between HPC and MCC led to improved subdivision accuracy for MCC tablets. A less accurate subdivision was observed in tablets prepared with a DCP–MCC combination; this finding could be attributed to irregular binder distribution in this matrix. An optimized response was built using desirability analysis. This study helps to illuminate the relationship between fillers and binders to guide formulation scientists in the development of tablets with better subdivision performance. 相似文献
5.
The purpose of this study was to investigate the efficiency of superdisintegrants in promoting tablet disintegration and drug
dissolution under varied media pH. Significant reductions in the rate and extent of water uptake and swelling were observed
for both sodium starch glycolate (Primojel) and croscarmellose sodium (Ac-Di-Sol) in an acidic medium (0.1 N HCl) but not
for crospovidone NF (Polyplasdone XL10), a nonionic polymer. When Primojel and Ac-Di-Sol were incorporated in model formulations,
a significant increase in tablet disintegration time was observed for slowly disintegrating tablets (lactose-based tablets)
but not for the rapidly disintegrating tablets (dicalcium phosphate-based tablets). The dissolution rate of the model drug,
hydrochlorothiazide, was found highly dependent on both tablet disintegration efficiency and the solubility of base material(s)
in the testing medium. A laser diffraction particle size analyzer proved to be an effective tool for determining the intrinsic
swelling of disintegrant particles in different media. Water uptake and swelling were confirmed as 2 important functions of
superdisintegrants. The reduced water uptake and swelling capacity of disintegrants containing ionizable substituents in an
acidic medium can potentially jeopardize their efficiency in promoting tablet disintegration and the drug dissolution rate.
Published: September 20, 2005 相似文献
6.
Ozeki T Katsuyama H Yasuzawa Y Takashima Y Kasai T Eguchi T Kakiuchi H Yuasa H Okada H 《AAPS PharmSciTech》2003,4(3):94-100
This investigation examined the application of acid-treated yeast cell wall (AYC) as a binder functioning as a disintegrant.
Acetylsalicylic acid (ASA) was granulated with AYC, hydroxypropylcellulose (HPC), polyvinylpyrrolidone (PVP), or pullulan
(PUL) and compressed into a tablet in the absence of disintegrant. Particle size and angle of repose of the granules, tensile
strength, disintegration time, and water absorption behavior of the tablets and ASA release profiles from the tablets were
measured. The surface of AYC-granules was observed with a scanning electron microscope. As was the case with the granules
of HPC, PVP, or PUL, D50 of the granules of AYC increased with increasing AYC addition percentage, indicating that it is possible
to granulate ASA with AYC. Tablets incorporating HPC, PVP, and PUL failed to disintegrate within 30 minutes at all percentages
of binder addition because in the case of the HPC, PVP, or PUL tablets in the dissolution medium, water scarcely penetrated
into the inner region of the tablet, causing no disintegration. In the case of the AYC tablets, disintegration was not detected
at 3% or less of AYC. When AYC was equal to or greater than 5%, AYC tablets disintegrated in approximately 4 minutes and rapid
ASA release from the tablets was observed. These results may have been caused by the following. In the case of the AYC 3%
granules, ungranulated aspirin powder remained, but in the case of the AYC 5% granules, ASA powder was granulated and covered
with AYC. Water absorption was observed initially; however, a plateau was reached in the case of the AYC 3%-tablet. In contrast,
in the cases of the AYC 5% and more tablets, water absorption was greater and increased with time. The angle of repose of
the AYC 5% granules was 25.7°, which represented high fluidity. The tablets produced by compressing the granules demonstrated
sufficient tensile strength greater than 0.8 MPa. The tablets rapidly disintegrated and rapid ASA release was obtained. AYC
functioned as a binder at granulation; additionally, AYC served as a disintegrant in the dissolution of drug from the tablets.
These results indicate that AYC affords high utility as a unique pharmaceutical additive possessing contrary functions such
as binding and disintegration. 相似文献
7.
The aim of this study was to identify and optimize the critical process parameters of the newly developed Supercell quasi-continuous
coater for optimal tablet coat quality. Design of experiments, aided by multivariate analysis techniques, was used to quantify
the effects of various coating process conditions and their interactions on the quality of film-coated tablets. The process
parameters varied included batch size, inlet temperature, atomizing pressure, plenum pressure, spray rate and coating level.
An initial screening stage was carried out using a 26−1(IV) fractional factorial design. Following these preliminary experiments, optimization study was carried out using the Box–Behnken
design. Main response variables measured included drug-loading efficiency, coat thickness variation, and the extent of tablet
damage. Apparent optimum conditions were determined by using response surface plots. The process parameters exerted various
effects on the different response variables. Hence, trade-offs between individual optima were necessary to obtain the best
compromised set of conditions. The adequacy of the optimized process conditions in meeting the combined goals for all responses
was indicated by the composite desirability value. By using response surface methodology and optimization, coating conditions
which produced coated tablets of high drug-loading efficiency, low incidences of tablet damage and low coat thickness variation
were defined. Optimal conditions were found to vary over a large spectrum when different responses were considered. Changes
in processing parameters across the design space did not result in drastic changes to coat quality, thereby demonstrating
robustness in the Supercell coating process. 相似文献
8.
The objective of this study was to investigate the effect of lipophilic (Compritol 888 ATO) and hydrophilic components (combination of HPMC and Avicel) on the release of carbamazepine from granules and corresponding tablet. Wet granulation followed by compression was employed for preparation of granules and tablets. The matrix swelling behavior was investigated. The dissolution profiles of each formulation were compared to those of Tegretol CR tablets and the mean dissolution time (MDT), dissolution efficiency (DE %) and similarity factor (f(2) factor) were calculated. It was found that increase in the concentration of HPMC results in reduction in the release rate from granules and achievement of zero-order is difficult from the granules. The amount of HPMC plays a dominant role for the drug release. The release mechanism of CBZ from matrix tablet formulations follows non-Fickian diffusion shifting to case II by the increase of HPMC content, indicating significant contribution of erosion. Increasing in drug loading resulted in acceleration of the drug release and in anomalous controlled-release mechanism due to delayed hydration of the tablets. These results suggest that wet granulation followed by compression could be a suitable method to formulate sustained release CBZ tablets. 相似文献
9.
Khalid K. Abed Ahmed A. Hussein Mowafaq M. Ghareeb Alaa A. Abdulrasool 《AAPS PharmSciTech》2010,11(1):356-361
Diazepam is one of the most prescribed benzodiazepines. The purpose of the present research was to optimize the formulation
of orodispersible tablets of diazepam. Orodispersible tablets of diazepam were prepared using different types of superdisintegrants
(Ac-Di-Sol, sodium starch glycolate, and crospovidone (CP)) and different types of subliming agents (camphor and ammonium
bicarbonate (AB)) at different concentrations and two methods of tablets preparations (wet granulation and direct compression
methods). The formulations were evaluated for flow properties, wetting time, hardness, friability, content uniformity, in vivo disintegration time (DT), release profiles, and buccal absorption tests. All formulations showed satisfactory mechanical
strength except formula F5 which contains camphor and formula F9 which is prepared by direct compression method. The results
revealed that the tablets containing CP as a superdisintegrant have good dissolution profile with shortest DT. The optimized
formula F7 is prepared using 10% CP as a superdisintegrant and 20% AB as a subliming agent by wet granulation method which
shows the shortest DT and good dissolution profile with acceptable stability. This study helps in revealing the effect of
formulation processing variables on tablet properties. It can be concluded that the orodispersible tablets of diazepam with
better biopharmaceutical properties than conventional tablets could be obtained using formula F7. 相似文献
10.
The purpose of this research was to prepare a floating drug delivery system of diltiazem hydrochloride (DTZ). Floating matrix
tablets of DTZ were developed to prolong gastric residence time and increase its bioavailability. Rapid gastrointestinal transit
could result in incomplete drug release from the drug delivery system above the absorption zone leading to diminished efficacy
of the administered dose. The tablets were prepared by direct compression technique, using polymers such as hydroxypropylmethylcellulose
(HPMC, Methocel K100M CR), Compritol 888 ATO, alone or in combination and other standard excipients. Sodium bicarbonate was
incorporated as a gas-generating agent. The effects of sodium bicarbonate and succinic acid on drug release profile and floating
properties were investigated. A 32 factorial design was applied to systematically optimize the drug release profile. The amounts of Methocel K100M CR (X1) and Compritol 888 ATO (X2) were selected as independent variables. The time required for 50% (t50) and 85% (t85) drug dissolution were selected as dependent variables. The results of factorial design indicated that a high level of both
Methocel K100M CR (X1) and Compritol 888 ATO (X2) favors the preparation of floating controlled release of DTZ tablets. Comparable release profiles between the commercial
product and the designed system were obtained. The linear regression analysis and model fitting showed that all these formulations
followed Korsmeyer and Peppas model, which had a higher value of correlation coefficient (r). While tablet hardness had little or no effect on the release kinetics and was found to be a determining factor with regards
to the buoyancy of the tablets.
Published: September 7, 2007 相似文献
11.
There is a growing interest for multiparticulate solid dosage forms such as pellets, because of their several advantages over tablets during drug therapy. It is essential to investigate the drug dissolution process which can be influenced by the composition and manufacturing process technology, too. This study was performed applying experimental design in order to evaluate the effects of independent process variables during high-shear pelletisation, taking the impeller speed (x1) and granulation binder flow rate (x2) as factors into consideration. Theophylline containing pellet formulation was prepared using a matrix consisted of ethylcellulose, microcrystalline cellulose and lactose. Dissolution profiles were modeled by the Weibull function to evaluate the power of process variables. Both process variables were powerful to influence the particle agglomeration. A linear regression was found between the particle size and the diffuse reflectance values after the Kubelka-Munk transformation. Differences in the diffuse reflectance spectra of pellet samples related to particle size offer a fast instrumental method for the in-process control. 相似文献
12.
Ravikanth Kona Raafat M. Fahmy Gregg Claycamp James E. Polli Marilyn Martinez Stephen W. Hoag 《AAPS PharmSciTech》2015,16(1):202-216
The objective of this study is to use near-infrared spectroscopy (NIRS) coupled with multivariate chemometric models to monitor granule and tablet quality attributes in the formulation development and manufacturing of ciprofloxacin hydrochloride (CIP) immediate release tablets. Critical roller compaction process parameters, compression force (CFt), and formulation variables identified from our earlier studies were evaluated in more detail. Multivariate principal component analysis (PCA) and partial least square (PLS) models were developed during the development stage and used as a control tool to predict the quality of granules and tablets. Validated models were used to monitor and control batches manufactured at different sites to assess their robustness to change. The results showed that roll pressure (RP) and CFt played a critical role in the quality of the granules and the finished product within the range tested. Replacing binder source did not statistically influence the quality attributes of the granules and tablets. However, lubricant type has significantly impacted the granule size. Blend uniformity, crushing force, disintegration time during the manufacturing was predicted using validated PLS regression models with acceptable standard error of prediction (SEP) values, whereas the models resulted in higher SEP for batches obtained from different manufacturing site. From this study, we were able to identify critical factors which could impact the quality attributes of the CIP IR tablets. In summary, we demonstrated the ability of near-infrared spectroscopy coupled with chemometrics as a powerful tool to monitor critical quality attributes (CQA) identified during formulation development.KEY WORDS: chemometrics, crushing force, disintegration, near-infrared spectroscopy, partial least square, principal component analysis, quality by design, roller compaction 相似文献
13.
Valsartan orodispersible tablets have been developed at 40-mg dose, with the intention of facilitating administration to patients
experiencing problems with swallowing and hopefully, improving its poor oral bioavailability. Work started with selecting
drug compatible excipients depending on differential scanning calorimetric analysis. A 33 full factorial design was adopted for the optimization of the tablets prepared by freeze-drying technique. The effects of
the filler type, the binder type, and the binder concentration were studied. The different tablet formulas were characterized
for their physical properties, weight variation, disintegration time, surface properties, wetting properties, and in vitro dissolution. Amongst the prepared 27 tablet formulas, formula number 6 (consisting of 4:6 valsartan:mannitol and 2% pectin)
was selected to be tested in vivo. Oral bioavailability of two 40 mg valsartan orodispersible tablets was compared to the conventional commercial tablets after
administration of a single dose to four healthy volunteers. Valsartan was monitored in plasma by high-performance liquid chromatography.
The apparent rate of absorption of valsartan from the prepared tablets (C
max = 2.879 μg/ml, t
max = 1.08 h) was significantly higher than that of the conventional tablets (C
max = 1.471 μg/ml, t
max = 2.17 h), P ≤ 0.05. The relative bioavailability calculated as the ratio of mean total area under the plasma concentration–time curve
for the orodispersible tablets relative to the conventional ones was 135%. The results of the in vivo study revealed that valsartan orodispersible tablets would be advantageous with regards to improved patient compliance, rapid
onset of action, and increase in bioavailability. 相似文献
14.
The purpose of the present study was characterization of microparticles obtained by adsorption of poorly water soluble drug,
meloxicam, on a porous silicate carrier Florite RE (FLR) and development of a tablet formulation using these microparticles,
with improved drug dissolution properties. The study also reveals the use of FLR as a pharmaceutical excipient. Meloxicam
was adsorbed on the FLR in 2 proportions (1∶1 and 1∶3), by fast evaporation of solvent from drug solution containing dispersed
FLR. Drug adsorbed FLR microparticles were evaluated for surface topography, thermal analysis, X-ray diffraction properties,
infrared spectrum, residual solvent, micromeritic properties, drug content, solubility, and dissolution studies. Microparticles
showed bulk density in the range of 0.10 to 0.12 g/cm3. Dissolution of drug from microparticles containing 1∶3, drug∶FLR ratio was faster than microparticles containing 1∶1, drug∶FLR
ratio. These microparticles were used for formulating directly compressible tablets. Prepared tablets were compared with a
commercial tablet. All the prepared tablets showed acceptable mechanical properties. Disintegration time of prepared tablets
was in the range of 18 to 38 seconds, and drug dissolution was much faster in both acidic and basic medium from prepared tablets
as compared with commercial tablet. The results suggest that FLR provides a large surface area for drug adsorption and also
that a reduction in crystallinity of drug occurs. Increase in surface area and reduction in drug crystallinity result in improved
drug dissolution from microparticles.
Published: December 7, 2005 相似文献
15.
Anjali Agrawal Mayur Dudhedia Weibin Deng Kevin Shepard Li Zhong Edward Povilaitis Ewa Zimny 《AAPS PharmSciTech》2016,17(1):214-232
The objective of the study was to identify the extragranular component requirements (level and type of excipients) to develop an immediate release tablet of solid dispersions prepared by hot melt extrusion (HME) process using commonly used HME polymers. Solid dispersions of compound X were prepared using polyvinyl pyrrolidone co-vinyl acetate 64 (PVP VA64), Soluplus, and hypromellose acetate succinate (HPMCAS-LF) polymers in 1:2 ratio by HME through 18 mm extruder. A mixture design was employed to study effect of type of polymer, filler (microcrystalline cellulose (MCC), lactose, and dicalcium phosphate anhydrous (DCPA)), and disintegrant (Crospovidone, croscarmellose sodium, and sodium starch glycolate (SSG)) as well as level of extrudates, filler, and disintegrant on tablet properties such as disintegration time (DT), tensile strength (TS), compactibility, and dissolution. Higher extrudate level resulted in longer DT and lower TS so 60–70% was the maximum amount of acceptable extrudate level in tablets. Fast disintegration was achieved with HPMCAS-containing tablets, whereas Soluplus- and PVP VA64-containing tablets had higher TS. Crospovidone and croscarmellose sodium were more suitable disintegrant than SSG to achieve short DT, and MCC was a suitable filler to prepare tablets with acceptable TS for each studied HME polymer. The influence of extragranular components on dissolution from tablets should be carefully evaluated while finalizing tablet composition, as it varies for each HME polymer. The developed statistical models identified suitable level of fillers and disintegrants for each studied HME polymer to achieve tablets with rapid DT (<15 min) and acceptable TS (≥1 MPa at 10–15% tablet porosity), and their predictivity was confirmed by conducting internal and external validation studies. 相似文献
16.
Double-layered matrix tablets prepared from shellac wax-lutrol were fabricated using a molding technique, and the release of hydrochlorothiazide and propranolol HCl from the inner tablet or outer layer was studied. The simultaneous determination of dual drug release was measured with first derivative UV spectrophotometry. The tablet containing shellac wax as the outer tablet and lutrol as the inner tablet showed more appropriate drug release and the size of the inner layer influenced the rate of drug release. In addition, the aqueous solubility of the drug and the components of the inner tablet or outer layer affected the drug release behavior. Most of the double-layered tablets exhibited the drug-release pattern which fitted well with zero-order kinetic due to the restriction of the release surface. Biphasic drug release pattern was found in the tablet of which the outer layer rapidly eroded. The drug dissolution data from drug-loaded-outer layer could predict the dissolution time for the outer layer of drug-loaded inner part of double-layered matrix tablet. Incorporation of lutrol increased the drug release from shellac wax matrix, and the zero-order release was attained by fabricating it into a double-layered tablet. 相似文献
17.
Heba F. Salem Rasha M. Kharshoum Abdel Khalek A. Halawa 《Journal of liposome research》2018,28(2):149-160
Background: Rosuvastatin (ROS) calcium is the latest synthetic drug in the statin group that has an anti-hyperlipidemic activity. It is available as tablets, and its poor aqueous solubility, slow dissolution rate and low-absorption extent result in less than 20% bioavailability and about 80% being excreted unchanged in the feces without absorption.Objective: To utilize nanotechnology to reformulate ROS as a self-nano-emulsifying drug delivery system (SNEDDS), and utilizing design optimization to fabricate the SNEDDS as a tablet.Methods: The solubility of ROS in different oils, surfactants and co-surfactants was tested. Pseudo-ternary phase diagrams were developed and various SNEDDS formulations were prepared and evaluated regarding globule size, self-emulsification, viscosity and transmittance. The optimized system was examined using transmission electron microscopy. The self-nano-emulsifying tablets were prepared using two types of nano-silica and different percentages of Avicel as a binder and Ac-Di-Sol as a disintegrant. The prepared tablets were evaluated for their physicochemical properties. Bioavailability in human volunteers was assessed.Results: A SNEDDS system was successfully developed with a droplet size range of 15?nm and a composition of 10% Labrafac, 80% Cremophore RH40 and 10% Propylene glycol. The optimized tablet formula contained: hydrophilic nano-silica, 3% Ac-Di-Sol and 30% Avicel. The pharmacokinetic study revealed that the bioavailability was enhanced by more than 2.4-fold compared with the commercially available tablet.Conclusions: Tablets containing SNEDDS loaded with ROS represent a promising novel formula that has higher gastrointestinal absorption and enhanced systemic bioavailability. 相似文献
18.
Andrew L. Fussell Peter Kleinebudde Jennifer Herek Clare J. Strachan Herman L. Offerhaus 《Journal of visualized experiments : JoVE》2014,(89)
Traditional pharmaceutical dissolution tests determine the amount of drug dissolved over time by measuring drug content in the dissolution medium. This method provides little direct information about what is happening on the surface of the dissolving tablet. As the tablet surface composition and structure can change during dissolution, it is essential to monitor it during dissolution testing. In this work coherent anti-Stokes Raman scattering microscopy is used to image the surface of tablets during dissolution while UV absorption spectroscopy is simultaneously providing inline analysis of dissolved drug concentration for tablets containing a 50% mixture of theophylline anhydrate and ethyl cellulose. The measurements showed that in situ CARS microscopy is capable of imaging selectively theophylline in the presence of ethyl cellulose. Additionally, the theophylline anhydrate converted to theophylline monohydrate during dissolution, with needle-shaped crystals growing on the tablet surface during dissolution. The conversion of theophylline anhydrate to monohydrate, combined with reduced exposure of the drug to the flowing dissolution medium resulted in decreased dissolution rates. Our results show that in situ CARS microscopy combined with inline UV absorption spectroscopy is capable of monitoring pharmaceutical tablet dissolution and correlating surface changes with changes in dissolution rate. 相似文献
19.
The effects of plantain starch obtained from the unripe fruit of the plantMusa paradisiaca L. (Musaceae) on the mechanical and disintegration properties of paracetamol tablets have been investigated in comparison with
the effects of corn starch BP using a 23 factorial experimental design. The individual and combined effects of nature of starch binder (N), concentration of starch
binder (C), and the relative density of tablet (RD) on the tensile strength (TS), brittle fracture index (BFI), and disintegration
time (DT) of the tablets were investigated. The ranking of the individual effects on TS was RD>C≫N, on BFI was C≫RD>N and
on DT was N>C>RD. The ranking for the interaction effects on TS and DT was N-C≫N-RD>C-RD, while that on BFI was N-C≫C-RD>N-RD.
Changing nature of starch from a “low” (plantain starch) to a “high” (corn starch) level, increasing the concentration of
starch binding agent from 2.5% to 10.0% wt/wt, and increasing relative density of the tablet from 0.80 to 0.90, led to increase
in the values of TS and DT, but a decrease in BFI. Thus, tablets containing plantain starch had lower tensile strength and
disintegration time values than those containing corn starch, but showed better ability to reduce the lamination and capping
tendency in paracetamol tablet formulation. The interaction between N and C was significantly (P<.001) higher than those between N and RD and between C and RD. There is therefore the need to carefully choose the nature
(N) and concentration (C) of starch used as binding agent in tablet formulations to obtain tablets of desired bond strength
and disintegration properties. Furthermore, plantain starch could be useful as an alternative binding agent to cornstarch,
especially where faster disintegration is required and the problems of lamination and capping are of particular concern.
Published: October 22, 2005 相似文献
20.
The different approaches for targeting orally administered drugs to the colon include coating with pH-dependent polymers,
design of time-release dosage forms, and the utilization of carriers that are degraded exclusively by colonic bacteria. The
aim of the present study was to develop a single unit, site-specific drug formulation allowing targeted drug release in the
colon. Matrix tablets were prepared by wet granulation using cross-linked chitosan (ChI) and chondroitin sulfate (ChS) polysaccharides
as binder and carrier. ChS was used to form polyelectrolyte complexes (PEC) with ChI, and its potential as a colon-targeted
drug carrier was investigated. Indomethacin was used as a model drug. The ChI and ChS PEC was characterized by Fourier transform
infrared spectroscopy (FTIR), differential scanning calorimetry (DSC) and powder X-ray diffraction studies (XRD). The matrix
tablets were tested in vitro for their suitability as colon-specific drug delivery systems. FTIR demonstrated that the PEC forms through an electrostatic
interaction between the protonated amine (NH3+) group of ChI with the free carboxylate (COO−) group and sulfate (SO42−) group of ChS. DSC and XRD indicated that the PEC has different thermal characteristics from ChI or ChS. The dissolution
data demonstrates that the dissolution rate of the tablet is dependent upon the concentration of polysaccharide used as binder
and matrix and time of cross-linking. The study confirmed that selective delivery of indomethacin to the colon can be achieved
using cross-linked ChI and ChS polysaccharides. 相似文献