首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 35 毫秒
1.
The objective of this study was to prepare and evaluate in vitro the bioadhesive gels of 5-Fluorouracil (FU) for the treatment of oropharyngeal cancer. In preformulation study, the physicochemical interactions between FU and polymers were investigated by X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectrophotometry, and differential scanning calorimetry (DSC). According to FTIR, XRD, and DSC studies, the drug did not show any evidence of an interaction with the polymers used and was present in an unchanged state. The gel formulations containing FU were prepared by using Poloxamer 407, HPMC K 15 M, and Gantrez S-97 (polymethylvinylether-co-maleic anhydride). The formulations contained Poloxamer 407 (16-18% w/w) either alone or in combination with HPMC K 15 M and Gantrez S-97. The bioadhesiveness of the gels was found to increase with increasing proportion of HPMC K 15 M and Gantrez S-97. In vitro release studies indicated that release could be sustained up to 8 hr. The permeability coefficients (Kp) of gel across cellulose membrane and buccal mucosal membrane were 1.06 x 10(-4) cm/s and 3.94 x 10(-5) cm/s, respectively, and differed significantly ( p < 0.05). Increasing temperature increased the drug release by increasing drug diffusion despite increase in viscosity. The pH of the release medium showed a very slight effect on the release of FU. Mathematical modeling of in vitro dissolution data indicated the best fitting with Korsemeyer-Peppas model and the drug release kinetics primarily as non-Fickian diffusion.  相似文献   

2.
李桂玲  李眉 《中国药学》2007,16(2):90-95
目的研制以普朗尼克F127为主要基质的喷昔洛韦制剂,以提高其眼部生物利用度。方法通过将HPMC K4M或卡波姆934P与普朗尼克F127复合使用,制备了喷昔洛韦的温度敏感原位凝胶。以胶凝温度、流变学、药物释放特性、药代动力学及眼部刺激性等为指标进行筛选,得到最优化处方。结果使用HPMC K4M或者卡波姆934P均能降低凝胶的胶凝温度,略微增加其粘度,延缓体系中药物的释放速率;药物释放为非Fick扩散;所有处方均未表现出眼部刺激或对角膜的损伤;含卡波姆934P和普朗尼克F127的凝胶体系的眼部生物利用度最高。结论含普朗尼克F127的喷昔洛韦制剂能够以滴眼液的形式给药,而达到眼部温度时可形成凝胶;体内外评价结果表明,含有HPMC K4M或卡波姆934P以及低浓度普朗尼克F127(12%)的喷昔洛韦制剂,提高了药物在眼部的生物利用度,是一种很有前景的眼部给药系统。  相似文献   

3.
Lisinopril is an angiotensin-converting enzyme (ACE) inhibitor, primarily used for the treatment of hypertension, congestive heart failure, and heart attack. It belongs to BCS class III having a half-life of 12 hrs and 25% bioavailability. The purpose of the present work was to develop a press-coated, floating-pulsatile drug delivery system. The core tablet was formulated using the super-disintegrants crosprovidone and croscarmellose sodium. A press-coated tablet (barrier layer) contained the polymer carrageenan, xanthan gum, HPMC K4M, and HPMC K15M. The buoyant layer was optimized with HPMC K100M, sodium bicarbonate, and citric acid. The tablets were evaluated for physical characteristics, floating lag time, swelling index, FTIR, DSC, and in vitro and in vivo behavior. The 5% superdisintgrant showed good results. The FTIR and DSC study predicted no chemical interactions between the drug and excipients. The formulation containing xanthan gum showed drug retaining abilities, but failed to float. The tablet containing HPMC K15M showed a high swelling index. The lag time for the tablet coated with 200 mg carrageenan was 3±0.1 hrs with 99.99±1.5% drug release; with 140 mg HPMC K4M, the lag time was 3±0.1 hrs with 99.71±1.2% drug release; and with 120 mg HPMC K15M, the lag time was 3±0.2 hrs with 99.98±1.7% drug release. The release mechanism of the tablet followed the Korsmeyer-Peppas equation and a first-order release pattern. Floating and lag time behavior have shown good in vitro and in vivo correlations.  相似文献   

4.
This study developed and examined the characterization of Benzidamine hydrochloride (BNZ) bioadhesive gels as platforms for oral ulcer treatments. Bioadhesive gels were prepared with four different hydroxypropylmethylcellulose (HPMC) types (E5, E15, E50 and K100M) with different ratios. Each formulation was characterized in terms of drug release, rheological, mechanical properties and adhesion to a buccal bovine mucosa. Drug release was significantly decreased as the concentration and individual viscosity of each polymeric component increased due to improved viscosity of the gel formulations. The amount of drug released for the formulations ranged from 0.76?±?0.07 and 1.14?±?0.01 (mg/cm2?±?SD). Formulations exhibited pseudoplastic flow and all formulations, increasing the concentration of HPMC content significantly raised storage modulus (G′), loss modulus (G″), dynamic viscosity (?′) at 37°C. Increasing concentration of each polymeric component also significantly improved the hardness, compressibility, adhesiveness, cohesiveness and mucoadhesion but decreased the elasticity of the gel formulations. All formulations showed non-Fickian diffusion due to the relaxation and swelling of the polymers with water. In conclusion, the formulations studied showed a wide range of mechanical and drug diffusion characteristics. On the basis of the obtained data, the bioadhesive gel formulation which was prepared with 2.5% HPMC K 100M was determined as the most appropriate formulation for buccal application in means of possessing suitable mechanical properties, exhibiting high cohesion and bioadhesion.  相似文献   

5.
Gastroretentive tablets of propranolol hydrochloride were developed by direct compression method using citric acid and sodium bicarbonate as the effervescent base. Hydroxypropyl methylcellulose; HPMC K15M was used to prepare the floating tablets to retard the drug release for 12h in stomach. Na-carboxymethyl cellulose (NaCMC) or carbopol 934P was added to alter the drug release profile or the dimensional stability of the formulation. Dicalcium phosphate (DCP) was used as filler. Formulations were evaluated for floating lag time, duration of floating, dimensional stability, drug content and in vitro drug release profile. The formulations were found to have floating lag time less than 1min. It was found that the dimensional stability of the formulations increase with increasing concentration of the swelling agent. The release mechanism of propranolol hydrochloride from floating tablets was evaluated on the basis of Peppas and Higuchi model. The ana value of the formulations ranged from 0.5201 to 0.7367 (0.5相似文献   

6.
The aim of the study was to develop intraoral films (IOFs) of loratadine and to assess the storage conditions by dynamic vapour sorption studies. The excipient selection was guided by drug excipient compatibility studies and the incompatibility of loratadine with dibutylphathalate and Tween20 was confirmed by Electro-spray Ionization Mass Spectrometry. Thus intaroral films were developed using HPMC E-15 LV and polyvinyl alcohol (PVA) as lone and mixed film formers to get eighteen formulations (F1- F18) that varied in the type and amount of plasticizer used. Four formulations selected on the basis of pharmacotechnical characteristics were improvised by inclusion of Poloxamer407 that lowered the dissolving time to the tune of 36–55%. Dynamic vapour sorption studies of the improvised films (PF1-PF4) demonstrated an increase of 2% by weight at 50% relative humidity (RH) and 25°C suggesting storage of the films below the stated conditions. In vitro drug release studies in phosphate buffer pH 6.8 demonstrated more than 94% cumulative drug release from the formulations. Analysis of model independent parameters identified PF2 as the best formulation that was nine times superior in its dissolution efficiency to Lorafast tablets®.  相似文献   

7.
Delivery of orally compromised therapeutic drug molecules to the systemic circulation via buccal route has gained a significant interest in recent past. Bioadhesive polymers play a major role in designing such buccal dosage forms, as they help in adhesion of designed delivery system to mucosal membrane and also prolong release of drug from delivery system. In the present study, HPMC (release retarding polymer) and mannitol (diluent and pore former) were used to prepare bioadhesive and controlled release buccal discs of buspirone hydrochloride (BS) by direct compression method. Compatibility of BS with various excipients used during the study was assessed using DSC and FTIR techniques. Effect of mannitol and HPMC on drug release and bioadhesive strength was studied using a 32 factorial design. The drug release rate from delivery system decreased with increasing levels of HPMC in formulations. However, bioadhesive strength of formulations increased with increasing proportion of HPMC in buccal discs. Increased levels of mannitol resulted in faster rate of drug release and rapid in vitro uptake of water due to the formation of channels in the matrix. Pharmacokinetic studies of designed bioadhesive buccal discs in rabbits demonstrated a 10-fold increase in bioavailability in comparison with oral bioavailability of buspirone reported.  相似文献   

8.

Purpose

The objectives of this study were to develop once-a-day oral controlled-release tablets of quetiapine fumarate (QF) and to determine the effect of polymer type, viscosity grade, polymer ratio, and polymer rheological properties on the rate of QF release from hydroxypropyl methylcellulose (HPMC) matrix tablets.

Methods

Tablets were prepared from low-viscosity-grade HPMC K100LV (K100LV), high-viscosity-grade HPMC K4M (K4M), Compritol® HD5 ATO (PEGylated glyceryl behenate (PGB)), and binary combinations of these polymers. In vitro drug release from all tablets was evaluated over 24 h.

Results

In vitro drug release studies revealed that formulations containing K100LV/K4M and PGB/K4M at a ratio of 170:70 resulted in similar release profiles which extended for 24 h (f2 > 50). QF release kinetics followed either diffusion, anomalous transport, case II transport, or super case II transport, as fitted by the Korsmeyer-Peppas model. Tablet swelling and erosion studies were consistent with dissolution profiles. A linear relationship between % swelling and % QF released was observed in tablets containing K4M alone or in combination with K100LV or PGB, indicating the direct role of polymer swelling in controlling the mechanism of drug release. The viscoelastic properties of single and binary polymeric gels made with the three polymers (K100LV, K4M, and PGB) corroborated the in vitro release studies of QF tablets.

Conclusions

Our results provide evidence that blending polymers with different viscosities and hydrophilicities can result in unique matrices with tunable release profiles.
  相似文献   

9.
Buccoadhesive tablets of carvedilol were prepared using HPMC K4M, HPMC K15M and Carbopol 934 as mucoadhesive polymers. Fifteen formulations were developed with varying concentrations of polymers. Formulations of the BC or BD series were composed of HPMC K4M or HPMC K15M in ratios of 1:1 to 1:5 whereas in the BE series Carbopol 934 was used (1:0.25 to 1:1.50). The formulations were tested for in vitro drug release, in vitro bioadhesion, moisture absorption and in vitro drug permeation through porcine buccal mucosa. Formulation BC3 showed maximum release of the drug (88.7 +/- 0.4%) with the Higuchi model release profile and permeated 21.5 +/- 2.9% of the drug (flux 8.35 +/- 0.291 microg h(-1)cm(-2)) permeation coefficient 1.34 +/- 0.05 cm h(-1)) through porcine buccal membrane. BC3 formulation showed 1.62 +/- 0.15 N of peak detachment force and 0.24 +/- 0.11 mJ of work of adhesion. FTIR results showed no evidence of interaction between the drug and polymers. XRD study revealed that the drug is in crystalline form in the polymer matrix. The results indicate that suitable bioadhesive buccal tablets with desired permeability could be prepared.  相似文献   

10.
A suitable topical formulation of mefenamic acid was developed in order to eliminate the gastrointestinal disorders associated with its oral administration. Drug coprecipitates prepared with different polymers at various drug-to-polymer ratios improved drug solubility and dissolution compared to pure drug and physical mixtures. PVP polymers (ratio 1:4) produced the best results. Aqueous ionic cream, ointments of absorption and water soluble bases and gels of methylcellulose, carboxymethylcellulose sodium, HPMC, Carbopol® 934 and 940, and Pluronic® F127 bases containing 1–10% drug as coprecipitates of PVP polymers (1:4) were prepared. The highest drug release was achieved at 1% drug concentration from water soluble base and methylcellulose among cream/ointment and gel bases, respectively. Gels, in general yielded better release than creams/ointments. All tested medicated creams/ointments exhibited plastic flow while all gels conformed to pseudoplasticity. Most of them showed thixotropy, a desired property of topical preparations. Stability studies revealed that HPMC and methylcellulose had the smallest changes in drug content, viscosity, and pH among the formulations. Considering drug release, rheological properties, and stability, methylcellulose gel containing 1% drug as coprecipitates of PVP K90 was the best among the studied formulations, was promising for improving bioavailability of mefenamic acid and can be used in future studies.  相似文献   

11.
The objective of this study was to evaluate the potential of Carbopol® 71G-NF on the release of dextromethorphan hydrobromide (DM) from matrix tablets in comparison with hydroxypropyl methylcellulose (HPMC® K15M) and Eudragit® L100-55 polymers. Controlled release DM matrix tablets were prepared using Carbopol 71G-NF, HPMC K15M, and Eudragit L100-55 at different drug to polymer ratios by direct compression technique. The mechanical properties of the tablets as tested by crushing strength and friability tests were improved as the concentration of Carbopol, HPMC, and Eudragit increased. However, Carbopol-based tablets showed a significantly (P?<?0.05) higher crushing strength and a lower friability than HPMC and Eudragit tablets. No significant differences in weight uniformity and thickness values were observed between the different formulations. It was also found that Carbopol significantly (P?<?0.05) delayed the release of DM in comparison with HPMC K15M and Eudragit L100-55. A combination of HPMC K15M and Eudragit L100-55 in a 1:1 ratio at 20 and 30% significantly (P?<?0.05) delayed the release of DM than Eudragit L100-55 alone. Moreover, blends of Carbopol and HPMC at a 1:1 ratio at the 10, 20, and 30% total polymer concentration were investigated. The blend of Carbopol and HPMC at 10% level significantly (P?<?0.05) slowed the release of DM than Carbopol or HPMC alone, whereas blends at 20 and 30% level significantly (P?<?0.05) delayed the release of DM compared with HPMC or Carbopol alone. The results with these polymer blends showed that it was possible to reduce the total amount of polymers when used as a combination in formulation.  相似文献   

12.
Using mixture experimental design, the effect of carbomer (Carbopol® 971P NF) and hydroxypropylmethylcellulose (Methocel® K100M or Methocel® K4M) combination on the release profile and on the mechanism of drug liberation from matrix tablet was investigated. The numerical optimization procedure was also applied to establish and obtain formulation with desired drug release. The amount of TP released, release rate and mechanism varied with carbomer ratio in total matrix and HPMC viscosity. Increasing carbomer fractions led to a decrease in drug release. Anomalous diffusion was found in all matrices containing carbomer, while Case — II transport was predominant for tablet based on HPMC only. The predicted and obtained profiles for optimized formulations showed similarity. Those results indicate that Simplex Lattice Mixture experimental design and numerical optimization procedure can be applied during development to obtain sustained release matrix formulation with desired release profile.  相似文献   

13.
Abstract Poloxamer 407 copolymer (ethylene oxide and propylene oxide blocks) shows thermoreversible properties, which is of the utmost interest in optimising drug formulation (fluid state at room temperature facilitating administration and gel state above sol–gel transition temperature at body temperature promoting prolonged release of pharmacological agents). Pharmaceutical evaluation consists in determining the rheological behaviour (flow curve or oscillatory studies), sol–gel transition temperature, in vitro drug release using either synthetic or physiological membrane and (bio)adhesion characteristics. Poloxamer 407 formulations led to enhanced solubilisation of poorly water-soluble drugs and prolonged release profile for many galenic applications (e.g., oral, rectal, topical, ophthalmic, nasal and injectable preparations) but did not clearly show any relevant advantages when used alone. Combination with other excipients like Poloxamer 188 or mucoadhesive polymers promotes Poloxamer 407 action by optimising sol–gel transition temperature or increasing bioadhesive properties. Inclusion of liposomes or micro(nano)particles in Poloxamer 407 formulations offers interesting prospects, as well. Besides these promising data, Poloxamer 407 has been held responsible for lipidic profile alteration and possible renal toxicity, which compromises its development for parenteral applications. In addition, new findings have demonstrated immuno-modulation and cytotoxicity-promoting properties of Poloxamer 407 revealing significant pharmacological interest and, hence, human trials are in progress to specify these potential applications.  相似文献   

14.
Poloxamer 407 has excellent thermo-sensitive gelling properties. Nevertheless, these gels possess inadequate poor bioadhesiveness and high permeability to water, which limited its' application as a thermoresponsive matrix. The main aim of the present investigation was to develop thermosensitive and mucoadhesive rectal in situ gel of nimesulide (NM) by using mucoadhesive polymers such as sodium alginate (Alg-Na) and HPMC. These gels were prepared by addition of mucoadhesive polymers (0.5%) to the formulations of thermosensitive gelling solution containing poloxamer 407 (18%) and nimesulide (2.0%). Polyethylene glycol (PEG) was used to modify gelation temperature and drug release properties. The gelation temperature and drug release rate of the prepared in situ gels were evaluated. Gelation temperature was significantly increased with incorporation of nimesulide (2.0%) in the poloxamer solution, while the addition of the mucoadhesive polymers played a reverse role on gelation temperature. The addition of PEG polymers increased the gelation temperature and the drug release rate. Among the formulations examined, the poloxamer 407/nimesulide/sodium alginate/PEG 4000 (18/2.0/0.5/1.2%) exhibited the appropriate gelation temperature, acceptable drug release rate and rectal retention at the administration site. Furthermore, the micrographic results showed that in situ gel, given at the dose of 20mg/kg, was safe for no mucosa irritation. In addition, it resulted in significantly higher initial serum concentrations, C(max) and AUC of NM compared to the solid suppository.  相似文献   

15.
Thermal gelation of Poloxamer 407 lidocaine hydrochloride gels was characterized by rheological studies. Lidocaine, a local anesthetic used for treatment of acute and chronic pain, presents short duration action; thus a long-action single-dose injection would be of clinical importance. Poloxamer 407 gel can extend the release and the action of lidocaine. In the present work, aqueous gels with lidocaine containing different concentrations of Poloxamer 407 and additives like inorganic salts (NaCl, NaH(2)PO(4), Na(2)CO(3)) and PEG 400 were obtained. Viscosity measurements and the optimal sol-gel transition temperature were obtained by these rheological studies. Poloxamer 407 gels are viscoelastic materials because they have elastic modulus (G'), characteristic of solid materials, and viscous modulus (G"), characteristic of liquid materials. Poloxamer 407 gels are pseudoplastic; therefore, when shear deformed, their viscosity decreases. Increase of the polymer concentration increases the viscosity of the gels, which can change the releasing process of lidocaine from the gel. The sol-gel transition temperature was decreased by increasing the polymer concentration and by the presence of additives. The rheological behaviour of Poloxamer gels characterized in this work can be useful for understanding further studies of drug release.  相似文献   

16.
The matrix type transdermal drug delivery systems (patches) of Nitrendipine were prepared by film casting technique. The patches were characterized for physical, in vitro release studies and ex-vivo permeation studies (human cadaver skin). On the basis of in vitro drug release and skin permeation performance, formulation B3 was found to be better than the other formulations and it was selected as the optimized formulation. The final optimized formulation (B3) was subjected to skin irritation, pharmacokinetic, pharmacodynamic and stability studies. The maximum percentage drug release in 48 hours was 94.67 ± 3.25 for B3 and 91.43 ± 2.106 for A2 formulation. Again formulation B3 (0.0627 mg/cm2/h) and A2 (0.0566 mg/cm2/h) showed maximum skin flux in the respective series. Patches prepared with Plasdone S-630 were more flexible as compared to PVP K 30 containing patches. Patches prepared with PVP K 30 showed drug release and skin permeation at higher percentage as compared to those containing Plasdone S-630. The interaction studies carried out by comparing the results of ultraviolet, infrared, TLC and DSC analyses for the pure drug, medicated and placebo formulations indicated no chemical interaction between the drug and excipients. The TDDS was found to be free of any skin irritation as suggested by skin irritation score of 1.16 (< 2.00) under Draize score test.  相似文献   

17.
A thermosensitive micelles–hydrogel hybrid system based on Poloxamer 407 (P407) was prepared to resolve the fast erosion and low loading capability of lipophilic drug of P407 gels for local chemotherapy. Different amounts of glutaraldehyde (GA) were applied to generate cross-linked networks with carboxymethyl chitosan (CMCS) interpenetrated in P407 gels, in which paclitaxel (PTX)-loaded N-octyl-O-sulfate chitosan micelles (PTX-M) were dispersed uniformly. The in vitro characteristics of CMCS-modified P407 gels (PTX-M-MG) were performed by examining the viscosity, swelling ratio, mechanical property, and drug release, while the in vivo evaluation included tissue distribution and anticancer efficacy through in-tratumoral administration in hepatoma solidity cell (Heps) tumor-bearing mice. The results showed that PTX-M-MG containing 0.05% (w/v) GA possessed lower viscosity, higher swelling ratio, stronger mechanical property, and longer term drug release, in which the loading efficiency of PTX was enlarged by the introduction of PTX-M. Moreover, PTX-M-MG revealed a prolonged retention at tumor sites, lasting for 20 days, and a superior tumor inhibition rate (64.27%) with reduced toxicity compared with Taxol®, PTX-M, and PTX-M loaded unmodified P407 gels (PTX-M-P407). It can be concluded that PTX-M-MG is a promising local delivery system for hydrophobic drug in cancer therapy, providing both improved efficacy and relieved side effects. © 2013 Wiley Periodicals, Inc. and the American Pharmacists Association J Pharm Sci 102:2707–2717, 2013  相似文献   

18.
The objective of this work was to assess the effect of two formulation variables, hydroxypropylmethylcellulose (HPMC)/lactose ratio and HPMC viscosity grade, on the release of a model drug and HPMC, as well as the mechanism of drug release from HPMC-based matrix tablets. A water-soluble compound, adinazolam mesylate, was used as the model drug. Both drug and HPMC release were found to be a function of the formulation variables, with higher drug and HPMC release rates for formulations with lower HPMC/lactose ratios and lower HPMC viscosity grades. However, the K15M and K100M formulations had identical drug release profiles. All the drug release data fit well to the Higuchi expression. By comparing the drug and HPMC release data, it was concluded that diffusion of drug through the hydrated gel layer was the predominant drug release mechanism for most of the formulations studied.  相似文献   

19.
The present work was aimed at designing microsponge based colon specific drug delivery system containing paracetamol. Eudragit S-100 based microsponges containing drug in varying amounts were prepared using quasi-emulsion solvent diffusion method. The microsponges were prepared by optimizing various process parameters. DSC and FTIR studies indicated compatibility of the drug in various formulations. Shape and surface morphology of the microsponges were examined using scanning electron microscopy. The formulations were subjected to in vitro release studies and the results were evaluated kinetically and statistically. The in vitro release data showed a bi-phasic pattern with an initial burst effect. In the first hour drug release from microsponges was found to be between 18-30%. The cumulative percent release at the end of 12(th) hour was noted to be between 74-98%. The release kinetics showed that the data followed Higuchi model and the main mechanism of drug release was diffusion. The colon specific tablets were prepared by compressing the microsponges followed by coating with pectin: hydroxypropylmethyl cellulose (HPMC) mixture. In vitro release studies exhibited that compression coated colon specific tablet formulations started releasing the drug at 6(th) hour corresponding to the arrival time at proximal colon. The study presents a new approach for colon specific drug delivery.  相似文献   

20.
Thermoreversible gel of meloxicam, efficient for the treatment of joint diseases, was aimed to prepare for night application available for chronotherapy in this study. Poloxamer 407 and 188 polymers were used at 20-30% w/w as a vehicle in combination with different additives (polyvinylmethylether maleic anhydride copolymer, hydroxypropyl methylcellulose, polyethylene glycol 400, dimethyl sulfoxide, sodium chloride). Characterisation of prepared gels was evaluated by viscosity and texture analysis, and the effect of formulation variables on the gel formulations were evaluated by in vitro drug release and erosion studies. Between the investigated gel bases, Poloxamer 407-hydroxypropyl methylcellulose gel was found to be ideal due to its gel strength (1.560±0.0135 N), viscosity (312.3±2.06 cP) and release characteristics. These promising results could be encouraging for further studies to make it an alternative to commercial dosage forms.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号