Curcumin solid dispersion based on three model acrylic polymers: formulation and release properties

Abstract To investigate structure-property relationship of polymer-based curcumin solid dispersion (SD), three acrylic polymers were used to formulate curcumin SD by solvent evaporation method. Curcumin Eudragit EPO SD (cur@EPO), curcumin Eudragit RS PO SD (cur@RSPO) and curcumin Eudragit RL PO SD (cur@RLPO) showed deep red, golden orange and reddish orange color, respectively. Cur@RSPO entrapped 15.42 wt% of curcumin followed by cur@RL PO and cur@EPO. FTIR spectra indicated that in cur@EPO, curcumin may transfer hydrogen to the dimethylaminoethyl methacrylate group and thus change its color to red. In contrast, curcumin may form hydrogen bonding with Eudragit RS PO and Eudragit RL. Curcumin exists in amorphous state in three SDs as proved by differential scanning calorimetry and X-Ray diffraction measurement. In vitro digestion presented that lower pH value in simulated gastric fluid (SGF) stimulates the curcumin release from cur@EPO while permeability influences the release profile in other two SDs. When in simulated intestinal fluid (SIF), first order release model governs the release behaviors of all three SDs which showed sustained release pattern. Our results are helpful to elucidate how structure of polymer may impact on the major properties of curcumin contained SD and will be promising to broaden its therapeutic applications.

Development and optimization of metoclopramide containing polymeric patches: impact of permeation enhancers

Abstract The study is aimed to develop a monolithic controlled matrix transdermal patches containing Metoclopramide as a model drug by solvent casting method. Eudragit L100, Polyvinylpyrrolidone K-30, and Methylcellulose were used in different ratios and Polyethylene glycol 400 added as a plasticizer. Resulting patches were evaluated for their physicochemical characters like organoleptic characters, weight variation, folding endurance, thickness, swelling index, flatness, drug content, swelling index, percentage erosion, moisture content, water vapor transmission rate and moisture uptake. Formed patches were also evaluated through Fourier transform spectroscopy (FT-IR), X-ray diffraction (XRD), Differential Scanning calorimetry (DSC) and Scanning Electron Microscopy (SEM). Results of SEM unveiled smooth surface of drug-loaded patches. In-vitro dissolution studies were conducted by using dissolution medium phosphate buffer saline pH 7.4. Effect of natural permeation enhancers was elucidated on two optimized formulations (Z4 and Z9). Different concentrations (5%-10 %) of permeation enhancers i.e. Olive oil, Castor oil and Eucalyptus oil were evaluated on Franz diffusion cell using excised abdominal rat skin. Z4-O2 (Olive oil 10%) had enhanced sustain effect and flux value (310.72) close to the desired flux value. Z4-O2 followed Higuchi release model (R2= 0.9833) with non-fickian diffusion release mechanism (n=0.612)

Fabrication of potential gastroretentive microspheres of itraconazole for stomach-specific delivery: Statistical optimization and in vitro evaluation

The premise of the study was to develop and optimize multiple unit gastroretentive microspheres of itraconazoleto prolong its localization in the stomach and analyzed using response surface methodology. The emulsion solventdiffusion evaporation method was used to prepare hollow microsphere of ethyl cellulose and Eudragit RS100 as lowdensity shell-forming polymers. The experimental design matrix was prepared using a central composite design tostudy the effect of various process parameters over response variables. The optimized microspheres showed a particlesize of 285.1µm, drug entrapment efficiency of 86.8%, buoyancy of 51.1%, and cumulative drug release of 77.80%.The experimental responses were in good harmony with the predicted values. The compatibility between drug andexcipients was determined by Fourier-transform infrared and differential scanning calorimetry analysis. The resultssignify that gastroretentive hollow microspheres are a promising vehicle to extend the retention time of itraconazolein the upper GI tract, and it can be floated in an acidic medium for a prolonged period.

Formulation And Evaluation Of Metformin Hydrochloride Loaded Floating Microspheres

Objective: The main objective of this study was to develop and evaluate the eudragit and HPMC coated metformin hydrochloride floating microspheres, in which HPMC helps in floating and eudragit as a coating material for a site-specific drug release in a controlled manner and the active moiety metformin used as anti-hyperglycemic agent. Methods: The floating microsphere was prepared by the solvent evaporation method incorporating metformin as a model drug. The prepared floating microsphere were characterized for particle size, %yield, drug loading and entrapment efficiency, compatibility study, %buoyancy, surface morphology and In vitro drug release and release kinetics. Results: The result metformin loaded floating microsphere was successfully prepared and the particle size range from 397±23.22 to 595±15.82 µm, the entrapment efficiency range from 83.49±1.33 to 60.02±1.65% and drug loading capacity range from 14.3±0.54 to 13.31±0.47% and %buoyancy range from 85.67±0.58 to 80.67±1.15%. The FT-IR and X-RD analysis confirmed that no any interaction between drug and excipient, and surface morphology confirmed those particles are sphere. The floating microsphere show maximum 96% drug release in pH 0.1N HCL and follow the Korsmeyer peppas model of the super case-2 transport mechanism. Conclusion: These results suggest that metformin loaded floating microspheres could be retain in stomach for long time and give site specific drug release in controlled manner.

Screening of Ketoprofen-Poloxamer and Ketoprofen-Eudragit solid dispersions for improved physicochemical characteristics and dissolution profile

The aim of the present study was to enhance the dissolution rate of an NSAID drug Ketoprofen by formulating it into solid dispersions with water soluble carrier Poloxamer 188 and Eudragit S 100. The solid dispersions of Ketoprofen with Poloxamer 188 were prepared at 1:1, 1:1.5 and 1:2 (Ketoprofen: Poloxamer 188) ratio by Solvent evaporation methods. The same concentration ratio was used for the preparation of solid dispersion with Eudragit S 100 by melting/fusion technique. Further, solid dispersions were investigated by solubility, ATR-FTIR, XRD, DSC, surface morphology, in-vitro dissolution and accelerated stability study. Results demonstrated that both Poloxamer 188 and Eudragit S 100 improve solubility of drugs by 8­10 folds. The result of ATR-FTIR study showed the slight shifting/broadening of principle peaks. In vitro dissolution studies showed that in the solid dispersion system containing Ketoprofen: Poloxamer 188 batch P2 (1:1.5) gives faster dissolution rate of Ketoprofen than the physical mixtures. The solid dispersion with Eudragit S 100, batch E1 (1:1) gives faster dissolution rate of Ketoprofen than the physical mixtures. In phase solubility study with Poloxamer 188 showed concentration dependent solubilization of drug but Eudragit S 100 produced opposite result. The effect of pH on solubility of Eudragit S 100 was carried out which showed solubility at pH 7.4. The dissolution profile of solid dispersion with Eudragit S 100 at pH 7.4 gives excellent result. The Accelerated stability of solid dispersions & its physical mixtures were studied at 400±2 °C/75 ± 5% RH for a period of 1 month. In these studies, Solid Dispersion batches produced an unstable formulation. The Ketoprofen solid dispersions with Poloxamer 188 and Eudragit S 100 could be introduced as a suitable form with improved solubility

Development of controlled release dexketoprofen tablets and prediction of drug release using Artificial Neural Network (ANN) modelling

Dexketoprofen trometamol (DT) is an active S (+) enantiomer of ketoprofen, and a non-steroidal anti-inflammatory agent. DT has a short biological half-life and the dosing interval is quite short when there is a need to maintain the desirable effect for longer time periods. Consequently, a controlled release DT tablet was designed for oral administration aiming to minimize the number of doses and the possible side effects. Calculations of the parameters for controlled release DT tablets were shown clearly. Controlled release matrix-type tablet formulations were prepared using hydroxypropyl methylcellulose (HPMC) (low and high viscosity), Eudragit RS and Carbopol, and the effects of different polymers on DT release from the tablet formulations were investigated. The dissolution rate profiles were compared and analyzed kinetically. An Artificial Neural Network (ANN) model was developed to predict drug release and a successful model was obtained. Subsequently, an optimum formulation was selected and evaluated in terms of its analgesic and anti-inflammatory activity. Although the developed controlled release tablets did not have an initial dose, they were found to be as effective as commercially available tablets on the market. Dissolution and in vivo studies have shown that the prepared tablets were able to release DT for longer time periods, making the tablets more effective, convenient and more tolerable.

Análisis por FTIR y DSC de complejos polielectrolito entre Eudragit® E100 y ácido benzoico como evidencia de hidrólisis de los grupos éster del polímero / FTIR and DSC analysis of polyelectrolyte complexes between Eudragit® E100 and benzoic acid as evidence of hydrolysis of the polymer ester groups

RESUMEN La obtención de complejos polielectrolito entre el polímero catiónico Eudragit® E100 y moléculas aniónicas, con neutralización adicional de un ácido inorgánico, ha sido una práctica recurrente en el área de investigación de estos sistemas de liberación controlada. En el presente trabajo se buscó estudiar el efecto de la adición del ácido fuerte en el polímero, para ello se llevó a cabo la obtención por evaporación de solvente de diez complejos (de diferente composición entre Eudragit® E100 y ácido benzoico o ácido clorhídrico) y de cuatro ionómeros (sin el activo), a los cuales se les realizó análisis por FTIR y DSC. Los resultados demostraron la obtención de los respectivos complejos polielectro-lito y de los ionómeros; además los espectros de FTIR revelaron la relación directa entre la reacción de hidrólisis de los grupos ésteres del polímero y la proporción de HCl adicionada. Los termogramas, por su parte, evidenciaron la existencia de una reacción en el polielectrolito (PE), la cual se favoreció en aquellas composiciones en las que el proceso de hidrólisis ocurrió en mayor magnitud. El proceso de hidrólisis que se describe en el presente estudio debe tenerse en consideración en las futuras investigaciones en el campo, ya que su ocurrencia podría tener implicaciones en las diversas variables que se evalúan en este tipo de sistemas.

SUMMARY Polyelectrolyte complexes obtention between Eudragit® E100 (cationic polymer) and anionic molecules with additional neutralization of inorganic acids is a common practice in the development of these systems. In the present work the addition of strong acid effect on polymer structure was evaluated through FTIR and DSC analysis of a set of ten complexes with different composition (between Eudragit® E100 and benzoic acid) and four ionomers (without the preservative) obtained by solvent evaporation technique. Results demonstrated the complexes and ionomers formation. FTIR spectra revealed direct relationship between polymer ester groups hydrolysis reaction and the amount of HCl added. The thermograms, on the other hand, evidenced the existence of a reaction in the polyelectrolyte, which was favored in those compositions with more hydrolysis process. The degradation reaction described in this study should be taken into consideration in future research, since its occurrence could have implications in variables evaluated in this type of systems.

Formulation And Evaluation Of Benazepril Hydrochloride Transdermal Films For Controlled Drug Release

The current research deals with formulation and evaluation of Benazepril hydrochloride transdermal films, by varying ratios of polymers Eudragit RL100, Eudragit RS100 by film casting technique. Preformulation studies were conducted to check the solubility, melting point and partition coefficient. The eleven formulations were analyzed for physicochemical parameters and drug dissolution potential of transdermal films. All the formulations are transparent with minimum weight variation and uniform thickness. The drug content uniformity of all the formulations vary between 96.84 ± 3.7% to 96.98 ± 1.6% indicate uniform drug distribution. The low water vapour transmission values indicate good water vapour permeation. The folding endurance is between 246 ± 4.60 to 315 ± 4.13 indicates that the transdermal films can withstand rupture. In vitro drug dissolution study indicates maximum amount of drug 96.8% (F2) released in 24 h when compared with marketed formulation 84.81%. The release order follows Fickian diffusion. The formulation F2 was optimized based on drug flux, permeability coefficient and enhancement ratio.

Development and evaluation of liquid oral controlled release systems for Losartan potassium

Losartan potassium is a water soluble antihypertensive agent with short half-life. Controlling its release will improvepatient compliance. The benefit will be extended for geriatric patients if the developed system was liquid. The objectiveof this work was to develop controlled release oral liquid losartan potassium. This employed a combination of in situgelation and coating drug particles with pH-dependent polymer (Eudragit® L100). Solid dispersion (SD) prepared at1:1, 1:1.5, and 1:2 drug : polymer ratios, respectively. Sodium alginate solution was loaded with either pure drug orSD, in presence and absence of 1% w/v chitosan. These systems were evaluated for the drug release using continuouspH variation study. Alginate formulation with pure drug underwent in situ gelation in the gastric conditions but lost thegelling strength in the intestinal phase with burst drug release. Loading the formulation with SD resulted in controlleddrug release both in the gastric and intestinal phases. Increasing eudragit concentration in SD decreased the drugreleased with total release efficiency of 62.1%, 53.0%, and 41.7%. Incorporation of chitosan at reduced further drugrelease rate reaching 21% at the higher eudragit concentration. The study provided the formulator with a range of oralliquid formulations for controlled release of losartan potassium.

Characterization of Eudragit types and Kollidon SR inter-polymer complexes and their effects on the drug release

A novel of polymer combination promotes an increase of the ability for controlling the drug release. The objectiveof this research was to characterize the inter-polymer complexes (IPCs) of Eudragit (Eud) types (Eud RS, Eud L, orEud E) and Kollidon SR (KSR), and elucidate their effects on the drug release kinetics and mechanism. Differentpreparation techniques were proposed using spray drying and ultrasonic-assisted anti-solvent techniques. The thermalactivity, e.g., glass transition temperature (Tg) and Fourier transform infrared spectroscopy were used to characterizethe molecular interaction of these IPCs. Theophylline (THP) was selected as a drug model. The effect on the drugrelease kinetics and mechanism was the main concern of this study. Depending on the results, the hydrogen bondingformation between polymers was observed by a shifting of OH and carbonyl group vibrations. In addition, the van derWaals interaction was identified by an alteration in the vibrational band around the 1,000–1,500 cm−1. Meanwhile, thechange of physicochemical characteristic was identified by the Tg of IPCs. Eud E-KSR and Eud E-Eud L IPC wereunable to control the THP release. Meanwhile, Eud L-KSR IPC and Eud RS-KSR IPC were success to control theTHP release, but it was pH dependent and independent, respectively. This study concluded that the IPCs allowed theTHP release in a controlled manner based on the IPC characteristics and their interactions. Either positive or negativeinteractions on the drug release were observed due to native characteristics of polymers.

Formulation Optimization of Rutaecarpine Transdermal Patch / 中国药学杂志

OBJECTIVE: To screen pressure sensitive adhesive system and penetration enhancer of rutaecarpine transdermal patch. METHODS: The patch was prepared by solvent evaporation method. The ratio between pressure sensitive adhesive (Eudragit E100), crosslinking agent (succinic acid) and plasticizer (dibutyl sebacate) of the rutaecarpine patch were screened through Box-Behnken design by using adhesion (stick power, shear strength, peel force) as the index. The ratio between pressure sensitive adhesives and chemical enhancers (azone and oleic acid) were screened by adhesion and permeation experiments in vitro using custom design, which were carried out by using improved Franz diffusion cells through excised mice skin. RESULTS: The optimized formulation of rutaecarpine transdermal patch consisted of 83% pressure sensitive adhesives (63.5% Eudragit E100, 5.5% succinic acid, 14% dibutyl sebacate), 10% azone, 6.4% oleic acid and 0.6% rutaecarpine. The stick power, shear strength, and peel force of the patch were 15 steel balls, (10.97 ± 0.32) h and (0.16 ± 0.02) kN•M-1, respectively. The cumulative permeation amount and permeation rate of the patch were (29.71 ± 1.19) μg•cm-2 and (1.36 ± 0.10) μg•cm -2•h -1, respectively. CONCLUSION: The optimized rutaecarpine patch show increased permeation and appropriate adhesion. This study provides the basis for future research.

Influence of different formulation variables on the performance of transdermal drug delivery system containing tizanidine hydrochloride: in vitro and ex vivo evaluations

The present study was aimed at preparation of transdermal patches of tizanidine HCl, evaluation of the effect of polymers on in vitro release pattern of the drug, and the effect of permeation enhancers on the penetration of the drug through the rabbit skin. Various proportions of hydrophilic (HPMC) and hydrophobic (Eudragit L-100) polymers were used with PEG 400 as film-forming agent, and Span 20 or DMSO as permeation enhancer. The formulations were assessed for physicochemical characteristics and in vitro drug release studies using USP paddle over disc method in phosphate buffered saline (pH 7.4) at 32.0±1°C. On the basis of in vitro studies and physicochemical evaluations, S03-A and S04-A were selected at Eudragit : HPMC ratios of 8 : 2 and 7 : 3, respectively, for further ex vivo analysis. The effects of different concentrations of Span 20 and DMSO were evaluated on excised rabbit skin using Franz diffusion cell. Cumulative drug permeation, flux, permeability coefficient, target flux, and enhancement ratio were calculated and compared with the control formulations. Kinetic models and Tukey's multiple comparison test were applied to evaluate the drug release patterns. Formulation SB03-PE containing Eudragit L-100:HPMC (7:3) with Span 20 (15% w/w) produced the highest enhancement in drug permeation, and followed zero order kinetic model with super case-II drug release mechanism.

Formulation development and evaluation of colon targeted delayed release methotrexate pellets for the treatment of colonic carcinoma

Colonic carcinoma is one of the most common internal malignancies and is the second leading cause of deaths in United States. Methotrexate (MTX) is a drug of choice in the treatment of colon cancer. The aim of the present research work was to develop and characterize colon targeted pellets of MTX for treatment of colonic carcinoma. The product and process parameters were optimized by screening methods. Pellets were prepared by extrusion spheronization using microcrystalline cellulose (MCC) as spheronizing aid and ethyl cellulose (EC) as release retardant in different ratio. Based on the physical appearance, sphericity and % in vitro drug release, batch P17 containing EC: MCC (3:7) was optimized for core pellets. The site specificity was obtained by screening the coating polymers and by coating the core pellets with EudragitS100. The 32 full factorial design was applied in which airflow rate (X1) and coating time (X2) were the independent parameters and physical appearance (Y1) and time taken for 100% drug release (Y2) were selected as the dependent variables. From the results obtained, 6min of coating time and 60cm3/min airflow rate was optimized. The batch B5 showed appropriate physical appearance and % in vitro drug release upto 17hr indicating sustained release property. The ex-vivo studies performed on rat colon indicated a significant relation with the in vitro drug release. The drug release followed Higuchi's model indicating the diffusion pattern of drug release from the matrix of pellets. Thus, the coated pellets can be a good candidate for site specific delivery of MTX to colon by decreasing the gastric irritation and thus to improve bioavailability.

Development and characterization of pullulan-polymethacrylate free films as potential material for enteric drug release

ABSTRACT Free films of pullulan-polymethacrylate associations were produced by casting process to develop a novel target-specific material. For characterization, tests of water vapor permeability, swelling index, infrared absorption spectroscopy, thermogravimetric analysis, scanning electron microscopy and mechanical analysis were performed. The polysaccharide concentration directly influenced vapor permeability and swelling, increasing the values of the latter up to five times when added in a proportion of 20% (per weight). The individual properties of each polymer were maintained, and chemical interactions were not detected. The films were found to be thermally stable and they had unaltered mechanical properties with the addition of the polysaccharide. The microscopic analysis revealed rugosity that was proportional to pullulan and disorganization of the polymer network at pH 6.8. These results suggest that this novel material has potential for enteric drug release because of synergism between pH and enzyme dependence.

Eudragit ® FS 30 D polymeric films containing chondroitin sulfate as candidates for use in coating seeking modified delivery of drugs

ABSTRACT Polymeric films associating different concentrations of Eudragit(r) FS 30 D (EFS) and chondroitin sulfate (CS) were produced by casting for the development of a new target-specific site material. Formed films kept a final polymer mass of 4% (w/v) in the following proportions: EFS 100:00 CS (control), EFS 95:05 CS, EFS 90:10 CS and EFS 80:20 CS. They were analyzed for physical and chemical characteristics using Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and Raman spectroscopy. Furthermore, they were characterized by their water vapor permeability and degree of hydration at different conditions simulating the gastrointestinal tract. No chemical interactions were observed between CS and EFS, suggesting only a physical interaction between them in the different combinations tested. The results suggest that EFS and CS, when combined, may form films that are candidates for coating processes seeking a modified drug delivery, especially due to the synergism between pH dependency and specific biodegradability properties by the colonic microbiota. EFS 90:10 CS proved to be the most suitable for this purpose considering hydration and permeability characteristics of different associations analyzed.

Preparation of Dexibuprofen Sustained-release Pellets and Analysis on Drug Release Behavior / 中国药房

OBJECTIVE:To prepare dexibuprofen sustained-release pellets,and to analyze the drug release behavior in vitro. METHODS:Centrifugal granulation powder layering-eudragit dispersion coating method was used to prepare dexibuprofen sus-tained-release pellets using 3%HPMC as adhesive agent. The formula of the pellets was optimized by orthogonal test with weight ra-tio of sucrose to dexibuprofen,weight ratio of HPMC to Eudragit NE30D and coating weight as factors,using 1,4 and 10 h accu-mulated release rate (Q) as index. The release of the drug from the pellets was analyzed. RESULTS:The optimized formulation was that the proportion of sucrose to drug was 1:10,the weight ratio of HPMC to Eudragit NE30D was 1.5:1,the increased weight of coating material was 8%. Q1 h,Q4 h and Q10 h of prepared pellets were 21%,57% and 89%,respectively(n=3). The co-rrelation coefficient of zero-order,one-order and Higuchi equation release model were 0.956 6,0.989 9,0.996 5. CONCLUSIONS:Prepared pellets show good sustained-release effect in vitro. Drug release of pellets is more in accordance with Higuchi equation.

Microencapsulation of a Colombian Spodoptera frugiperda Nucleopolyhedrovirus with Eudragit® S100 by spray drying

A Colombian Spodoptera frugiperda nucleopolyhedrovirus NPV003 with high potential for the development of an efficient biopesticide was microencapsulated by spray drying with a pH dependent polymer (Eudragit® S100). Conditions for microparticles production were standardized and microencapsulation process was validated. Physical properties, insecticide activity and photo-stability of microencapsulated virus were determined. The microparticles were spherical and irregular shaped, with sizes between 17.64 and 19.47 µm. Moisture content was 10.38 ± 0.87%; encapsulation efficiency 84.61± 13.09% and process yield was 91.20 ± 6.40%. Microencapsulation process did not affect viral insecticidal activity and provided efficient protection against UVB radiation. Results demonstrated technological feasibility of spray drying process to be used in formulating a biopesticide based on NPV003.

Nonaqueous Enteric Coating Application of HPMC and Eudragit L100 on Hard Gelatin Capsules: Designed to Achieve Intestinal Delivery.

Omeprazole (OMZ) is a weak base proton pump inhibitor and it can be easily broken down in the acidic location before reaching to the small intestine where it is absorbed. Therefore, the main aim of this investigation is to protect the drug in the stomach environment with the object of exhibiting 100% drug release at the site of absorption. Prior to coating all the capsules were filled with API and other suitable excipients then placed on to the lab model conventional coating pan. Two different polymers such as (HPMC) and Eudragit L 100 were selected for this study. First, the pre coating solution (HPMC) was employed after drying enteric coating solution (Eudragit L 100) was applied under suitable coating parameter finally over coating solution of (HPMC) was applied and kept for drying. Different coating thickness ranges from 38.33 to 89.75% was observed by Scanning electron microscopy and tested for acid uptake test, disintegration and dissolution tests in pH 1.2 HCl media for 2 hours and pH 6.8 phosphate buffer solution. Less coating thickness capsules were allowed to penetrate the acid and the capsules were ruptured in an acid environment, therefore early drug release was occurred in acid media. Whereas capsules with high coating thickness of 89μm were not allowed acid to penetrate this indicates that the drug could be protected from degradation in the gastric environment.

Formulation and Evaluation of Ketoconazole Polymeric Films for Topical Application.

The objective of the current paper was to prepare and evaluate various polymeric films for fungal infection treatment and its impact on volunteer patients. Different Eudragit polymeric films containing Ketoconazole as antifungal drug were prepared by solvent casting technique. The prepared films were tested for their physicomechanical properties as tensile strength, physical endurance, elasticity, water vapor permeation and water loss. The release of ketoconazole from the prepared medicated films was examined. It is involved 20 volunteers suffering from legs fungal infection. Ten of the patients used the films and a follow up study was carried out for 14 days, in comparison with other patients who applied ketoconazole medicated ointment, cream gel and Emulgel. The results revealed that films prepared with Eudragit RL 100 containing glyceryl triacetate produced maximum release of ketoconazole both In vitro and In vivo as compared with other topical dosage forms as ointment, cream, gel and Emulgel. Moreover, the films constitute a simple and convenient method for treatment of various fungal infections. As conclusion, the use of antifungal drugs such as Ketoconazole incorporated in polymeric films, the output results provided promised evidence in the treatment of dermatophytosis.

Optimization of pramipexole hydrochloride sustained-release tablets using Box-Behnken design and mechanism of in vitro drug release / 中国药科大学学报

@#The formulations of pramipexole hydrochloride sustained-release tablets were screened by single factor test and optimized by Box-Behnken design. The effects of the viscosity and content of hydroxypropyl methyl cellulose, as well as the insoluble sustained-release material combined with HPMC K100M on the in vitro release behavior were investigated. After single factor screening, a three-factor, three-level Box-Behnken design was used for optimization using the contents of HPMC K100, Eudragit RSPO and Eudragit L100 as independent variables, and the cumulative release at different time as responses. The optimal range of the three-factor optimized by Box-Behnken design, one of the optimized formulations was achieved with HPMC K100M of 101. 5 mg, Eudragit RSPO of 98 mg, and Eudragit L100 of 13. 7 mg, and the observed responses of the optimized formulation were very close to the predicted values. The in vitro drug release mechanism of the tablet was studied by drug released model fitted with different equations. The results explained that Eudragit RSPO promoted the release of the pramipexole hydrochloride, while Eudragit L100 blocked the release, and there was an antagonism between them. In conclusion, the drug release behavior of optimized formulations prepared by Eudragit RSPO/L100 was stable, less pH-dependent, which improved the drug bioavailability in vivo.