Controlled Release of Trimaterene from Poly(DL-Lactide-Co-Glycolide) Microspheres

1993 ◽  
Vol 331 ◽  
Author(s):  
Amy D. Ouellete ◽  
Nicholas A. Peppas
Keyword(s):  
Controlled Release ◽  
Drug Loading ◽  
Release Behavior ◽  
Release Rates ◽  
Diffusion Controlled ◽  
Order Of Magnitude ◽  
Lower Drug ◽  
Biphasic Release ◽  
Silicone Matrix

AbstractRelease of triamterene from 150–300 gm poly(DL-lactide-co-glycolide) (PLGA) microspheres was investigated in vitro as a function of lactic acid/glycolic acid (LA/GA) copolymer ratio and drug loading both with free microspheres and with microspheres embedded in a silicone matrix. Biphasic release consisting of diffusion controlled release followed by erosion controlled release corresponding to polymer degradation was observed in all samples. Drug release from PLGA 50:50 copolymer microspheres was three times faster than the release from PLGA 75:25 microspheres for the higher drug loading (20 wt%) and slightly faster for the lower drug loading (10 wt%). Release rates from spheres containing the higher drug loading were approximately one order of magnitude faster than release from spheres containing the lower drug loading for the same PLGA copolymer. The same qualitative results were observed for the spheres embedded in silicone matrices; however, the overall release was much slower. The results demonstrate that release behavior may be altered by changing LA/GA copolymer ratio, drug loading, and microsphere environment to obtain the desired release characteristics.

The preparation, drug loading and in vitro NIR photothermal-controlled release behavior of raspberry-like hollow polypyrrole microspheres

2015 ◽  
Vol 3 (47) ◽  
pp. 9186-9193 ◽  
Author(s):  
Jie Wang ◽  
Fuxing Lin ◽  
Jinxing Chen ◽  
Mozhen Wang ◽  
Xuewu Ge
Keyword(s):  
Controlled Release ◽  
Cancer Therapy ◽  
Drug Loading ◽  
Release Behavior ◽  
Templating Method ◽  
Therapy Effect

Raspberry-like hollow polypyrrole microspheres (H-PPy), which are prepared through a templating method, exhibit promising synergistic cancer therapy effect.

scholarly journals PREPARATION, CHARACTERISATION AND EVALUATION OF ROPINIROLE HYDROCHLORIDE LOADED CONTROLLED RELEASE MICROSPHERES USING SOLVENT EVAPORATION TECHNIQUE

2018 ◽  
Vol 10 (6) ◽  
pp. 57
Author(s):  
Koyel Kar ◽  
R. N. Pal ◽  
N. N. Bala
Keyword(s):  
Controlled Release ◽  
Drug Release ◽  
Release Kinetics ◽  
Drug Loading ◽  
Solvent Evaporation ◽  
In Vitro Drug Release ◽  
Aqueous Solvent ◽  
Evaporation Technique ◽  
Ropinirole Hydrochloride

Objective: The major objective of the research work was to design, characterise and evaluate controlled release microspheres of ropinirole hydrochloride by using non-aqueous solvent evaporation technique to facilitate the delivery of the drug at a predetermined rate for a specific period of time.Methods: Ropinirole hydrochloride microspheres were prepared by using different low-density polymers such as eudragit RL 100, eudragit RS 100 and ethylcellulose either alone or in combination with the help of non-aqueous solvent evaporation technique. All the formulated microparticles were subjected to various evaluation parameters such as particle size analysis, micrometric properties, drug entrapment efficiency, percentage drug loading, percentage yield and in vitro drug release study. The compatibility of the drug and polymers was confirmed by physical compatibility study, fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC) and x-ray diffraction study (XRD). The formation of the most optimized batch of the microsphere (F12) was confirmed by scanning electron microscopy (SEM), DSC, FTIR, and XRD. In vitro drug release study and in vitro drug release kinetics study of the formulated microspheres were also carried out.Results: Drug-polymer compatibility studies performed with the help of FTIR and DSC indicated that there were no interactions. Results revealed that non-aqueous solvent evaporation technique was a suitable technique for the preparation of microspheres as most of the formulations were discrete, free-flowing and spherical in shape with a good yield of 55.67% to 80.09%, percentage drug loading of 35.52% to 94.50% and percentage drug entrapment efficiency of 36.24% to 95.07%. Different drug-polymer ratios, as well as the combination of polymers, played a significant role in the variation of over-all characteristics of formulations. Based on the data of various evaluation parameters such as particle size analysis, percentage drug loading, percentage drug entrapment, percentage yield, rheological studies and in vitro drug release characteristics, formulation F12 was found to fulfil the criteria of ideal controlled release drug delivery system. F12 showed controlled release till the 14th hour (97.99%) and its in vitro release kinetics was best explained by zero-order kinetics and followed Korsemeyer-Pappas model (Non-Fickian mechanism). SEM of F12 revealed the formation of spherical structures. The FTIR study of F12 confirmed the stable nature of ropinirole in the drug-loaded microspheres. DSC and XRD patterns showed that ropinirole hydrochloride was dispersed at the molecular level in the polymer matrix.Conclusion: The controlled release microparticles were successfully prepared and from this study, it was concluded that the developed microspheres of ropinirole hydrochloride can be used for controlled drug release to improve the bioavailability and patient compliance and to maintain a constant drug level in the blood target tissue by releasing the drug in zero order pattern.

Preparation and in vitro controlled release behavior of a novel pH-sensitive drug carrier for colon delivery

2008 ◽  
Vol 62 (2) ◽  
pp. 183-193 ◽  
Author(s):  
Dong-Ying Xu ◽  
Guang-Ji Li ◽  
Zheng-Fu Liao ◽  
Xiao-Hong He
Keyword(s):  
Controlled Release ◽  
Drug Carrier ◽  
Ph Sensitive ◽  
Release Behavior ◽  
Colon Delivery

Controlled Release of Doxycycline by Magnetized Microporous MIL53(Fe); Focus on Magnetization and Drug Loading

2018 ◽  
Vol 16 (1) ◽  
pp. 42-50 ◽  
Author(s):  
Shakiba Naeimi ◽  
Hossein Faghihian
Keyword(s):  
Drug Delivery ◽  
Controlled Release ◽  
Drug Loading ◽  
In Vitro Release ◽  
Time Intervals ◽  
Drug Content ◽  
Releasing Process ◽  
Phosphate Buffered Saline ◽  
Vitro Release

Background: In this research, MIL-53(Fe) was magnetized and the performance of the magnetized material as a drug delivery system for doxycycline was studied. Objectives: The experiments were designed to load the magnetic delivery compounds with different amount of the drug. Methods: The in vitro release rate of doxycycline from magnetic MIL-53(Fe) with different drug content into saline buffered fluid (SBF, pH=7.4) and phosphate buffered saline (PBS, pH=3) was then studied. Results: The results showed that the releasing process of the drug in PBS media achieved the equilibration within 48h with 98% of releasing efficiency, while the releasing process in SBF media (pH=7.4) was slower and the equilibrium was established within 264 h with the releasing efficiency of 95%. The amount of the released doxycycline from the samples with different drug content was measured at various time intervals. Conclusion: It was concluded that in PBS media after 75 h, 85, 95 and 98% of loaded doxycycline released, respectively, from the sample containing 22, 32 and 35% of the drug. In SBF media, the release was slower and after 350 h, 82, 91 and 95% of loaded doxycycline released from the samples, respectively, containing 22, 32 and 35 % of the drug. The results of this study indicated that by use of drugreleasing profile and selecting appropriate carrier dose, the released amount of the drug into the patient body can be controlled.

scholarly journals In-Vitro Cytotoxicity and Anticancer Drug Release Behavior of Methionine - Coated Magnetite Nanoparticles As Carriers.

2021 ◽  
Author(s):  
Faten Eshrati Yeganeh ◽  
Amir Eshrati Yeganeh ◽  
Bahareh Farasati Far ◽  
Iman Akbarzadeh ◽  
Sameer Quazi ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Amino Acid ◽  
Drug Release ◽  
Drug Loading ◽  
Average Particle Size ◽  
Mcf10a Cell ◽  
Core Shell ◽  
Average Particle ◽  
Release Behavior

Abstract An innovative and customized drug delivery system for in vitro cancer treatment has been developed successfully by a simple one-step method. A CoFe2O4@Methionine core-shell nanoparticle was prepared by the reflux assay, in which amino acid on the surface makes the ferrite biocompatible, enhances the chemical stability of the compound, and increases the drug loading capacity. The synthesized nanoparticles were evaluated using SEM, TEM, FTIR, and VSM, while XRD and TGA analysis verified the presence of a coating amino acid on the surface of CoFe2O4. The appearance of a new peak for C≡N in the FTIR spectrum validates the synthesis of a letrozole-loaded carrier. Both uncoated CoFe2O4 and methionine-coated CoFe2O4 nanoparticles behave super-paramagnetically at room temperature, with saturation values of 46 emu/g and 16.8 emu/g, respectively. SEM and TEM were used to characterize the morphology and size of samples, revealing that the average particle size was around 28–29 nm. The loading of Letrozole and the effect of pH (5, 7.4) on the release behavior of the carrier were studied. The result of the drug release in pH (5) was about 88% higher than pH (7.4). Also, the preparation has been evaluated for determining its cytotoxicity using MCF-7, MDA-MB-231, and MCF10A cell lines as an in vitro model, and the results of in vitro experiments showed that CoFe2O4@Methionine could significantly reduce cancer in the cell model. These results demonstrate that core-shell nanoparticles were prepared that are biocompatible and have potential use as drug delivery.

scholarly journals Hierarchically electrospraying a PLGA@chitosan sphere-in-sphere composite microsphere for multi-drug-controlled release

2020 ◽  
Vol 7 (4) ◽  
pp. 381-390
Author(s):  
Zhu Liu ◽  
Weilong Ye ◽  
Jingchuan Zheng ◽  
Qindong Wang ◽  
Guowu Ma ◽  
...  
Keyword(s):  
Controlled Release ◽  
Drug Loading ◽  
Uv Spectrophotometry ◽  
Composite Microsphere ◽  
Ionization Time ◽  
Composite Microspheres ◽  
Flight Mass Spectrometry ◽  
Sequential Administration ◽  
Cellular Behaviors

Abstract Sequential administration and controlled release of different drugs are of vital importance for regulating cellular behaviors and tissue regeneration, which usually demands appropriate carriers like microspheres (MS) to control drugs releases. Electrospray has been proven an effective technique to prepare MS with uniform particle size and high drug-loading rate. In this study, we applied electrospray to simply and hierarchically fabricate sphere-in-sphere composite microspheres, with smaller poly(lactic-co-glycolic acid) MS (∼8–10 μm in diameter) embedded in a larger chitosan MS (∼250–300 μm in diameter). The scanning electron microscopy images revealed highly uniform MS that can be accurately controlled by adjusting the nozzle diameter or voltage. Two kinds of model drugs, bovine serum albumin and chlorhexidine acetate, were encapsulated in the microspheres. The fluorescence-labeled rhodamine-fluoresceine isothiocyanate (Rho-FITC) and ultraviolet (UV) spectrophotometry results suggested that loaded drugs got excellent distribution in microspheres, as well as sustained, slow release in vitro. In addition, far-UV circular dichroism and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) results indicated original secondary structure and molecular weight of drugs after electrospraying. Generally speaking, our research proposed a modified hierarchically electrospraying technique to prepare sphere-in-sphere composite MS with two different drugs loaded, which could be applied in sequential, multi-modality therapy.

scholarly journals Development of Hydrophilic Drug Encapsulation and Controlled Release Using a Modified Nanoprecipitation Method

Processes ◽  
2019 ◽  
Vol 7 (6) ◽  
pp. 331
Author(s):  
Jiang Xu ◽  
Yuyan Chen ◽  
Xizhi Jiang ◽  
Zhongzheng Gui ◽  
Lei Zhang
Keyword(s):  
Lactic Acid ◽  
Controlled Release ◽  
Drug Loading ◽  
Continuous Phase ◽  
Poly Lactic Acid ◽  
Feed Concentration ◽  
Hydrophilic Drugs ◽  
Hydrophilic Drug ◽  
Nanoprecipitation Method

The improvement of the loading content of hydrophilic drugs by polymer nanoparticles (NPs) recently has received increased attention from the field of controlled release. We developed a novel, simply modified, drop-wise nanoprecipitation method which separated hydrophilic drugs and polymers into aqueous phase (continuous phase) and organic phase (dispersed phase), both individually and involving a mixing process. Using this method, we produced ciprofloxacin-loaded NPs by Poly (d,l-lactic acid)-Dextran (PLA-DEX) and Poly lactic acid-co-glycolic acid-Polyethylene glycol (PLGA-PEG) successfully, with a considerable drug-loading ability up to 27.2 wt% and an in vitro sustained release for up to six days. Drug content with NPs can be precisely tuned by changing the initial drug feed concentration of ciprofloxacin. These studies suggest that this modified nanoprecipitation method is a rapid, facile, and reproducible technique for making nano-scale drug delivery carriers with high drug-loading abilities

Sign in / Sign up

Export Citation Format

Share Document