Doxorubicin release from optimized electrospun polylactic acid nanofibers

2016 ◽  
Vol 47 (1) ◽  
pp. 71-88 ◽  
Author(s):  
Amir Doustgani
Keyword(s):  
Differential Scanning Calorimetry ◽  
Drug Release ◽  
Polylactic Acid ◽  
Fiber Diameter ◽  
Experimental Result ◽  
Coefficient Of Determination ◽  
Release Mechanism ◽  
Burst Release ◽  
Fiber Morphology ◽  
Scanning Calorimetry

Electrospinning has been known as an efficient method for fabrication of polymer nanofibers. In this study, an electrospun nanofibrous mats based on polylactic acid with a defined release using doxorubicin was developed. The effects of process parameters, such as concentration, distance, applied voltage, temperature and flow rate on the mean diameter of electrospun doxorubicin-loaded polylactic acid nanofibers were investigated. The fiber morphology and mean fiber diameter of prepared nanofibers were investigated by scanning electron microscopy. Differential scanning calorimetry was employed to identify the presence of doxorubicin within nanofibers. Response surface methodology based on a five-level, five-variable central composite design was used to model the average diameter of electrospun polylactic acid/doxorubicin nanofibers. Mean fiber diameter was correlated to these variables by using a polynomial function at a 95% confidence level. The coefficient of determination of the model was found to be 0.93. The predicted fiber diameter was in good agreement with the experimental result. Differential scanning calorimetry results showed that the doxorubicin was loaded into the nanofibers successfully. In vitro drug release in phosphate-buffered solution and acetate buffer for the optimized and non-optimized samples demonstrated that diffusion is the dominant drug release mechanism for drug-loaded fibers. The initial burst release was observed for non-optimized nanofibers compared to optimized nanofibers. Optimized drug-loaded polylactic acid nanofibers could be good candidates for biomedical applications.

The Development of Pemetrexed Diacid-Loaded Gelatin-Cloisite 30B (MMT) Nanocomposite for Improved Oral Efficacy Against Cancer: Characterization, In-Vitro and Ex-Vivo Assessment

2020 ◽  
Vol 17 (3) ◽  
pp. 246-256
Author(s):  
Kriti Soni ◽  
Ali Mujtaba ◽  
Md. Habban Akhter ◽  
Kanchan Kohli
Keyword(s):  
Drug Release ◽  
Oral Delivery ◽  
Ex Vivo ◽  
Confocal Laser ◽  
Release Mechanism ◽  
Scanning Calorimetry ◽  
Sem Images ◽  
Cloisite 30B ◽  
Ft Ir

Aim: The intention of this investigation was to develop Pemetrexed Diacid (PTX)-loaded gelatine-cloisite 30B (MMT) nanocomposite for the potential oral delivery of PTX and the in vitro, and ex vivo assessment. Background: Gelatin/Cloisite 30 B (MMT) nanocomposites were prepared by blending gelatin with MMT in aqueous solution. Methods: PTX was incorporated into the nanocomposite preparation. The nanocomposites were investigated by Fourier Transmission Infra Red Spectroscopy (FT-IR), Differential Scanning Calorimetry (DSC), Scanning Electron Microscope (SEM) X-Ray Diffraction (XRD) and Confocal Laser Microscopy (CLSM). FT-IR of nanocomposite showed the disappearance of all major peaks which corroborated the formation of nanocomposites. The nanocomposites were found to have a particle size of 121.9 ± 1.85 nm and zeta potential -12.1 ± 0.63 mV. DSC thermogram of drug loaded nanocomposites indicated peak at 117.165 oC and 205.816 oC, which clearly revealed that the drug has been incorporated into the nanocomposite because of cross-linking of cloisite 30 B and gelatin in the presence of glutaraldehyde. Results: SEM images of gelatin show a network like structure which disappears in the nanocomposite. The kinetics of the drug release was studied in order to ascertain the type of release mechanism. The drug release from nanocomposites was in a controlled manner, followed by first-order kinetics and the drug release mechanism was found to be of Fickian type. Conclusion: Ex vivo gut permeation studies revealed 4 times enhancement in the permeation of drug present in the nanocomposite as compared to plain drug solution and were further affirmed by CLSM. Thus, gelatin/(MMT) nanocomposite could be promising for the oral delivery of PTX in cancer therapy and future prospects for the industrial pharmacy.

scholarly journals Development of Controlled-Release Carbamide Peroxide Loaded Nanoemulgel for Tooth Bleaching: In Vitro and Ex Vivo Studies

2021 ◽  
Vol 14 (2) ◽  
pp. 132
Author(s):  
Siriporn Okonogi ◽  
Adchareeya Kaewpinta ◽  
Sakornrat Khongkhunthian ◽  
Pisaisit Chaijareenont
Keyword(s):  
Drug Release ◽  
Solid Dispersion ◽  
Solid Dispersions ◽  
Tooth Bleaching ◽  
Polymer Mixture ◽  
Release Mechanism ◽  
Burst Release ◽  
Order Kinetic ◽  
Carbamide Peroxide ◽  
Periodontal Tissues

Burst release of carbamide peroxide (CP) from traditional hydrogels causes severe inflammation to periodontal tissues. The present study explores the development of a novel CP nanoemulgel (CP-NG), an oil-in-water nanoemulsion-based gel in which CP was loaded with a view to controlling CP release. CP solid dispersions were prepared, using white soft paraffin or polyvinylpyrrolidone-white soft paraffin mixture as a carrier, prior to formulating nanoemulsions. It was found that carrier type and the ratio of CP to carrier affected drug crystallinity. Nanoemulsions formulated from the optimized CP solid dispersions were used to prepare CP-NG. It was found that the ratio of drug to carrier in CP solid dispersions affected the particle size and zeta potential of the nanoemulsions as well as drug release behavior and tooth bleaching efficacy of CP-NG. Drug release from CP-NG followed a first-order kinetic reaction and the release mechanism was an anomalous transport. Drug release rate decreased with an increase in solid dispersion carriers. CP-NG obtained from the solid dispersion with a 1:1 ratio of CP to the polymer mixture is suitable for sustaining drug release with high tooth bleaching efficacy and without reduction of enamel microhardness. The developed CP-NG is a promising potential tooth bleaching formulation.

scholarly journals Effects of Starch Incorporation on the Physicochemical Properties and Release Kinetics of Alginate-Based 3D Hydrogel Patches for Topical Delivery

Pharmaceutics ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 719
Author(s):  
Sara Bom ◽  
Catarina Santos ◽  
Rita Barros ◽  
Ana M. Martins ◽  
Patrizia Paradiso ◽  
...  
Keyword(s):  
Drug Release ◽  
Release Kinetics ◽  
Research Work ◽  
Gelation Time ◽  
Topical Delivery ◽  
Release Mechanism ◽  
Release Kinetic ◽  
Burst Release ◽  
Critical Material ◽  
The Impact

The development of printable hydrogel inks for extrusion-based 3D printing is opening new possibilities to the production of new and/or improved pharmaceutical forms, specifically for topical application. Alginate and starch are natural polysaccharides that have been extensively exploited due to their biocompatibility, biodegradability, viscosity properties, low toxicity, and relatively low cost. This research work aimed to study the physicochemical and release kinetic effects of starch incorporation in alginate-based 3D hydrogel patches for topical delivery using a quality by design approach. The incorporation of a pregelatinized starch is also proposed as a way to improve the properties of the drug delivery system while maintaining the desired quality characteristics. Critical material attributes and process parameters were identified, and the sensitivity and adequacy of each parameter were statistically analyzed. The impact of alginate, starch, and CaCl2·2H2O amounts on relevant quality attributes was estimated crosswise. The amount of starch revealed a synergetic impact on porosity (p = 0.0021). An evident increase in the size and quantity of open pores were detected in the as printed patches as well as after crosslinking (15.6 ± 5.2 µm). In vitro drug release studies from the optimized alginate-starch 3D hydrogel patch, using the probe Rhodamine B, showed an initial high burst release, followed by a controlled release mechanism. The results obtained also showed that the viscoelastic properties, printing accuracy, gelation time, microstructure, and release rates can be modulated by varying the amount of starch added to the system. Furthermore, these results can be considered an excellent baseline for future drug release modulation strategies.

193 IN VITRO DEVELOPMENT OF A LESS INVASIVE HORMONE DELIVERY SYSTEM TO SUPEROVULATE TIGERS

2010 ◽  
Vol 22 (1) ◽  
pp. 255
Author(s):  
J. T. Aaltonen ◽  
S. Singh ◽  
L. R. Fogueri ◽  
N. S. Mulla ◽  
N. M. Loskutoff
Keyword(s):  
Differential Scanning Calorimetry ◽  
Fourier Transform ◽  
Benzyl Alcohol ◽  
Release Rate ◽  
Fourier Transform Infrared ◽  
Release Profile ◽  
Infrared Spectrometry ◽  
Burst Release ◽  
Fourier Transform Infrared Spectrometry ◽  
Scanning Calorimetry

Current administration of FSH for the purpose of superovulation of tigers is achieved through serial injections or subcutaneous osmotic pump (Blevins B et al. 2009 J. Reprod. Fertil. 21, 153 abst). Both have limitations, which are pulsatile hormone fluctuations and multiple anesthesia events for pump insertion and removal, respectively. In vivo attempts to superovulate tigers using aluminum hydroxide gel [Al(OH)3] proved unsuccessful by fecal hormone enzyme immunoassay. In addition, Al(OH)3 raises the potential for an immune response to foreign FSH. An inert, biodegradable, and FDA-approved polylactide-co-glycolide polymer-based in situ gel forming system eliminates the problems above with a single injection delivery, allowing a more natural sustained release of FSH. Polymer solutions were made using a solvent mixture of benzyl benzoate (BB), or benzyl alcohol (BA), or both. Porcine FSH (Folltropin®-V, Bioniche, Belleville, Ontario, Canada) was incorporated into the polymer solution via sonication, which gelled upon contact with interstitial fluid. Polymer composition (ratio of lactide to glycolide) and concentration and ratio of BB to BA parameters can be manipulated to achieve a desired release profile. Two formulations (F1 and F2) were created with differing percentages of composition for the purpose of recreating a controlled release rate of 100 NIH-FSH-P1 reference standard mg/day (pump output). The FSH polymer was injected into 15 mL of PBS (pH 7.4 in a 37°C shaker bath at 30 rpm), which instantly formed a gel. One milliliter of PBS was sampled every 24 h and replenished with fresh PBS. The amount of FSH was determined by measuring UV absorbance at 290 nm (Shimadzu 1600 UV-visible spectrophotometer; Shimadzu Scientific Instruments, Columbia, MD, USA). Formulation F1 showed a higher initial burst release than F2 (61.5% v. 35.8% of total incorporated hormone) as a result of the use of 100% BA as a solvent. Benzyl alcohol is more hydrophilic than BB, leaching out of the polymer-FSH solution faster and leading to a greater release of the hydrophilic FSH. Both formulations showed a biphasic release pattern in which the first phase was relatively faster than the second phase. Although F2 (80% BA-20% BB solvent) was successful in reducing the burst release by half, the day-to-day profile is below target. Our results indicate that F2 has a better release profile than F1 for inducing folliculogenesis and can be improved by manipulating formulation parameters such as increasing the polymer concentration and BA:BB ratio of the solvents. Using Fourier transform infrared spectrometry and differential scanning calorimetry, hormones before gel incorporation were compared to those released. Fourier transform infrared spectrometry and differential scanning calorimetry data suggest that the gel does not affect the conformational stability of FSH. It is therefore possible to manipulate a gel to mimic the release rate of a proven osmotic pump without compromising the functionality of the protein hormone, potentially reducing the number of surgeries or injections to superovulate tigers.

Study on Morphology and Structure of Wax Crystals in Waxy Crudes at Apex Temperature of Wax Precipitation

2013 ◽  
Vol 318 ◽  
pp. 293-296 ◽  
Author(s):  
Shi Ze Yi ◽  
Peng Gao
Keyword(s):  
Differential Scanning Calorimetry ◽  
Fractal Dimension ◽  
Crystal Morphology ◽  
Experimental Result ◽  
Strong Positive Correlation ◽  
Scanning Calorimetry ◽  
Wax Precipitation ◽  
Morphology And Structure ◽  
Wax Crystal ◽  
Wax Crystals

The apex temperature of wax precipitation was measured with fractal dimension characterizing the wax crystal morphology, and Differential Scanning Calorimetry (DSC), respectively. The experimental result revealed that the concentration of precipitated wax in virgin waxy crudes had the strong positive correlation with the fractal dimension of wax crystals. At the apex temperature, the wax crystals changed from tiny microscopic spots to clear and visible ones, with their morphology and structure becoming more intricate.

scholarly journals “EFFECT OF CROSSLINKING AGENT ON DEVELOPMENT OF GASTRORETENTIVE MUCOADHESIVE MICROSPHERES OF RISEDRONATE SODIUM”

2018 ◽  
Vol 10 (4) ◽  
pp. 133 ◽  
Author(s):  
Shweta Gedam ◽  
Pritee Jadhav ◽  
Swati Talele ◽  
Anil Jadhav
Keyword(s):  
Differential Scanning Calorimetry ◽  
Particle Size ◽  
Drug Release ◽  
Calcium Chloride ◽  
Crosslinking Agent ◽  
Entrapment Efficiency ◽  
Scanning Calorimetry ◽  
Scanning Electron ◽  
Polymer Ratio

Objective: The present investigation was undertaken to develop and evaluate a gastroretentive mucoadhesive microspheres of anti-osteoporosis drug risedronate sodium to enhance the residence time and drug release by studying the effect of the crosslinking agent to obtain the best formulation with reduced particle size and good in vitro mucoadhesion strength.Methods: Selected drug risedronate sodium is a potent pyridinyl bisphosphonate used for the treatment of osteoporosis, and other bone disorders. Microspheres using sodium alginate as a polymer and calcium chloride solution as a cross-linker were prepared successfully by the emulsification crosslinking method. The 23 factorial design was used to study the effects of various variables like a drug: polymer ratio, crosslinking agent concentration and crosslinking time on the particle size and in vitro mucoadhesion strength. All these formulations were evaluated for entrapment efficiency, percentage yield and cumulative drug release. F1 batch was selected as best formulation and evaluated for scanning electron microscopy, fourier transforms infrared spectroscopy, differential scanning calorimetry, stability study.Results: Design batches were evaluated for percent yield (61.29-89.33%), % entrapment efficiency (42.25±0.620-62.58±0.330), mucoadhesion strength (68.15±0.37-82.24±0.72%) and drug release at 12 h (67-84%). Among the microspheres formulation, an F1 batch of (0.5:1) drug: polymer concentration and at 4% concentration of calcium chloride as a crosslinker was considered best formulation with reduced particle size 32.85±0.774μm, % intro mucoadhesion. 82.24±0.72. In vitro mucoadhesion strength was increased with the increasing crosslinking time from 5 min to 10 min. The fourier transform infrared spectroscopy (FTIR) and differential scanning calorimetry (DSC) study showed no interaction between drug and polymer. X-ray diffraction (XRD) spectrum of microspheres indicates that drug particles are dispersed at the molecular level in the polymer matrices so no indication of the crystalline nature of the drug nature. Scanning electron microscopic (SEM) study showed that microspheres were spherical in shape with a smooth surface. F1 batch shows percentage cumulative drug release 84.07%. In vitro dissolution studies indicates that percent cumulative drug release from microspheres follows zero order kinetics plot which indicates controlled-release drug-delivery for 12 h which leads to control of plasma concentration.Conclusion: The results show that the formulation that contains (0.5:1) drug: polymer ratio, calcium chloride in 4% concentration and crosslinking time 10 min is the best one and can be utilized to formulate risedronate sodium mucoadhesive microspheres to enhance gastric residence time, improved patient compliance and reduction in the frequency of drug administration.

scholarly journals IN VITRO ENTRAPMENT AND RELEASE STUDIES OF LEVOFLOXACIN USING EPICHLOROHYDRIN-CROSSLINKED HYDROGEL

2019 ◽  
pp. 138-144
Author(s):  
ANGELI ANN S RESCOBER
Keyword(s):  
New Zealand ◽  
Drug Release ◽  
Release Rate ◽  
Drug Loading ◽  
Ophthalmic Solution ◽  
Antimicrobial Activities ◽  
Release Mechanism ◽  
Scanning Calorimetry ◽  
Polymer Ratio

Objective: This study aimed to optimize and evaluate the controlled release rate, ocular irritancy, and in vitro antimicrobial properties of levofloxacinentrapped in the epichlorohydrin-crosslinked hydrogel of sodium carboxymethyl cellulose (NaCMC) and gelatin.Materials and Methods: Various parameters such as polymer ratio, amount of crosslinker, temperature, reaction time, swelling capacity, and percentdrug loading were considered in Optimized levofloxacin hydrogel. Hydrogel preparations with higher amount of drug loaded were further analyzedto determine its in vitro drug release rate, ocular irritancy on New Zealand rabbits, and antimicrobial activities against Pseudomonas aeruginosaand Staphylococcus aureus. Optimized levofloxacin hydrogel (OLH) was then subjected to 3-month stability testing at 40 ± 2°C and 75 ± 5% relativehumidity in which samples were withdrawn at the end of each month for analysis.Results: Polymer groups with higher concentrations of NaCMC have higher swelling and drug loading capacities than those with higher gelatinconcentrations. Meanwhile, qualitative analysis using differential scanning calorimetry, Fourier-transform infrared spectroscopy, and scanningelectron microscopy verified the presence of levofloxacin in the epichlorohydrin-cross-linked hydrogel. Among the four polymer ratio, F3 was theoptimized hydrogel with drug-loaded concentration of 99.50%, which was within the acceptable assay limit of 0.5% levofloxacin solution based onUnited States Pharmacopeia monograph. It followed the Higuchi kinetic model with a drug release mechanism of super case 2 transport indicatinghydrogel swelling as a key factor for its controlled drug release. In vitro, antibacterial test against P. aeruginosa and S. aureus was sensitive to optimizedlevofloxacin hydrogel (OLH) with inhibitory diameter zones of 31.68 and 37.05 mm, respectively. Ocular irritancy test also showed that the OLH isnon-irritating on installation in the cul-de-sac of New Zealand rabbits.Conclusion: Optimized levofloxacin hydrogel was effective, non-irritating, and stable, which can be used as an alternative to conventional 0.5%levofloxacin ophthalmic solution.

Development of Chitosan and Polylactic Acid Based Methotrexate Intravitreal Micro-Implants to Treat Primary Intraocular Lymphoma: An In Vitro Study

2014 ◽  
Vol 136 (2) ◽  
Author(s):  
Soumyarwit Manna ◽  
James J. Augsburger ◽  
Zelia M. Correa ◽  
Julio A. Landero ◽  
Rupak K. Banerjee
Keyword(s):  
Drug Release ◽  
Polylactic Acid ◽  
Model Fit ◽  
External Beam Radiation ◽  
Intraocular Lymphoma ◽  
Therapeutic Window ◽  
Burst Release ◽  
Primary Intraocular Lymphoma ◽  
Beam Radiation ◽  
Micro Implants

Primary intraocular lymphoma (PIOL) is an uncommon but clinically and pathologically distinct form of non-Hodgkin's lymphoma. It provides a therapeutic challenge because of its diverse clinical presentations and variable clinical course. Currently available treatments for PIOL include intravenous multiple drug chemotherapy, external beam radiation therapy, and intravitreal methotrexate (MTX) injection. Each intravitreal injection of MTX is associated with potentially toxic peaks and subtherapeutic troughs of intraocular MTX concentration. Repetitive injections are required to maintain therapeutic levels of MTX in the eye. A sustained release drug delivery system is desired for optimized therapeutic release (0.2–2.0 μg/day) of MTX for over a period of 1 month to achieve effective treatment of PIOL. This study reports development of a unique intravitreal micro-implant, which administers therapeutic release of MTX over a period of 1 month. Chitosan (CS) and polylactic acid (PLA) based micro-implants are fabricated for different MTX loadings (10%, 25%, and 40% w/w). First, CS and MTX mixtures are prepared for different drug loadings, and lyophilized in Tygon® tubing to obtain CS-MTX fibers. The fibers are then cut into desired micro-implant lengths and dip coated in PLA for a hydrophobic surface coating. The micro-implant is characterized using optical microscopy, scanning electron microscopy (SEM), time of flight-secondary ion mass spectroscopy (ToF-SIMS), and differential scanning calorimetry (DSC) techniques. The release rate studies are carried out using a UV-visible spectrophotometer. The total release durations for 10%, 25%, and 40% w/w uncoated CS-MTX micro-implants are only 19, 29, and 32 h, respectively. However, the therapeutic release durations for 10%, 25%, and 40% w/w PLA coated CS-MTX micro-implants significantly improved to 58, 74, and 66 days, respectively. Thus, the PLA coated CS-MTX micro-implants are able to administer therapeutic release of MTX for more than 50 days. The release kinetics of MTX from the coated micro-implants is explained by (a) the Korsmeyer–Peppas and zero order model fit (R2 ∼ 0.9) of the first 60% of the drug release, which indicates the swelling of polymer and initial burst release of the drug; and (b) the first order and Higuchi model fit (R2 ∼ 0.9) from the tenth day to the end of drug release, implying MTX release in the therapeutic window depends on its concentration and follows diffusion kinetics. The PLA coated CS-MTX micro-implants are able to administer therapeutic release of MTX for a period of more than 1 month. The proposed methodology could be used for improved treatment of PIOL.

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