scholarly journals Synthesis and In Vitro Evaluation of Aspartic Acid Based Microgels for Sustained Drug Delivery

Gels ◽  
2021 ◽  
Vol 8 (1) ◽  
pp. 12
Author(s):  
Muhammad Suhail ◽  
An Xie ◽  
Jia-Yu Liu ◽  
Wan-Chu Hsieh ◽  
Yu-Wen Lin ◽  
...  

The main focus of the current study was to sustain the releasing behavior of theophylline by fabricated polymeric microgels. The free radical polymerization technique was used for the development of aspartic acid-co-poly(2-acrylamido-2-methylpropanesulfonic acid) microgels while using various combinations of aspartic acid, 2-acrylamido-2-methylpropanesulfonic acid, and N′,N′-methylene bisacrylamide as a polymer, monomer, and cross-linker, respectively. Ammonium peroxodisulfate and sodium hydrogen sulfite were used as initiators. Characterizations such as DSC, TGA, SEM, FTIR, and PXRD were performed for the fabricated microgels to assess their thermal stability with unreacted polymer and monomer, their surface morphology, the formation of a new polymeric system of microgels by evaluating the cross-linking of functional groups of the microgels’ contents, and to analyze the reduction in crystallinity of the theophylline by fabricated microgels. Various studies such as dynamic swelling, drug loading, sol–gel analysis, in vitro drug release studies, and kinetic modeling were carried out for the developed microgels. Both dynamic swelling and percent drug release were found higher at pH 7.4 as compared to pH 1.2 due to the deprotonation of functional groups of aspartic acid and AMPS. Similarly, sol–gel analysis was performed and an increase in gel fraction was observed with the increasing concentration of microgel contents, while sol fraction was decreased. Conclusively, the prepared carrier system has the potential to sustain the release of the theophylline for an extended period of time.

Author(s):  
GEETHA V. S. ◽  
MALARKODI VELRAJ

Objective: To formulate, optimize and evaluate 5-fluorouracil loaded liquorice crude protein nanoparticles for sustained drug delivery using Box-Behnken design. Methods: 5-fluorouracil (5-FU) loaded liquorice crude protein (LCP) nanoparticles were prepared by desolvation method using ethanol-water (1:2 ratio), Tween-80 (2%v/v) as stabilizing agent and gluteraldehyde (8% v/v) as cross linking agent. The optimization of prepared nanoparticles was carried out using Box-Behnken design with 3 factors 2 levels and 3 responses. The independent variables were A)5-FU concentration B)LCP concentration and C) sonication time while the responses were R1) Drug entrapment efficiency R2) Drug loading efficiency and R3) Particle size. The correlation between factors and responses were studied through response surface plots and mathematical equations. The nanoparticles were evaluated for FTIR, physicochemical properties like particle size and zeta potential by Photon correlation spectroscopy (PCS) and surface morphology by TEM. The entrapment efficiency, drug loading efficiency and in vitro drug release studies in PBS pH 7.4 (24 h) were carried out. The observed values were found to be in close agreement with the predicted value obtained from the optimization process. Results: 5-fluorouracil loaded LCP nanoparticles were prepared by desolvation method, the optimization was carried out by Box-Behnken design and the final formulation was evaluated for particle size (301.1 nm), zeta-potential (-25.8mV), PDI(0.226), with entrapment efficiency (64.07%), drug loading efficiency (28.54%), in vitro drug release (65.2% in 24 h) respectively. The formulated nanoparticles show Higuchi model drug release kinetics with sustained drug delivery for 24 h in pH7.4 buffer. Conclusion: The results were proved to be the most valuable for the sustained delivery of 5-Fluorouracil using liquorice crude protein as carrier. 5-FU–LCP nanoparticles were prepared using Tween-80 as stabilizing agent and gluteraldehyde as cross-linking agent to possess ideal sustained drug release characteristics.


2021 ◽  
Vol 7 (2) ◽  
pp. 672-675
Author(s):  
Katharina Wulf ◽  
Stefan Raggl ◽  
Thomas Eickner ◽  
Gerrit Paasche ◽  
Niels Grabow

Abstract Sterilization processes ensure sterility of drug delivery systems, but may negatively affect the properties of biomaterials and incorporated drugs by changing their physical, chemical, mechanical properties and drug release behaviour. Therefore, it is important to investigate their influence. In this study, the influence of ethylene oxide (EtO) sterilization on the drug loading and release behaviour of incorporated Diclofenac (DCF) in a Poly-L-lactide (PLLA) coating and Dexamethasone (DMS) in the silicone carrier is presented. Silicone samples containing DMS were coated with PLLA containing DCF varying in layer thickness (5, 10, and 20 μm). Half of the samples underwent EtO sterilization, the other half was not sterilized. All un-/sterilized sample surfaces were in view of the morphology and hydrophilicity examined. Furthermore, in vitro release studies of DMS and DCF were conducted. The sterilized sample surfaces showed no morphological and hydrophilicity changes. The DCF and DMS loadings were similar for the sterile and untreated samples. This also applied to the in vitro DMS release profiles apart from the end of the studies where slight differences were evident. The results indicate that both drugs loaded in the polymer coating and the silicone were not impaired by the sterilization process. Thus, EtO sterilization appears suitable for DMS containing silicone and DCF incorporated PLLA coatings as a dual drug delivery system.


Gels ◽  
2021 ◽  
Vol 7 (2) ◽  
pp. 68
Author(s):  
Muhammad Suhail ◽  
Yi-Han Hsieh ◽  
Arshad Khan ◽  
Muhammad Usman Minhas ◽  
Pao-Chu Wu

Different combinations of polymers, aspartic acid (ASP), alginic acid (AL), and monomer acrylic acid (AA) were crosslinked in the presence of an initiator ammonium peroxodisulfate (APS) and cross-linker ethylene glycol dimethacrylate (EGDMA) to develop aspartic acid/alginic acid-co-poly(acrylic acid) (ASP/ALPAA) (semi-interpenetrating polymer network (SIPN)) hydrogels by the free radical polymerization technique for the controlled delivery of ibuprofen (IBP). Various studies such as dynamic swelling studies, drug loading, in vitro drug release and sol−gel analysis were carried out for the hydrogels. Higher swelling was observed at higher pH 7.4 as compared to lower pH 1.2, due to the presence of carboxylic groups of polymers and the monomer. Hence, pH-dependent swelling was exhibited by the developed hydrogels which led to a pH-dependent drug release and vice versa. The structural properties of the hydrogels were assessed by FTIR, PXRD, TGA, DSC, and SEM which confirmed the fabrication and stability of the developed structure. FTIR analysis revealed the reaction of both polymers with the monomer during the polymerization process and confirmed the overlapping of the monomer on the backbone of the both polymers. The disappearance of high intense crystalline peaks and the encapsulation of the drug by the hydrogel network was confirmed by PXRD. TGA and DSC showed that the developed hydrogels were thermally more stable than their basic ingredients. Similarly, the surface morphology of the hydrogels was analyzed by SEM and showed a smooth surface with few pores. Conclusively, ASP/ALPAA hydrogels have the potential to deliver IBP for a long period of time in a controlled way.


2019 ◽  
Vol 1 (1) ◽  
pp. 18-24
Author(s):  
Lakshmanaperumal Sundarabharathi ◽  
Mahendran Chinnaswamy ◽  
Hemalatha Parangusan ◽  
Deepalekshmi Ponnamma ◽  
Mariam Al Ali Al-Maadeed

Hydroxyapatite (Ca5(PO4)3OH) is a well-known bioceramics material used in medical applications because of its ability to form direct chemical bonds with living tissues. In this context, we investigate the biocompatibility and dielectric properties of Sr2+-substituted hydroxyapatite nanoparticles were synthesized by sol-gel method. The influence of strontium on the crystal structure, functional group, morphological, electrical properties, and biocompatibility of as-synthesized nano-hydroxyapatite samples was analyzed using X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy and field emission scanning electron microscopy (FE-SEM). Dielectrical properties of the bioactive Sr-HA sample were investigated by a dielectric impedance spectroscopy method. The observed results illustrate the incorporation of Sr2+ ions in the apatite lattice could influence the pure HA properties, by reducing the crystallite size and crystallinity quite consistent with the morphology variation. The ac conductivity (σac) increased with an increasing applied frequency confirmed that prepared HA sample exhibited the universal power law nature. Further, the in vitro drug loading and release studies using doxycycline as a model drug demonstrate that the Sr2+ -HA nanoparticles show high drug adsorption capacity and sustained drug release. Thus, the improved bioceramics system could be a promising candidate for future biomedical applications.


2020 ◽  
Author(s):  
Reedwan Bin Zafar Auniq ◽  
Namon Hirun ◽  
Upsorn Boonyang

Bioactive glass ceramics (BGCs) have been used in orthopedic and dentistry due to having better osteoconductive and osteostimulative properties. This study aimed to evaluate and compare the drug release properties of two different BGCs; 45S5 and S53P4. The BGCs were composed with four phases of SiO2 – CaO – Na2O – P2O5 system, synthesized by sol–gel method using dual templates; a block-copolymer as mesoporous templates and polymer colloidal crystals as macroporous templates, called three-dimensionally ordered macroporous-mesoporous bioactive glass ceramics (3DOM-MBGCs). In vitro bioactivity test performed by soaking the 3DOM-MBGCs in simulated body fluid (SBF) at 37°C. The results indicated that, the 45S5 have the ability to grow hydroxyapatite-like layer on the surfaces faster than S53P4. Gentamicin drug was used to examine in vitro drug release properties in phosphate buffer solution (PBS). The amount of drug release was quantified through UV/Vis spectroscopy by using o-phthaldialdehyde reagent. S53P4 showed high drug loading content. The outcome of drug release in PBS showed that both S53P4 and 45S5 exhibited a slowly continuous gentamicin release. The resultant drug release profiles were fitted to the Peppas-Korsmeyer model to establish the predominant drug release mechanisms, which revealed that the kinetics of drug release from the glasses mostly dominated by Fickian diffusion mechanism.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Kyle Battiston ◽  
Ian Parrag ◽  
Matthew Statham ◽  
Dimitra Louka ◽  
Hans Fischer ◽  
...  

AbstractPolymeric drug carriers are widely used for providing temporal and/or spatial control of drug delivery, with corticosteroids being one class of drugs that have benefitted from their use for the treatment of inflammatory-mediated conditions. However, these polymer-based systems often have limited drug-loading capacity, suboptimal release kinetics, and/or promote adverse inflammatory responses. This manuscript investigates and describes a strategy for achieving controlled delivery of corticosteroids, based on a discovery that low molecular weight corticosteroid dimers can be processed into drug delivery implant materials using a broad range of established fabrication methods, without the use of polymers or excipients. These implants undergo surface erosion, achieving tightly controlled and reproducible drug release kinetics in vitro. As an example, when used as ocular implants in rats, a dexamethasone dimer implant is shown to effectively inhibit inflammation induced by lipopolysaccharide. In a rabbit model, dexamethasone dimer intravitreal implants demonstrate predictable pharmacokinetics and significantly extend drug release duration and efficacy (>6 months) compared to a leading commercial polymeric dexamethasone-releasing implant.


2012 ◽  
Vol 584 ◽  
pp. 460-464 ◽  
Author(s):  
M Gajendiran ◽  
S. Balasubramanian

. A series of biodegradable amphiphilic tri-block copolymers (PLGA–PEG–PLGA) have been derived from the diblock copolymer poly (lactic–co–glycolic acid (PLGA)) and polyethylene glycol (PEG). The mycobacterium tuberculosis (MTB) drug pyrazinamide (PZA) loaded polymer nanoparticles (NPs) have been prepared by probe-sonication followed by w/o/w double emulsification technique. The copolymers have been characterized by FTIR and 1HNMR spectroscopic techniques, TG-DTA analysis, GPC analysis and powder XRD pattern. The MTB drug loaded polymeric NPs have been characterized by FESEM, powder XRD, HRTEM and XPS analysis. The drug loading efficiency, drug content and in vitro drug release studies have been carried out by spectrophotometry. The drug loading efficiency and drug content of triblock copolymeric NPs were higher than these of diblock copolymeric microparticles (MPs). The in vitro drug release studies indicate that the NPs exhibit initial burst release followed by controlled release of PZA for longer durations. The drug release kinetics mechanism has been evaluated by zero order, first order, Korsemeyer-Peppas (KP) and Higuchi models.


2012 ◽  
Vol 602-604 ◽  
pp. 231-234
Author(s):  
Min Peng Zhu ◽  
Su Hong Li

Epichlorohydrin crosslinked starch microspheres (ECMs) were synthesized with soluble starch as a raw material and epichlorohydrin as a crosslinker. The characteristics of ECMs were investigated by Scanning Electron Microscopy (SEM) and Fourier Transform InfraRed spectroscopy (FT-IR).The drug loading and in vitro release properties of ECMs were studied using arginine as a model drug. The results indicate that ECMs have a spherical morphology with average diameter about 7μm. The drug loading studies show that after absorption for 1.5 h, the largest amount of drug (drug loading 31mg/g) is loaded when the quantity ratio of ECMs to arginine is 2. In-vitro release studies indicate that the ECMs are effective in controlled releasing arginine over an extended period of about 25 h.


INDIAN DRUGS ◽  
2014 ◽  
Vol 51 (07) ◽  
pp. 31-38
Author(s):  
Gurudev Kruthi ◽  
◽  
B. V. Basavaraj ◽  
S. Bharath ◽  
R. Deveswaran ◽  
...  

The main aim of the present work was to formulate and evaluate sustained release multiparticulate gastroretentive delivery system of cinnarizine. The microspheres were prepared by solvent evaporation method by using Eudragit RS 100 as a polymer in varying ratios. The prepared microspheres were evaluated for drug – polymer compatibility studies, micromeritic properties, drug entrapment efficiency, in vitro buoyancy and drug release studies. The mean particle size increased with increase in polymer concentration, ranging between 60.33 μm to 144.88 μm. FT IR studies showed that the drug and polymer were compatible with each other. The entrapment efficiency decreased with increase in the polymer concentration with values of 50%, 33.3% and 25% respectively. The microspheres floated upto 9 h over the surface of the gastric buffer medium and the buoyancy percentage was found to be in the range of 64.3 – 76.2%. In vitro drug release studies showed that the prepared microspheres exhibited prolonged drug release upto 62.89% for more than 9 h. The mechanism of drug release was found to be a combination of both peppas and matrix kinetics. Thus the developed floating microspheres of cinnarizine may be used as sustained drug delivery system for increasing the therapeutic efficacy with an improved patient compliance.


Author(s):  
Neeraj Agrawal ◽  
M.J. Chandrasekar ◽  
U.V. Sara ◽  
Rohini A.

A macromolecular prodrug of didanosine (ddI) for oral administration was synthesized and evaluated for in-vitro drug release profile. Didanosine was first coupled to 2-hydroxy ethyl methacrylate (HEMA) through a succinic spacer to form HEMA-Suc-ddI monomeric conjugate which was subsequently polymerized to yield Poly(HEMA-Suc-ddI) conjugate. The structures of the synthesized compounds were characterized by FT-IR, Mass and 1H-NMR spectroscopy. The prodrug was subjected for in-vitro drug release studies in buffers of pH 1.2 and 7.4 mimicking the upper and lower GIT. The results showed that the drug release from the polymeric backbone takes place in a sustained manner over a period of 24 h and the amount of drug released was comparatively higher at pH 7.4 indicating that the drug release takes place predominantly at the alkaline environment of the lower GIT rather than at the acidic environment of the upper GIT. This pH dependent sustained drug release behavior of the prodrug may be capable of reducing the dose limiting toxicities by maintaining the plasma drug level within the therapeutic range and increasing t1/2 of ddI. Moreover, the bioavailability of the drug should be improved as the prodrug releases ddI predominantly in the alkaline environment which will reduce the degradation of ddI in the stomach acid.


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