Enoxaparin-immobilized poly(ε-caprolactone)- based nanogels for sustained drug delivery systems

2014 ◽  
Vol 86 (5) ◽  
pp. 691-700 ◽  
Author(s):  
Ahmed A. Haroun ◽  
Amany M. El Nahrawy ◽  
Philipe Maincent

AbstractEnoxaparin-immobilized gelatin/poly(ε-caprolactone) (PCL) or Eudragit® RS230D nanogels in the presence of tetraethyl orthosilicate (TEOS) as polycondensation reagent were designed and characterized for their sustained drug delivery ability. Enoxaparin (anti-Xa 1000 UI/mL) was used as a model drug at different concentrations (300, 500, and 1000 UI/mL). The resulting nanogels were prepared using sol-gel technique and analyzed using several analytical tools such as: thermal analysis (DSC and TGA), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning and transmitting electron microscopes (SEM and TEM). In addition to particle size, zeta potential and in vitro release profiles were also investigated. A burst effect was observed, afterwards, the release rate became steady. The immobilization of enoxaparin into the gel network led to the formation of stable nanogels with ionic functional groups, which enable the efficient loading and sustainable release. The preliminary results showed that enoxaparin-immobilized PCL-based nanogels in this study can be utilized in the design of a sustained delivery system.

Polymers ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 2200
Author(s):  
Yuanyuan Wang ◽  
Yongyue Li ◽  
Jinghua Gong ◽  
Jinghong Ma

Here, we report a novel thermo-triggered-releasing microcapsule for liposoluble drug delivery. Monodisperse microcapsules with a poly(N-isopropylacrylamide-co-methacrylic acid) hydrogel shell and an oil core were successfully fabricated by a double coaxial microfluidic device. Fluorescent dye Lumogen Red F300 as a model liposoluble drug was dissolved in the oil core with controllable loading capacity. The volume phase transition temperature (VPTT) of the microcapsule was adjusted by copolymerizing with the hydrophilic methacrylic acid. The in vitro release study demonstrates that the shells shrink, leading to the thermo-triggered release of the model drug from the microcapsules at the environmental temperature above the VPTT, while the swollen hydrogel shells can protect the encapsulated drug from leakage and contamination below the VPTT. The proposed microcapsule is a promising liposoluble drug delivery system with controllable loading and smart thermo-triggered release.


Author(s):  
Muhammad Wahab Amjad ◽  
Maria Abdul Ghafoor Raja

The purpose of this study was to develop liposome-enriched Ketoprofen liposomal hydrogels and carry out in vitro release profile experiment. The aim was to achieve sustained topical drug delivery for extended time interval from liposomal gels. Phosphatidylcholine, Cholesterol and Ketoprofen were dissolved in chloroform/methanol (2:1, v/v) mixture and subsequently transferred to a flask attached to rotavapor. The liposomes were assessed for particle size and percent drug entrapment. F-7 and F-8 batches were found to be optimized batches having optimum sizes, drug entrapment efficiencies and cumulative drug releases. F-8 batch was further evaluated for stability. The results show that the prepared liposomes of Ketoprofen might turn out to be potential candidates for effective and safe sustained drug delivery thereby resulting in the reduction of dosing frequency.


Gels ◽  
2021 ◽  
Vol 7 (1) ◽  
pp. 10
Author(s):  
Muhammad Suhail ◽  
Arshad Khan ◽  
Jessica M Rosenholm ◽  
Muhammad Usman Minhas ◽  
Pao-Chu Wu

The aim of the current study was to fabricate naturally derived polymer based hydrogels for controlled release of diclofenac sodium (DS) for a long duration of time. In this research work, sodium alginate-co-poly(2-acrylamido-2-methyl propane sulphonic acid) (SA-co-poly(AMPS)) hydrogels were prepared by the free radical polymerization technique, where sodium alginate (SA) and 2-acrylamido-2-methyl propane sulphonic acid (AMPS) were used as the polymer and monomer while ammonium peroxodisulfate (APS) and N,N′-Methylene bisacrylamide (MBA) were used as the initiator and cross-linker, respectively. A swelling study was performed to determine the swelling index of developed hydrogels in both acidic (pH 1.2) and basic (pH 7.4) media and pH-independent swelling was observed due to the presence of AMPS. An in vitro release study was conducted to evaluate the percentage of drug released, and a high release of the drug was found at the higher pH of 7.4. Sol–gel analysis was performed to analyze the crosslinked and uncrosslinked part of the hydrogels, and results showed a rise in gel fraction as the composition of SA, AMPS and MBA increased while the sol fraction decreased and vice versa. This work demonstrated a potential for sustained delivery of diclofenac sodium by employing various concentration of SA, AMPS and MBA.


Materials ◽  
2019 ◽  
Vol 12 (21) ◽  
pp. 3634 ◽  
Author(s):  
Luciano C. B. Lima ◽  
Caio C. Coelho ◽  
Fabrícia C. Silva ◽  
Andréia B. Meneguin ◽  
Hernane S. Barud ◽  
...  

Inorganic matrices and biopolymers have been widely used in pharmaceutical fields. They show properties such as biocompatibility, incorporation capacity, and controlled drug release, which can become more attractive if they are combined to form hybrid materials. This work proposes the synthesis of new drug delivery systems (DDS) based on magnesium phyllosilicate (Talc) obtained by the sol–gel route method, the biopolymer chitosan (Ch), and the inorganic-organic hybrid formed between this matrix (Talc + Ch), obtained using glutaraldehyde as a crosslink agent, and to study their incorporation/release capacity of amiloride as a model drug. The systems were characterized by X-ray diffraction (XRD), Therma analysis TG/DTG, and Fourier-transform infrared spectroscopy (FTIR) that supported the DDS’s formation. The hybrid showed a better drug incorporation capacity compared to the precursors, with a loading of 55.74, 49.53, and 4.71 mg g−1 for Talc + Ch, Talc, and Ch, respectively. The release assays were performed on a Hanson Research SR-8 Plus dissolver using apparatus I (basket), set to guarantee the sink conditions. The in vitro release tests showed a prolongation of the release rates of this drug for at least 4 h. This result proposes that the systems implies the slow and gradual release of the active substance, favoring the maintenance of the plasma concentration within a therapeutic window.


2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Hong-Li Yu ◽  
Zhan-Qin Feng ◽  
Jing-Jing Zhang ◽  
Yong-Hong Wang ◽  
De-Jun Ding ◽  
...  

Proanthocyanidin (PC) has attracted wide attention on cosmetics and pharmaceutical due to its antioxidant, anticancer, antimicrobial, antiangiogenic, and anti-inflammatory activities. However, PC applications are limited because of its sensitivity to thermal treatment, light, and oxidation and the poor absorption in the gastrointestinal tract. Thus, a novel dosage form of PC needs to be designed to improve its stability and bioavailability for drug delivery. The objective of this study is to fabricate proanthocyanidins/chitosan/lecithin (PC/CTS/LEC) microspheres and investigate various characteristics. In the current study, PC/CTS/LEC microspheres were prepared by spray-drying technology. The yield (61.68%), encapsulation efficiency (68.19%), and drug loading capacity (17.05%) were found in the results. The scanning electron microscope demonstrated that the microspheres were spherical in shape with wrinkled surfaces. DSC study displayed that the microspheres stability was greatly improved when comparing with bare PC. The in vitro release study showed that the 76.92% of PC was released from microspheres within 48 h. The moisture contents of microspheres ranged from 8% to 13%. The swelling rate and tapped density of microspheres were elevated with increasing the concentration of chitosan in the formulations. The moisture uptake of microspheres was saturated at 40°C/RH75% within 12 h. Our results indicated that the stability of PC/CTS/LEC microspheres was enhanced, and it is a promising carrier for sustained drug delivery system.


Author(s):  
Mashkura Ashrafi ◽  
Jakir Ahmed Chowdhury ◽  
Md Selim Reza

Capsules of different formulations were prepared by using a hydrophilic polymer, xanthan gum and a filler Ludipress. Metformin hydrochloride, which is an anti-diabetic agent, was used as a model drug here with the aim to formulate sustained release capsules. In the first 6 formulations, metformin hydrochloride and xanthan gum were used in different ratio. Later, Ludipress was added to the formulations in a percentage of 8% to 41%. The total procedure was carried out by physical mixing of the ingredients and filling in capsule shells of size ‘1’. As metformin hydrochloride is a highly water soluble drug, the dissolution test was done in 250 ml distilled water in a thermal shaker (Memmert) with a shaking speed of 50 rpm at 370C &plusmn 0.50C for 6 hours. After the dissolution, the data were treated with different kinetic models. The results found from the graphs and data show that the formulations follow the Higuchian release pattern as they showed correlation coefficients greater than 0.99 and the sustaining effect of the formulations was very high when the xanthan gum was used in a very high ratio with the drug. It was also investigated that the Ludipress extended the sustaining effect of the formulation to some extent. But after a certain period, Ludipress did not show any significant effect as the pores made by the xanthan gum network were already blocked. It is found here that when the metformin hydrochloride and the xanthan gum ratio was 1:1, showed a high percentage of drug release, i.e. 91.80% of drug was released after 6 hours. But With a xanthan gum and metformin hydrochloride ratio of 6:1, a very slow release of the drug was obtained. Only 66.68% of the drug was released after 6 hours. The percent loading in this case was 14%. Again, when Ludipress was used in high ratio, it was found to retard the release rate more prominently. Key words: Metformin Hydrochloride, Xanthan Gum, Controlled release capsule Dhaka Univ. J. Pharm. Sci. Vol.4(1) 2005 The full text is of this article is available at the Dhaka Univ. J. Pharm. Sci. website


Author(s):  
Sahil Kumar ◽  
Bandna Sharma ◽  
Tilak R. Bhardwaj ◽  
Rajesh K. Singh

Aims: In the present study, polymer-drug conjugates were synthesized based on azo-bond cleavage drug delivery approach for targeting erlotinib as anticancer drug specifically to the colon for the proficient treatment of colon cancer. Background: Colon cancer (CC) is the third commonly detected tumor worldwide and it make up about 10 % of all cases of cancers. Most of the chemotherapeutic drugs available for treating colon cancer are not only toxic to cancerous cells but also to the normal healthy cells. Among the various approaches to get rid of the adverse effects of anticancer agents, prodrugs are one of the most imperative approaches. Objective: The objective of the study is to chemically modify the erlotinib drug through azo-bond linkage and suitable spacer which will be finally linked to polymeric backbone to give desired polymer linked prodrug. The azo reductase enzyme present in colon is supposed to cleave the azo-bond specifically and augment the drug release at the colon. Methods: The synthesized conjugates were characterized by IR and 1H-NMR spectroscopy. The cleavage of aromatic azobond resulted in a potential colon-specific liberation of drug from conjugate studied in rat fecal contents. In vitro release profiles of polyphosphazene-linked conjugates of erlotinib have been studied at pH 1.2, pH 6.8 and pH 7.4. The stability study was designed to exhibit that free drug was released proficiently and unmodified from polyphosphazene-erlotinib conjugates having aromatic azo-bond in artificial colon conditions. Results: The synthesized conjugates were demonstrated to be stable in simulated upper gastro-intestinal tract conditions. The drug release kinetics shows that all the polymer-drug conjugates of erlotinib follow zero-order release kinetics which indicates that the drug release from the polymeric backbone is independent of its concentration. Kinetic study of conjugates with slope (n) shows the anomalous type of release with an exponent (n) > 0.89 indicating a super case II type of release. Conclusion: These studies indicate that polyphosphazene linked drug conjugates of erlotinib could be the promising candidates for the site-specific treatment of colon cancer with least detrimental side-effects.


2009 ◽  
Vol 25 (2) ◽  
pp. 161-177 ◽  
Author(s):  
Bhavesh D. Kevadiya ◽  
Ghanshyam V. Joshi ◽  
Hasmukh A. Patel ◽  
Pravin G. Ingole ◽  
Haresh M. Mody ◽  
...  

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