scholarly journals Drug-Eluting Biodegradable Implants for the Sustained Release of Bisphosphonates

Polymers ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 2930
Author(s):  
Cintya Dharmayanti ◽  
Todd A. Gillam ◽  
Desmond B. Williams ◽  
Anton Blencowe
Keyword(s):  
Drug Release ◽  
Release Profile ◽  
Polymer Chains ◽  
Poly Lactic Acid ◽  
Initial Surface ◽  
Sustained Drug Release ◽  
Drug Eluting ◽  
Release In Vitro ◽  
Poor Absorption

Despite being one of the first-line treatments for osteoporosis, the bisphosphonate drug class exhibits an extremely low oral bioavailability (<1%) due to poor absorption from the gastrointestinal tract. To overcome this, and to explore the potential for sustained drug release, bioerodible poly(lactic acid) (PLA) and poly(D,L-lactide-co-glycolide) (PLGA) implants loaded with the bisphosphonate alendronate sodium (ALN) were prepared via hot-melt extrusion. The rate of drug release in vitro was modulated by tailoring the ratio of lactide to glycolide in the polymer and by altering the ALN-loading of the implants. All investigated implants exhibited sustained ALN release in vitro between 25 to 130 days, where implants of greater glycolide composition and higher ALN-loadings released ALN more rapidly. All PLGA implants demonstrated a sigmoidal release profile, characterised by an initial surface dissolution phase, followed by a period of zero-order drug diffusion, then relaxation or erosion of the polymer chains that caused accelerated release over the subsequent days. Contrastingly, the PLA implants demonstrated a logarithmic release profile, characterised by a gradual decrease in ALN release over time.

scholarly journals Numerical prediction of drug release from polyurethane samples combining kinetic model developed by experimental data

2021 ◽  
Vol 321 ◽  
pp. 03012
Author(s):  
Jianfei Song ◽  
Navideh Abbasnezhad ◽  
Mathieu Specklin ◽  
Mohammadali Shirinbayan ◽  
Smaine Kouidri ◽  
...  
Keyword(s):  
Experimental Data ◽  
Drug Release ◽  
Release Profile ◽  
Drug Release Profile ◽  
Flow Rates ◽  
Drug Concentrations ◽  
Calculation Results ◽  
Drug Eluting ◽  
Initial Drug

With the aim of optimizing Drug Eluting Stents (DES), particular attention has been laid on computational methods of controlling the drug release profile among researchers. Consequently, various models and simulations are available in the literature. Nevertheless, validations based on biorelevant in-vitro trials are lacking. In the present study, a comparison of drug release from polyurethane samples between calculated results and experimental-data has been carried out. The calculation results are from a numerical simulation and a newly established mathematical model for reproducing the liberation kinetic. Different fluid flow rates and initial drug concentrations in polymer have been taken into account.

scholarly journals A Tailored Thermosensitive PLGA-PEG-PLGA/Emulsomes Composite for Enhanced Oxcarbazepine Brain Delivery via the Nasal Route

Pharmaceutics ◽  
2018 ◽  
Vol 10 (4) ◽  
pp. 217 ◽  
Author(s):  
Ghada El-Zaafarany ◽  
Mahmoud Soliman ◽  
Samar Mansour ◽  
Marco Cespi ◽  
Giovanni Palmieri ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Drug Release ◽  
Glycolic Acid ◽  
Histopathological Examination ◽  
Nasal Administration ◽  
Poly Lactic Acid ◽  
Saline Control ◽  
Pharmacokinetic Studies ◽  
Sustained Drug Release

The use of nanocarrier delivery systems for direct nose to brain drug delivery shows promise for achieving increased brain drug levels as compared to simple solution systems. An example of such nanocarriers is emulsomes formed from lipid cores surrounded and stabilised by a corona of phospholipids (PC) and a coating of Tween 80, which combines the properties of both liposomes and emulsions. Oxcarbazepine (OX), an antiepileptic drug, was entrapped in emulsomes and then localized in a poly(lactic acid-co-glycolic acid)-poly(ethylene glycol)-poly(lactic acid-co-glycolic acid) (PLGA-PEG-PLGA) triblock copolymer thermogel. The incorporation of OX emulsomes in thermogels retarded drug release and increased its residence time (MRT) in rats. The OX-emulsome and the OX-emulsome-thermogel formulations showed in vitro sustained drug release of 81.1 and 53.5%, respectively, over a period of 24 h. The pharmacokinetic studies in rats showed transport of OX to the systemic circulation after nasal administration with a higher uptake in the brain tissue in case of OX-emulsomes and highest MRT for OX-emulsomal-thermogels as compared to the IN OX-emulsomes, OX-solution and Trileptal® suspension. Histopathological examination of nasal tissues showed a mild vascular congestion and moderate inflammatory changes around congested vessels compared to saline control, but lower toxic effect than that reported in case of the drug solution.

scholarly journals High-amylose carboxymethyl starch matrices for oral sustained drug-release: In vitro and in vivo evaluation

2007 ◽  
Vol 65 (3) ◽  
pp. 371-378 ◽  
Author(s):  
T. Nabais ◽  
F. Brouillet ◽  
S. Kyriacos ◽  
M. Mroueh ◽  
P. Amores da Silva ◽  
...  
Keyword(s):  
Drug Release ◽  
Sustained Drug Release ◽  
In Vivo Evaluation ◽  
Carboxymethyl Starch ◽  
Release In Vitro ◽  
High Amylose

Synthesis, Characterization and in-vitro drug release studies of a macromolecular prodrug of Didanosine.

2010 ◽  
Vol 2 (2) ◽  
Author(s):  
Neeraj Agrawal ◽  
M.J. Chandrasekar ◽  
U.V. Sara ◽  
Rohini A.
Keyword(s):  
Drug Release ◽  
Drug Level ◽  
Drug Release Profile ◽  
Sustained Drug Release ◽  
In Vitro Drug Release ◽  
Alkaline Environment ◽  
Stomach Acid ◽  
Release Studies ◽  
Macromolecular Prodrug

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.

Formulation and Evaluation of Chitosan-Polyaniline Nanocomposites for Controlled Release of Anticancer Drug Doxorubicin

2018 ◽  
Vol 8 (2) ◽  
Author(s):  
Dillip Kumar Behera ◽  
Kampal Mishra ◽  
Padmolochan Nayak
Keyword(s):  
Tensile Strength ◽  
Drug Release ◽  
Nanocomposite Films ◽  
Casting Method ◽  
Sustained Drug Release ◽  
In Vitro Drug Release ◽  
Clay Particles ◽  
Solution Casting Method ◽  
Nanoclay Content

In this present work, chitosan (CS) crosslink with polyaniline (PANI) with montmorilonite (MMT) called as (CSPANI/MMT) and CS crosslink with PANI without MMT called as (CS-PANI) were prepared by employing the solution casting method. Further the formation of nanocomposites CS-PANI/MMT and CS-PANI were investigated using XRD, FTIR, SEM and tensile strength. Water uptake and swelling ratio of the CS-PANI and CS-PANI/MMT were found to decrease with increase in concentration of clay. Mechanical properties of the CS-PANI and CS-PANI/MMT were assessed in terms of tensile strength and extensibility using texture analyzer. Increase in tensile strength and reduction in extensibility was reported with increase in the nanoclay content. In vitro drug release study on CS-PANI and CS-PANI/MMT indicated pronounced sustained release of doxorubicin by the incorporation of clay particles in the CS polymer matrix. Overall CSPANI/MMT nanocomposite films exhibited improved mechanical and sustained drug release properties than CS-PANI.

Development and Optimization of Sustained Release Moxifloxacin Hydrochloride Loaded Nanoemulsion for Ophthalmic Drug Delivery: A 32 Factorial Design Approach

2020 ◽  
Vol 12 ◽  
Author(s):  
Sagar R. Pardeshi ◽  
Harshal A. Mistari ◽  
Rakhi S. Jain ◽  
Pankaj R. Pardeshi ◽  
Rahul L. Rajput ◽  
...  
Keyword(s):  
Drug Release ◽  
Sustained Release ◽  
Factorial Design ◽  
Water Solubility ◽  
Tween 80 ◽  
Drug Release Profile ◽  
Sustained Drug Release ◽  
Bacterial Conjunctivitis ◽  
Promising Alternative

Background: Moxifloxacin is a BCS class I drug used in the treatment of bacterial conjunctivitis and keratitis. Despite its high water solubility, it possesses limited bioavailability due to anatomical and physiological constraints associated with the eyes which required multiple administrations to achieve a therapeutic effect. Objective: In order to prolong drug release and to improve antibacterial efficacy for the treatment of bacterial keratitis and conjunctivitis, moxifloxacin loaded nanoemulsion was developed. Methods: The concentration of oil (oleic acid), surfactant (tween 80), and cosurfactant (propylene glycol) were optimized by employing a 3-level 2-factorial design of experiment for the development of nanoemulsion. The developed nanoemulsion was characterized by particle size distribution, viscosity, refractive index, pH, drug content and release, transmission electron microscopy (TEM), and antibacterial study. The compatibility of the drug with the excipients was accessed by Fourier transform infrared spectroscopy (FTIR). Result: The average globule size was found to be 198.20 nm. The TEM study reveals the globules were nearly spherical and are well distributed. In vitro drug release profile for nanoemulsion shown sustained drug release (60.12% at the end of 6 h) compared to drug solution, where complete drug released within 2 h. The antibacterial effectiveness of the drug-loaded nanoemulsion was improved against S. aureus compared with the marketed formulation. Conclusion: The formulated sustained release nanoemulsion could be a promising alternative to eye drop with improved patient compliance by minimizing dosing frequency with improved antibacterial activity.

scholarly journals Comparative Analysis of Morphological and Release Profiles in Ocular Implants of Acetazolamide Prepared by Electrospinning

Pharmaceutics ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 260
Author(s):  
Mariana Morais ◽  
Patrícia Coimbra ◽  
Maria Eugénia Pina
Keyword(s):  
Drug Release ◽  
In Vitro Release ◽  
Morbidity Rate ◽  
Coating Film ◽  
Sustained Drug Release ◽  
Coated Implant ◽  
Poly Ethylene ◽  
Coaxial Fibers ◽  
Release Profiles

The visual impairment that often leads to blindness causes a higher morbidity rate. The goal of this work is to create a novel biodegradable polymeric implant obtained from coaxial fibers containing the dispersed drug—acetazolamide—in order to achieve sustained drug release and increase patient compliance, which is of the highest importance. Firstly, during this work, uncoated implants were produced by electrospinning, and rolled in the shape of small cylinders that were composed of uniaxial and coaxial fibers with immobilized drug inside. The fibers were composed by PCL (poly ε-caprolactone) and Lutrol F127 (poly (oxyethylene-b-oxypropylene-b-oxyethylene)). The prepared implants exhibited a fast rate of drug release, which led to the preparation of new implants incorporating the same formulation but with an additional coating film prepared by solvent casting and comprising PCL and Lutrol F127 or PCL and Luwax EVA 3 ((poly (ethylene-co-vinyl acetate)). Implants were characterized and in vitro release profiles of acetazolamide were obtained in phosphate buffered saline (PBS) at 37 °C. The release profile of the acetazolamide from coated implant containing Luwax EVA 3 is considerably slower than what was observed in case of coated implants containing Lutrol F127, allowing a sustained release and an innovation relatively to other ocular drug delivery systems.

Formulation development of folic acid conjugated PLGA nanoparticles for improved cytotoxicity of Caffeic acid phenethyl ester

2021 ◽  
Vol 09 ◽  
Author(s):  
Harshad S Kapare ◽  
Sathiyanarayanan L ◽  
Arulmozhi S ◽  
Kakasaheb Mahadik
Keyword(s):  
Folic Acid ◽  
Drug Release ◽  
Caffeic Acid ◽  
Caffeic Acid Phenethyl Ester ◽  
Therapeutic Effects ◽  
Formulation Development ◽  
Sustained Drug Release ◽  
Active Constituent

Background: Honey bee propolis is one of the natural product reported in various traditional systems of medicines including Ayurveda. Caffeic acid phenethyl ester (CAPE) is an active constituent of propolis which is well known for its anticancer potential. The therapeutic effects of CAPE are restricted owing to its less aqueous solubility and low bioavailability. Objective: In this study CAPE loaded folic acid conjugated nanoparticle system (CLFPN) was investigated to enhance solubility, achieve sustained drug release and improved cytotoxicity of CAPE. Methods: Formulation development, characterization and optimization were carried out by design of experiment approach. In vitro and in vivo cytotoxicity study was carried out for optimized formulations. Results: Developed nanoparticles showed particle size and encapsulation efficiency of 170 ± 2 - 195 ± 3 nm and 75.66 ± 1.52 - 78.80 ± 1.25 % respectively. Optimized formulation CLFPN showed sustained drug release over a period of 42 h. GI50 concentration was decreased by 46.09% for formulation as compared to CAPE in MCF-7 cells indicating targeting effect of CLFPN. An improved in vitro cytotoxic effect was reflected in in-vivo Daltons Ascites Lymphoma model by reducing tumor cells count. Conclusion: The desired nanoparticle characteristic with improved in vivo and in vitro cytotoxicity was shown by developed formulation. Thus it can be further investigated for biomedical applications.

scholarly journals DESIGN AND IN VITRO/IN VIVO EVALUATION OF EXTENDED RELEASE MATRIX TABLETS OF NATEGLINIDE

2018 ◽  
Vol 7 (6) ◽  
Author(s):  
Mohini Sihare ◽  
Rajendra Chouksey
Keyword(s):  
Drug Release ◽  
Release Kinetics ◽  
In Vitro Release ◽  
Release Profile ◽  
Matrix Tablets ◽  
In Vivo Studies ◽  
Release Mechanism ◽  
In Vivo Evaluation

Aim: Nateglinide is a quick acting anti-diabetic medication whose potent activity lasts for a short duration. One of the dangerous side effects of nateglinide administration is rapid hypoglycemia, a condition that needs to be monitored carefully to prevent unnecessary fatalities. The aim of the study was to develop a longer lasting and slower releasing formulation of nateglinide that could be administered just once daily. Methods: Matrix tablets of nateglinide were prepared in combination with the polymers hydroxypropylmethylcellulose (HPMC), eudragits, ethyl cellulose and polyethylene oxide and the formulated drug release patterns were evaluated using in vitro and in vivo studies. Conclusion: Of the seventeen formulated matrix tablets tested, only one formulation labelled HA-2 that contained 15% HPMC K4M demonstrated release profile we had aimed for. Further, swelling studies and scanning electron microscopic analysis confirmed the drug release mechanism of HA-2. The optimized formulation HA-2 was found to be stable at accelerated storage conditions for 3 months with respect to drug content and physical appearance. Mathematical analysis of the release kinetics of HA-2 indicated a coupling of diffusion and erosion mechanisms. In-vitro release studies and pharmacokinetic in vivo studies of HA-2 in rabbits confirmed the sustained drug release profile we had aimed for. Keywords: Hydroxypropylmethylcellulose, Matrix tablets, Nateglinide, Sustained release

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