scholarly journals Synthesis and Characterization of Ionic Graft Copolymers: Introduction and In Vitro Release of Antibacterial Drug by Anion Exchange

Polymers ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 2159
Author(s):  
Katarzyna Niesyto ◽  
Dorota Neugebauer
Keyword(s):  
Bacterial Infections ◽  
Graft Copolymers ◽  
In Vitro Release ◽  
Water Soluble ◽  
Antibacterial Drug ◽  
Water Contact ◽  
Drug Conjugates ◽  
Self Assembling ◽  
Grafting From

Amphiphilic graft copolymers based on [2-(methacryloyloxy)ethyl]trimethyl- ammonium chloride (TMAMA) were obtained for the delivery of pharmaceutical ionic drugs, such as p-aminosalicylate (PAS) and clavunate (CLV) anions. The side chains were attached by grafting from a multifunctional macroinitiator via atom transfer radical polymerization (ATRP) to get polymers with different grafting degrees and ionic content. The self-assembling ability, confirmed by determining the critical micelle concentration (CMC) through interfacial tension (IFT) with the use of goniometry, was reduced after ion exchange (CMC twice higher than for chloride anions contained copolymers 0.005–0.026 mg/mL). Similarly, the hydrophilicity level (adjusted by the content of ionic fraction) evaluated by the water contact angle (WCA) of the polymer film surfaces was decreased with the increase of trimethylammonium units (68°–44°) and after introduction of pharmaceutical anions. The exchange of Cl− onto PAS− and CLV− in the polymer matrix was yielded at 31%–64% and 79%–100%, respectively. The exchange onto phosphate anions to release the drug was carried out (PAS: 20%–42%, 3.1–8.8 μg/mL; CLV: 25%–73%, 11–31 μg/mL from 1 mg of drug conjugates). Because of the bacteriostatic activity of PAS and the support of the action of the antibiotics by CLV, the designed water-soluble systems could be alternatives for the treatment of bacterial infections, including pneumonia and tuberculosis.

Controlled Release of Metformin Hydrochloride I. In vitro Release from Physical Mixture Containing Xanthan Gum as Hydrophilic Rate Retarding Polymer

1970 ◽  
Vol 4 (1) ◽  
Author(s):  
Mashkura Ashrafi ◽  
Jakir Ahmed Chowdhury ◽  
Md Selim Reza
Keyword(s):  
Controlled Release ◽  
Xanthan Gum ◽  
In Vitro Release ◽  
Correlation Coefficients ◽  
High Ratio ◽  
Water Soluble ◽  
Metformin Hydrochloride ◽  
Model Drug ◽  
Very High

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

Fenofibrate Solid Dispersion for Improving Oral Bioavailability: Preparation, and Characterization and in vivo Evaluation

2020 ◽  
Vol 13 (5) ◽  
pp. 5102-5109
Author(s):  
Venu Madhav K ◽  
Somnath De ◽  
Chandra Shekar Bonagiri ◽  
Sridhar Babu Gummadi
Keyword(s):  
Oral Bioavailability ◽  
Oral Delivery ◽  
Solid Dispersions ◽  
In Vitro Release ◽  
Aqueous Solubility ◽  
Water Soluble ◽  
Scanning Calorimetry ◽  
In Vivo Evaluation

Fenofibrate (FN) is used in the treatment of hypercholesterolemia. It shows poor dissolution and poor oral bioavailability after oral administration due to high liphophilicity and low aqueous solubility. Hence, solid dispersions (SDs) of FN (FN-SDs) were develop that might enhance the dissolution and subsequently oral bioavailability. FN-SDs were prepared by solvent casting method using different carriers (PEG 4000, PEG 6000, β cyclodextrin and HP β cyclodextrin) in different proportions (0.25%, 0.5%, 0.75% and 1% w/v). FN-SDs were evaluated solubility, assay and in vitro release studies for the optimization of SD formulation. Differential scanning calorimetry (DSC), powder X-ray diffraction (PXRD) and scanning electron microscopy (SEM) analysis was performed for crystalline and morphology analysis, respectively. Further, optimized FN-SD formulation evaluated for pharmacokinetic performance in Wistar rats, in vivo in comparison with FN suspension.  From the results, FN-SD3 and FN-SD6 have showed 102.9 ±1.3% and 105.5±3.1% drug release, respectively in 2 h. DSC and PXRD studies revealed that conversion of crystalline to amorphous nature of FN from FT-SD formulation. SEM studies revealed the change in the orientation of FN when incorporated in SDs. The oral bioavailability FN-SD3 and FN-SD6 formulations exhibited 2.5-folds and 3.1-folds improvement when compared to FN suspension as control. Overall, SD of FN could be considered as an alternative dosage form for the enhancement of oral delivery of poorly water-soluble FN.

Solubility Enhancement of Poorly Water-Soluble Antifungal Drug Acyclovir by Nanocrystal Formulation Approach

2018 ◽  
Vol 11 (2) ◽  
pp. 4036-4042
Author(s):  
Prakash Goudanavar ◽  
Ankit Acharya ◽  
Vinay C.H
Keyword(s):  
Chemical Interaction ◽  
Research Work ◽  
Antiviral Drug ◽  
In Vitro Release ◽  
Oral Route ◽  
Water Soluble ◽  
Precipitation Method ◽  
Dsc Studies ◽  
Ft Ir

Administration of an antiviral drug, acyclovir via the oral route leads to low and variable bioavailability (15-30%). Therefore, this research work was aimed to enhance bioavailability of acyclovir by nanocrystallization technique. The drug nanocrystals were prepared by anti-solvent precipitation method in which different stabilizers were used. The formed nanocrystals are subjected to biopharmaceutical characterization including solubility, particle size and in-vitro release. SEM studies showed nano-crystals were crystalline nature with sharp peaks. The formulated drug nanocrystals were found to be in the range of 600-900nm and formulations NC7 and NC8 showed marked improvement in dissolution velocity when compared to pure drug, thus providing greater bioavailability. FT-IR and DSC studies revealed the absence of any chemical interaction between drug and polymers used. 

Design, Synthesis and Studies on Novel Polymeric Prodrugs of Erlotinib for Colon Drug Delivery

2020 ◽  
Vol 20 ◽  
Author(s):  
Sahil Kumar ◽  
Bandna Sharma ◽  
Tilak R. Bhardwaj ◽  
Rajesh K. Singh
Keyword(s):  
Drug Delivery ◽  
Colon Cancer ◽  
Drug Release ◽  
Anticancer Agents ◽  
Release Kinetics ◽  
In Vitro Release ◽  
Specific Treatment ◽  
Drug Conjugates ◽  
Polymer Drug Conjugates

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.

Minocycline hydrochloride loaded mPEG-PCLA membranes: Preparation and in vitro evaluation for periodontitis therapy

2021 ◽  
pp. 088391152199279
Author(s):  
Ningtao Wang ◽  
Zhengmei Huang ◽  
Shenchun Wang ◽  
Meidong Lang ◽  
Xiuyin Zhang
Keyword(s):  
Drug Delivery ◽  
Drug Loading ◽  
Membrane Surface ◽  
Local Treatment ◽  
In Vitro Release ◽  
Periodontal Pathogen ◽  
Antibacterial Drug ◽  
Periodontal Ligament Fibroblasts ◽  
Minocycline Hydrochloride

This study was aimed at alleviating shortcomings in the treatment of periodontitis by preparation of a biopolymer membrane loaded with minocycline hydrochloride (MH) inserted into periodontal pockets to treat infections. Monomethoxy-poly (ethylene glycol)-poly (ε-caprolactone-co-L-lactide) (mPEG-PCLA) is a biocompatible and biodegradable amphiphilic block copolymer. It, therefore, has attracted considerable attention in drug delivery systems and periodontal treatment. We chose it as a membrane material for MH-drug loading. The MH-loaded membranes were prepared by the solvent casting technique with the content of 5, 8 and 10 wt.%, respectively. Fourier transform infrared spectra (FTIR) revealed no interaction between MH and polymer. The drug-loaded membrane surface morphology was investigated by scanning electron microscopy (SEM). In vitro release studies showed that the initial drug release exceeded 40% within 24 h, followed by a sustained release for up to 2 weeks, which would enable the therapeutic level to maintain over a longer time. The antibacterial activity studies in vitro demonstrated a positive effect on the periodontal pathogen. MH drug-loaded membranes have no adverse effect on the growth of periodontal ligament fibroblasts in the MTT test. The study suggests that mPEG-PCLA membranes containing MH are a potential antibacterial drug delivery system for local treatment of periodontitis.

scholarly journals Novel Gliclazide Electrosprayed Nano-Solid Dispersions: Physicochemical Characterization and Dissolution Evaluation

2019 ◽  
Vol 9 (2) ◽  
pp. 231-240
Author(s):  
Khosro Adibkia ◽  
Solmaz Ghajar ◽  
Karim Osouli-Bostanabad ◽  
Niloufar Balaei ◽  
Shahram Emami ◽  
...  
Keyword(s):  
Drug Release ◽  
Solid Dispersions ◽  
In Vitro Release ◽  
Physicochemical Characterization ◽  
Amorphous State ◽  
Water Soluble ◽  
Fickian Diffusion ◽  
Release Mechanism ◽  
Peg 6000

Purpose: In the current study, electrospraying was directed as a novel alternative approach to improve the physicochemical attributes of gliclazide (GLC), as a poorly water-soluble drug, by creating nanocrystalline/amorphous solid dispersions (ESSs). Methods: ESSs were formulated using Eudragit® RS100 and polyethylene glycol (PEG) 6000 as polymeric carriers at various drug: polymer ratios (i.e. 1:5 and 1:10) with different total solution concentrations of 10, 15, and 20% w/v. Morphological, physicochemical, and in-vitro release characteristics of the developed formulations were assessed. Furthermore, GLC dissolution behaviors from ESSs were fitted to various models in order to realize the drug release mechanism. Results: Field emission scanning electron microscopy analyses revealed that the size and morphology of the ESSs were affected by the drug: polymer ratios and solution concentrations. The polymer ratio augmentation led to increase in the particle size while the solution concentration enhancement yielded in a fiber establishment. Differential scanning calorimetry and powder X-ray diffraction investigations demonstrated that the ESSs were present in an amorphous state. Furthermore, the in vitro drug release studies depicted that the samples prepared employing PEG 6000 as carrier enhanced the dissolution rate and the model that appropriately fitted the release behavior of ESSs was Weibull model, where demonstrating a Fickian diffusion as the leading release mechanism. Fourier-transform infrared spectroscopy results showed a probability of complexation or hydrogen bonding, development between GLC and the polymers in the solid state. Conclusion: Hence the electrospraying system avails the both nanosizing and amorphization advantages, therefore, it can be efficiently applied to formulating of ESSs of BCS Class II drugs.

scholarly journals Development and Characterization of Glimepiride Novel Solid Nanodispersion for Improving Its Oral Bioavailability

2020 ◽  
Vol 88 (4) ◽  
pp. 52
Author(s):  
Mona Qushawy ◽  
Ali Nasr ◽  
Shady Swidan ◽  
Yasmin Mortagi
Keyword(s):  
Solid Dispersion ◽  
Drug Carrier ◽  
In Vitro Release ◽  
Water Soluble ◽  
Production Yield ◽  
Scanning Calorimetry ◽  
Differential Scanning Calorimetry Study ◽  
Drug Content ◽  
Vitro Release

Glimepiride is an antidiabetic drug which is one of the third generation sulfonylureas. It belongs to class II, according to the BCS (Biopharmaceutical Classification System), which is characterized by low solubility and high permeability. The aim of this work was to formulate glimepiride as solid dispersion using water-soluble carriers to enhance its aqueous solubility and thus enhance its bioavailability. Nine formulations of glimepiride solid dispersion were prepared by a solvent evaporation technique using three different carriers (mannitol, polyethylene glycol 6000, and β-cyclodextrin) with three different drug carrier ratio (1:1, 1:3, and 1:6). Formulation variables were optimized using 32 full factorial design. The prepared formulations were evaluated for production yield, drug content, micromeritic properties, thermal analysis, in-vitro release, and in-vivo hypoglycemic effect. All prepared formulations showed high production yield ranged from 98.4 ± 2.8 to 99.8 ± 2.2% and high drug content in the range of 97.2 ± 3.2 to 99.6 ± 2.1%. The micromeritic properties revealed that all prepared glimepiride formulations showed good flowability. The differential scanning calorimetry study revealed the presence of the drug in the more soluble amorphous form. In accordance with the results of in vitro release study, it was found that the solubility of glimepiride was increased by increasing the drug carrier ratio, compared with the pure form of the drug. It was found that F9 showed a high and rapid reduction in blood glucose levels in diabetic rats, which indicated the success of a solid dispersion technique in improving the solubility and hence the bioavailability of glimepiride.

scholarly journals Dissolution Enhancement of Rosuvastatin Calcium by Liquisolid Compact Technique

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
V. J. Kapure ◽  
V. V. Pande ◽  
P. K. Deshmukh
Keyword(s):  
Drug Release ◽  
In Vitro Release ◽  
Water Soluble ◽  
Dissolution Enhancement ◽  
Content Uniformity ◽  
Scanning Calorimetry ◽  
Weight Variation ◽  
Liquisolid Compacts ◽  
Rosuvastatin Calcium

In present investigation liquisolid compact technique is investigated as a tool for enhanced dissolution of poorly water-soluble drug Rosuvastatin calcium (RVT). The model drug RVT, a HMG-Co A reductase inhibitor was formulated in form of directly compressed tablets and liquisolid compacts; and studied for in-vitro release characteristics at different dissolution conditions. In this technique, liquid medications of water insoluble drugs in non-volatile liquid vehicles can be converted into acceptably flowing and compressible powders. Formulated systems were assessed for precompression parameters like flow properties of liquisolid system, Fourior transform infra red spectra (FTIR) analysis, X-ray powder diffraction (XRPD), differential scanning calorimetry (DSC), and post compression parameters like content uniformity, weight variation, hardness and friability, disintegration test, wetting time, in vitro dissolution studies, effect of dissolution volume on drug release rate, and estimation of fraction of molecularly dispersed drug in liquid medication. As liquisolid compacts demonstrated significantly higher drug release rates, we lead to conclusion that it could be a promising strategy in improving the dissolution of poor water soluble drugs and formulating immediate release solid dosage forms.

Polymer–drug conjugates: towards a novel approach for the treatment of endrocine-related cancer

2005 ◽  
Vol 12 (Supplement_1) ◽  
pp. S189-S199 ◽  
Author(s):  
R Duncan ◽  
M J Vicent ◽  
F Greco ◽  
R I Nicholson
Keyword(s):  
Clinical Trials ◽  
Anticancer Agents ◽  
Antitumour Activity ◽  
Metastatic Cancer ◽  
Clinical Results ◽  
Water Soluble ◽  
Current Status ◽  
Hpma Copolymer ◽  
Drug Conjugates

The last decade has seen successful clinical application of polymer–protein conjugates (e.g. Oncaspar, Neulasta) and promising results in clinical trials with polymer–anticancer drug conjugates. This, together with the realisation that nanomedicines may play an important future role in cancer diagnosis and treatment, has increased interest in this emerging field. More than 10 anticancer conjugates have now entered clinical development. Phase I/II clinical trials involving N-(2-hydroxypropyl)methacrylamide (HPMA) copolymer-doxorubicin (PK1; FCE28068) showed a four- to fivefold reduction in anthracycline-related toxicity, and, despite cumulative doses up to 1680 mg/m2 (doxorubicin equivalent), no cardiotoxicity was observed. Antitumour activity in chemotherapy-resistant/refractory patients (including breast cancer) was also seen at doxorubicin doses of 80–320 mg/m2, consistent with tumour targeting by the enhanced permeability (EPR) effect. Hints, preclinical and clinical, that polymer anthracycline conjugation can bypass multidrug resistance (MDR) reinforce our hope that polymer drugs will prove useful in improving treatment of endocrine-related cancers. These promising early clinical results open the possibility of using the water-soluble polymers as platforms for delivery of a cocktail of pendant drugs. In particular, we have recently described the first conjugates to combine endocrine therapy and chemotherapy. Their markedly enhanced in vitro activity encourages further development of such novel, polymer-based combination therapies. This review briefly describes the current status of polymer therapeutics as anticancer agents, and discusses the opportunities for design of second-generation, polymer-based combination therapy, including the cocktail of agents that will be needed to treat resistant metastatic cancer.

Sign in / Sign up

Export Citation Format

Share Document