scholarly journals In Vitro Evaluation of a Peptide-Mesoporous Silica Nanoparticle Drug Release System against HIV-1

Inorganics ◽  
2020 ◽  
Vol 8 (7) ◽  
pp. 42 ◽  
Author(s):  
Katharina Braun ◽  
Christina M. Stürzel ◽  
Frank Kirchhoff ◽  
Mika Lindén

It has been shown that the optimized VIR-576 derivative of the natural HIV-1 entry inhibitor targeting the viral gp41 fusion peptide is safe and effective in infected individuals. However, high doses of this peptide were required, and stability, as well as delivery, must be improved for clinical application. Here, we examined the loading and release of VIR-576 into/from mesoporous silica nanoparticles (MSNs) in vitro. We found that a moderately high peptide loading of 11.5 wt % could be achieved by adsorption from PBS buffer (pH 7.2), i.e., under mild, fully peptide-compatible conditions. The release rate of peptide into the same buffer was slow and the equilibrium concentration as indicated by the adsorption isotherm could not be reached even within 50 h at the particle concentrations studied. However, a faster release was observed at lower particle concentrations, indicating that partial particle dissolution had a positive influence on peptide release. To determine the antiviral activity of VIR-576-loaded MSNs, TZM-bl indicator cells were exposed to HIV-1 and the infection rates were followed as a function of time and VIR-576 concentration. The inhibitory activity observed for VIR-576 released from the MSNs was virtually identical to that of free VIR-576 at the 48 h time point, indicating that (a) VIR-576 was released in an active form from the MSNs, and (b) the release rate in the presence of serum proteins was clearly higher than that observed under protein-free conditions. These observations are discussed based on competitive peptide/protein adsorption, as well as potential influences of serum proteins on the dissolution-reprecipitation of silica under conditions where the total silica concentration is above the saturation level for dissolved silica. Our results highlight the need for studying drug release kinetics in the presence of serum proteins, in order to allow for a better extrapolation of in vitro data to in vivo conditions. Furthermore, due to the high peptide loadings that can be achieved using MSNs as carriers, such a formulation appears promising for local release applications. For systemic administration, however, peptides with a higher potency would be needed, due to their high molar masses limiting the drug loading in terms of moles per gram carrier.

2016 ◽  
Vol 19 (1) ◽  
pp. 58-67
Author(s):  
Paroma Arefin ◽  
Ikramul Hasan ◽  
Md Shfiqul Islam ◽  
Md Selim Reza

The present study deals with the formulation and evaluation of Fexofenadine hydrochloride (HCl) loaded sustained release microspheres by emulsion solvent evaporation method with Eudragit RL 100. The effects of percent drug loading on drug encapsulation efficiency, drug content and drug release rate were assessed. In vitro dissolution study was performed spectrophotometrically according to USP paddle method using phosphate buffer (pH 6.8) for 10 hours. The release rate of Fexofenadine HCl from the microspheres was significantly increased with the increase of drug loading. The drug release patterns were simulated in different kinetic orders such as zero order release kinetics, first order release kinetics, Higuchi release kinetics, Korsmeyer-Peppas release kinetics and Hixson-Crowell release kinetics to assess the release mechanism and Higuchi release kinetics was found to be the predominant release mechanism. Morphological changes due to different drug loading were assessed by scanning electron microscopic (SEM) technique. Differential scanning calorimetry and fourier transform infra-red (FT-IR) spectroscopy was performed to evaluate compatibility of drug with the polymer. A statistically significant variation indrug encapsulation efficiency and release rate was observed for variation in drug loading.Bangladesh Pharmaceutical Journal 19(1): 58-67, 2016


2017 ◽  
Vol 23 (3) ◽  
pp. 467-480 ◽  
Author(s):  
Satyanarayan Pattnaik ◽  
Kamla Pathak

Background: Improvement of oral bioavailability through enhancement of dissolution for poorly soluble drugs has been a very promising approach. Recently, mesoporous silica based molecular sieves have demonstrated excellent properties to enhance the dissolution velocity of poorly water-soluble drugs. Description: Current research in this area is focused on investigating the factors influencing the drug release from these carriers, the kinetics of drug release and manufacturing approaches to scale-up production for commercial manufacture. Conclusion: This comprehensive review provides an overview of different methods adopted for synthesis of mesoporous materials, influence of processing factors on properties of these materials and drug loading methods. The drug release kinetics from mesoporous silica systems, the manufacturability and stability of these formulations are reviewed. Finally, the safety and biocompatibility issues related to these silica based materials are discussed.


2020 ◽  
pp. 1-9
Author(s):  
Yunhong Wang ◽  
Rong Hu ◽  
Yanlei Guo ◽  
Weihan Qin ◽  
Xiaomei Zhang ◽  
...  

OBJECTIVE: In this study we explore the method to prepare tanshinone self-microemulsifying sustained-release microcapsules using tanshinone self-microemulsion as the core material, and chitosan and alginate as capsule materials. METHODS: The optimal preparation technology of chitosan-alginate tanshinone self-microemulsifying sustained-release microcapsules was determined by using the orthogonal design experiment and single-factor analysis. The drug loading and entrapment rate were used as evaluation indexes to assess the quality of the drug, and the in vitro release rate was used to evaluate the drug release performance. RESULTS: The best technology of chitosan-alginate tanshinone self-microemulsifying sustained-release microcapsules is as follows: the concentration of alginate is 1.5%, the ratio of tanshinone self-microemulsion volume to alginate volume to chitosan mass is 1:1:0.5 (ml: ml: g), and the best concentration of calcium chloride is 2.0%. To prepare the microcapsules using this technology, the drug loading will be 0.046%, the entrapment rate will be 80.23%, and the 24-hour in vitro cumulative release rate will be 97.4%. CONCLUSION: The release of the microcapsules conforms to the Higuchi equation and the first-order drug release model and has a good sustained-release performance.


2018 ◽  
Vol 6 (11) ◽  
pp. 61-80 ◽  
Author(s):  
Shashank Soni ◽  
Veerma Ram ◽  
Anurag Verma

In the present experimental investigation an attempt has been made to assess the utility of Crushed Puffed Rice (CPR)-High Molecular Weight Chitosan (HMWCH)-Hydroxypropyl Methylcellulose K15M (HPMC K15M) as a polymeric carrier for the sustained stomach delivery of Piroxicam (PRX). A total of nine formulations were prepared by using 3 (2) Taguchi factorial design, physically blending drug and polymer(s) followed by encapsulation into hard gelatin capsules size 1. The prepared capsules were evaluated for various performance such as weight variation, drug contents, in vitro buoyancy and drug release in 0.1 M HCl. The effect of drug loading on in vitro performance of the formulations was also determined. Crushed puffed rice (CPR) remained buoyant for up to average time span of 06 hr as an unwetted irregular mass in 0.1 M HCl. However, when combined with HMWCH or HPMC K15M or HPMC K15M + HMWCH a low -density cylindrical raft type hydrogel was formed which remained buoyant for up to 12 hr and released up to 99% drug in a sustained manner from 8 to 12 hr following zero order release kinetics. It was also observed that drug release from drug + CPR matrices followed Fickian mechanism. Combination of CPR + HMWCH or HMWCH + HPMC K15M also follows Fickian mechanism. Obtained data from the research work suggests that CPR in combination with HMWCH or HPMC K15M or HPMC has sufficient potential to be used as a carrier for stomach specific delivery of gastric irritant drug like PRX.Soni et al., International Current Pharmaceutical Journal, April 2018, 6(11): 61-80http://www.icpjonline.com/documents/Vol6Issue11/01.pdf


2018 ◽  
Vol 8 (5) ◽  
pp. 465-474
Author(s):  
S PADMA PRIYA ◽  
AN Rajalakshmi ◽  
P Ilaveni

Objective: The objective of this research work is to develop and evaluate mucoadhesive microspheres of an anti-migraine drug for sustained release. Materials and Methods:  Mucoadhesive microspheres were prepared by emulsification method using Sodium alginate (SA), polyvinyl pyrrolidone (PVP) and Chitosan in the various drug-polymer ratios of 1:1, 1:2 and 1:3. Nine  formulations were formulated and  evaluated for  possible drug polymer interactions, percentage yield, micromeritic properties, particle size, drug content, drug entrapment efficiency, drug loading, swelling index, In-vitro wash off test, in vitro  drug release, surface morphology and release kinetics. Results: The results showed that no significant drug polymer interaction in FTIR studies. Among all the formulations SF3 containing sodium alginate showed 77.18% drug release in 6hrs. Conclusion: Amongst the developed mucoadhesive microspheres, SF3 formulation containing sodium alginate exhibited slow and sustained release in a controlled manner and it is a promising formulation for sustained release of Sumatriptan succinate. Keywords: Mucoadhesive microspheres, Sodium alginate, polyvinyl pyrrolidone, Chitosan, sustained release.


Author(s):  
Koyel Kar ◽  
R. N. Pal ◽  
N. N. Bala

Objective: The major objective of the research work was to design, characterise and evaluate controlled release microspheres of ropinirole hydrochloride by using non-aqueous solvent evaporation technique to facilitate the delivery of the drug at a predetermined rate for a specific period of time.Methods: Ropinirole hydrochloride microspheres were prepared by using different low-density polymers such as eudragit RL 100, eudragit RS 100 and ethylcellulose either alone or in combination with the help of non-aqueous solvent evaporation technique. All the formulated microparticles were subjected to various evaluation parameters such as particle size analysis, micrometric properties, drug entrapment efficiency, percentage drug loading, percentage yield and in vitro drug release study. The compatibility of the drug and polymers was confirmed by physical compatibility study, fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC) and x-ray diffraction study (XRD). The formation of the most optimized batch of the microsphere (F12) was confirmed by scanning electron microscopy (SEM), DSC, FTIR, and XRD. In vitro drug release study and in vitro drug release kinetics study of the formulated microspheres were also carried out.Results: Drug-polymer compatibility studies performed with the help of FTIR and DSC indicated that there were no interactions. Results revealed that non-aqueous solvent evaporation technique was a suitable technique for the preparation of microspheres as most of the formulations were discrete, free-flowing and spherical in shape with a good yield of 55.67% to 80.09%, percentage drug loading of 35.52% to 94.50% and percentage drug entrapment efficiency of 36.24% to 95.07%. Different drug-polymer ratios, as well as the combination of polymers, played a significant role in the variation of over-all characteristics of formulations. Based on the data of various evaluation parameters such as particle size analysis, percentage drug loading, percentage drug entrapment, percentage yield, rheological studies and in vitro drug release characteristics, formulation F12 was found to fulfil the criteria of ideal controlled release drug delivery system. F12 showed controlled release till the 14th hour (97.99%) and its in vitro release kinetics was best explained by zero-order kinetics and followed Korsemeyer-Pappas model (Non-Fickian mechanism). SEM of F12 revealed the formation of spherical structures. The FTIR study of F12 confirmed the stable nature of ropinirole in the drug-loaded microspheres. DSC and XRD patterns showed that ropinirole hydrochloride was dispersed at the molecular level in the polymer matrix.Conclusion: The controlled release microparticles were successfully prepared and from this study, it was concluded that the developed microspheres of ropinirole hydrochloride can be used for controlled drug release to improve the bioavailability and patient compliance and to maintain a constant drug level in the blood target tissue by releasing the drug in zero order pattern.


Author(s):  
VENKATA RAMANA REDDY K. ◽  
NAGABHUSHANAM M. V. ◽  
PAMULA REDDY B. ◽  
RAVINDAR NAIK E.

Objective: The aim of the present work was to prepare and examine drug release of the oral controlled release microbeads using different curing agents by emulsification internal ionic gelation technique. Methods: Cross-linked alginate microbeads were prepared with different cross linking agents by using mucoadhesive properties. The formation and compatibility of microbeads were confirmed by compatibility studies. Prepared microbeads evaluated for encapsulated efficiency, micromeritic properties, drug loading, in vitro wash off studies, in vitro dissolution studies, drug release kinetics and stability studies Results: The in vitro drug release was influenced by both type of curing agents and type of polymers and no significant changes in characterization parameters was observed after 3 mo stability studies. The sustained release profile of optimized batch was found to be 99.66±0.18% in comparison to pure drug profile of 28.64±0.02% at 12 h release study. Results of both wash-off and in vitro studies suggests that batch (SF2) prepared with aluminium chloride has shown better mucoadhesive property. Drug release of optimized batch follows zero order with non fickian mechanism according to Korsmeyer-Peppas equation. Conclusion: The data suggest the use of simvastatin mucoadhesive cross linked microbeads to offer the potential for oral controlled drug delivery with improved gastric retention and capable to provide sustained drug release by using cross linking agents.


Author(s):  
Rashmi Gupta ◽  
Leena Vishwakarma ◽  
Sunil Kant Guleri ◽  
Gourav Kumar

Background and Objective: The study aimed to investigate the augmented cytotoxic effects of polymer-coated (poly-lactic-co-glycolic acid-PLGA) gold nanoparticles (GNPs) carrying 5-fluorouracil (5-FU) in the management of lung cancer. Materials and Methods: In this study, several formulations were prepared using a double emulsion (water-oil-water) method and evaluated for drug release behavior, compatibility, cell line toxicity (A549), and apoptosis assessment. Results: Characterization results showed spherical polydispersed particles with size 29.11-178.21 nm, polydispersity index (PDI) 0.191-292, and zeta potential (ZP) 11.19-29.21 (-mV), respectively. The optimized polymer-coated 5-FU loaded gold nanoparticles (PFGNPs) illustrated a maximum drug loading (93.09 ± 10.75%) compared to others. The percent cumulative drug release of polymer-coated 5-FU loaded nanoparticles (PFNPs), 5-FU loaded gold nanoparticles (FGNPs), (PFGNPs) and 5-FU solution were 47.87± 1.5, 41.09±1.8, 56.31±1.05, and 98.8±4.2%, respectively, over 10 h. following zero-order release kinetics (except 5-FU solution). From the MTT results, the cytotoxic effect of PFGNPs on the A549 cells was 82.89 % compared to the 5-FU solution (74.91 %). EGFR and KRAS gene expression analysis under the influence of PFNPs, FGNPs, PFGNPs, and 5-FU was studied and observed maximum potency for PFNPs. Conclusion: PLGA coated biogenic gold nanoparticles have a combined effect to achieve high drug loading, sustained delivery, improved efficacy, and enhanced permeation. Conclusively, the approach may be promising to control lung cancer with reduced toxicity and improved efficacy.


2015 ◽  
Vol 13 (2) ◽  
pp. 149-166 ◽  
Author(s):  
Navid Jubaer Ayon ◽  
Ikramul Hasan ◽  
Md Shfiqul Islam ◽  
Md Selim Reza

Polymeric microspheres of gliclazide were prepared to provide sustained release delivery of gliclazide to aid in continuous therapy with high margin of safety. Gliclazide was microencapsulated with different polymers namely HPMC K100LV, Ethocel (20 cps) and HPMC K100M by emulsion solvent evaporation technique using acetone as internal phase and liquid paraffin as external phase. Seventeen formulations were prepared using different drug loading and polymeric ratio of which nine formulations were prepared by a 32 full factorial design. Each formulation was evaluated for flow properties, particle size, surface morphology, drug entrapment efficiency, drug release and compatibility. Yield (%) for every batch of microspheres was measured. Flow properties of the microspheres were examined by determining bulk density, tapped density, Carr’s compressibility index, Hausner ratio and angle of repose. Particle size distribution was examined by sieving and particle size analyzer. Surface morphology was determined by scanning electron microscopy (SEM). In-vitro drug release was studied in a paddle type dissolution apparatus (USP Type II Dissolution Apparatus) for a period of 8 hours at 37°C using phosphate buffer ( pH 7.4). FTIR and DSC studies established compatibility of the drug with the polymers. Microspheres prepared with Ethocel (20 cps) and HPMC K100M were free flowing than those prepared only with HPMC K100LV. Entrapment efficiencies were within 75.88-99.69%. Microspheres prepared with Ethocel (20 cps) and HPMC K100M showed more sustained release when compared to microspheres prepared with HPMC K100LV only. Increase in drug loading resulted in increased drug release for the microspheres. Kinetic modeling of in vitro dissolution profiles revealed the drug release mechanism ranging from diffusion controlled to anomalous type. Ethocel and HPMC K100M in a ratio of 1:3 exhibited better sustained release properties than 1:1 and 3:1 ratios. The release rate of gliclazide from microspheres prepared with Ethocel (20 cps) and HPMC K100M was less than the release rate of gliclazide from microspheres prepared with HPMC K100LV, demonstrating Ethocel and HPMC K100M as suitable polymeric blend for preparing the controlled release formulation for gliclazide whereas, HPMC K100LV was found not suitable candidate when used alone as a polymer. DOI: http://dx.doi.org/10.3329/dujps.v13i2.21893 Dhaka Univ. J. Pharm. Sci. 13(2): 149-166, 2014 (December)


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