scholarly journals DEVELOPMENT OF MESALAZINE MICROSPHERES FOR COLON TARGETING

2017 ◽  
Vol 9 (4) ◽  
pp. 1
Author(s):  
Katta Rajesh ◽  
R. Deveswaran ◽  
S. Bharath ◽  
B. V. Basavaraj

Objective: The present work was aimed at preparation of mesalazine microspheres by a non-aqueous solvent evaporation method using eudragit S 100 and eudragit L 100 as pH dependent polymers for colon targeting.Methods: The ratio of drug to polymer was varied and the effect of formulation variables revolutions per minute (RPM) (1000, 1500, 2000 and 2500) and concentration of span 80 (1%, 1.5%, 2% and 2.5%) were studied. Prepared microspheres were evaluated for particle size, percent drug entrapment, granular analysis, in vitro drug release studies, Fourier transformed infrared spectroscopy (FT-IR) Differential Scanning Calorimetry (DSC), X-ray diffraction (XRD) and scanning electron microscopy (SEM) studies.Results: Particle size has decreased and percent drug entrapment had increased with increase in RPM in all formulations. When the span 80 concentration increased, the particle size of the microsphere formulations increased and percent drug entrapment decreased in eudragit S 100 microspheres; whereas in eudragit L 100 microspheres, as the concentration of span 80 increased, the particle size of the microsphere formulations decreased. The prepared microspheres sustained the drug release over a period of 12 h.Conclusion: Thus eudragit S 100 and eudragit L 100 microspheres could constitute a promising approach for colon-specific and sustained delivery of mesalazine for the treatment of inflammatory bowel disease.

2012 ◽  
Vol 62 (4) ◽  
pp. 529-545 ◽  
Author(s):  
Anuj Chawla ◽  
Pooja Sharma ◽  
Pravin Pawar

The aim of the study was to prepare site specific drug delivery of naproxen sodium using sodium alginate and Eudragit S-100 as a mucoadhesive and pH-sensitive polymer, respectively. Core microspheres of alginate were prepared by a modified emulsification method followed by cross-linking with CaCl2, which was further coated with the pH dependent polymer Eudragit S-100 (2.5 or 5 %) to prevent drug release in the upper gastrointestinal environment. Microspheres were characterized by FT-IR spectroscopy, X-ray diffraction, differential scanning calorimetry and evaluated by scanning electron microscopy, particle size analysis, drug loading efficiency, in vitro mucoadhesive time study and in vitro drug release study in different simulated gastric fluids. Stability studies of the optimized formulation were carried out for 6 months. SEM images revealed that the surface morphology was rough and smooth for core and coated microspheres, respectively. Core microspheres showed better mucoadhesion compared to coated microspheres when applied to the mucosal surface of freshly excised goat colon. The optimized batch of core microspheres and coated microspheres exhibited 98.42 ± 0.96 and 95.58 ± 0.74 % drug release, respectively. Drug release from all sodium alginate microsphere formulations followed Higuchi kinetics. Moreover, drug release from Eudragit S-100 coated microspheres followed the Korsmeyer-Peppas equation with a Fickian kinetics mechanism. Stability study suggested that the degradation rate constant of microspheres was minimal, indicating 2 years shelf life of the formulation.


INDIAN DRUGS ◽  
2013 ◽  
Vol 50 (10) ◽  
pp. 30-38
Author(s):  
S Vidyadhara ◽  
◽  
R. L. C. Sasidhar ◽  
P Thrilochani ◽  
L. K. Lavanya

The present investigation was focused on the development and evaluation of controlled release pellets of losartan potassium with Eudragit S 100 and hydroxypropyl methyl cellulose phthalate (HPMCP) by employing pan coating technique. Eudragit S 100, a high viscosity grade controlled release polymer, was mainly used as coating agent for regulating the drug release from pellets. HPMCP, an enteric coating polymer was used in the present study to regulate the drug release at varied G.I. pH conditions. The prepared pellets were evaluated for particle size, drug content, friability and for in vitro drug release. The formulations were further characterized to identify any possible interactions by FTIR spectroscopy and differential scanning calorimetry. The surface morphology of the pellets was studied by scanning electron microscopy. From the results it was observed that due to increase in the concentration of Eudragit the drug release was extended up to 12 hours. The increase in the HPMCP polymeric concentration in formulations showed initial delay in drug release.


Author(s):  
Krutika Sawant ◽  
Mitali Patel ◽  
Jiten Patel ◽  
Piyush Mundada

<p><strong>Objective: </strong>The objective of the present investigation was to prepare gastro-resistant microspheres of esomeprazole magnesium trihydrate (EMT) to prevent its degradation in the acidic environment of the stomach and enhance its bioavailability via intestinal absorption.</p><p><strong>Methods: </strong>EMT loaded gastro-resistant microspheres were prepared using hypromellose acetate succinate (HPMCAS) as the gastro-resistant polymer by ‘non-aqueous solvent evaporation’ technique. A 3-factor 3 level factorial design was used to optimise EMT: HPMCAS ratio, the concentration of Span 80 and stirring speed with respect to percent entrapment efficiency and particle size. Further characterization was carried out using scanning electron microscopy (SEM), differential scanning calorimetry (DSC), <em>In vitro</em> release study and <em>In vivo</em> anti-ulcer activity.</p><p><strong>Results: </strong>Fourier transform infrared <strong>(</strong>FTIR) study indicated compatibility between drug and polymer. DSC study revealed that the drug was molecularly dispersed in the polymer. The optimised batch showed 49.63±1.23% drug entrapment and 170.12±3.36 μm particle size. SEM study showed that microspheres were spherical in shape<strong>. </strong><em>In vitro</em> drug release study showed only 4.28±1.23% drug release in simulated gastric media in 2 hr and 93.46±1.20% release in simulated intestinal media after 1 hr from the optimised batch.</p><p><strong>Conclusion: </strong>Results of <em>in vitro </em>release studies indicated the gastro-resistant nature of the developed microspheres. <em>In vivo</em> anti-ulcer activity demonstrated that EMT loaded microspheres were able to significantly reduce ethanol-induced ulcer formation in rats’ stomach as compared to the aqueous solution of EMT. So it can be concluded that the developed gastro-resistant microspheres of EMT prevented drug release in the stomach which would lead to a significant improvement in its bioavailability through enhanced intestinal absorption</p>


2016 ◽  
Vol 15 (1) ◽  
pp. 47-55
Author(s):  
Md Ataur Rahman ◽  
Nusrat Ahmed ◽  
Ikramul Hasan ◽  
Md Selim Reza

In the present study naproxen loaded microspheres were prepared by emulsification solvent evaporation method in order to achieve targeted drug delivery. Eudragit L 100 and Eudragit S 100 were used as the rate retardant polymers in the preparations. Thirteen formulations (F1-F13) were prepared using 22 factorial design by changing the concentration of these two polymers. All the formulations were evaluated for product yield, drug content, entrapment efficiency, particle size and drug release profiles. Highest drug content and entrapment efficiency were found to be 30.17% (F4) and 91.86% (F8) respectively. The particle size was found to be 159.26-234.70 ?m for all formulations. In-vitro drug release studies were performed using USP type II (Paddle) apparatus for 8 hrs in pH 7.4 phosphate buffer. The maximum drug release after 8 hrs was found to be 60.19% for batch F4. The release kinetics of all formulations were evaluated by using zero order, first order, Higuchi, Korsmeyer-Peppas, Kopcha and Hixson Crowell model. Almost all formulations fitted best with the Kopcha kinetic model. The SEM study indicated the spherical structure of the microspheres having rough surfaces.Dhaka Univ. J. Pharm. Sci. 15(1): 47-55, 2016 (June)


2013 ◽  
Vol 2013 ◽  
pp. 1-12 ◽  
Author(s):  
Pooja Sharma ◽  
Anuj Chawla ◽  
Pravin Pawar

The aim of present investigation deals with the development of time-dependent and pH sensitive press-coated tablets for colon specific drug delivery of naproxen. The core tablets were prepared by wet granulation method then press coated with hydroxypropyl cellulose (HPC) or Eudragit RSPO : RLPO mixture and further coated with Eudragit S-100 by dip immerse method. Thein vitrodrug release study was conducted in different dissolution media such as pH 1.2, 6.8, and 7.4 with or without rat caecal content to simulate GIT conditions. Surface morphology and cross-sectional view of the tablets were visualized by scanning electron microscopy (SEM). All prepared batches were in compliance with the pharmacopoeial standards. The tablets which are compression coated with HPC followed by Eudragit S-100 coated showed highestin vitrodrug release of 98.10% in presence of rat caecal content. The SEM of tablets suggested that the number of pores got increased in pH 7.4 medium followed by dissolution of coating layer. The tablets coat erosion study suggested that the lag time depends upon the coating concentrations of polymers. A time-dependent hydrophilic polymer and pH sensitive polymer based press-coated tablets of naproxen were promising delivery for colon targeting.


Author(s):  
Pravin S Patil ◽  
Shashikant C Dhawale

 Objective: The purpose of the present investigation was to develop a nanosuspension to improve dissolution rate and oral bioavailability of ritonavir.Methods: Extended-release ritonavir loaded nanoparticles were prepared using the polymeric system by nanoprecipitation technique. Further, the effect of Eudragit RL100 (polymeric matrix) and polyvinyl alcohol (surfactant) was investigated on particle size and distribution, drug content, entrapment efficiency, and in vitro drug release from nanosuspension where a strong influence of polymeric contents was observed. Drug-excipient compatibility and amorphous nature of drug in prepared nanoparticles were confirmed by Fourier transform infrared spectroscopy, differential scanning calorimetry, and powder X-ray diffraction studies, respectively.Results: Hydrophobic portions of Eudragit RL100 could result in enhanced encapsulation efficiency. However, increase in polymer and surfactant contents lead to enlarged particle size proportionately as confirmed by transmission electron microscopy. Nanosuspension showed a significant rise in dissolution rate with complete in vitro drug release as well as higher bioavailability in rats compared to the pure drug.Conclusion: The nanoprecipitation technique used in present research could be further explored for the development of different antiretroviral drug carrier therapeutics.


Author(s):  
Sanjeevani S Deshkar ◽  
Kiran G Sonkamble ◽  
Jayashri G Mahore

Objective: The study aims at the formulation and optimization of gemfibrozil (Gem) nanosuspension (NS) for improving its solubility and dissolution rate.Method: Gem NS was prepared by precipitation-ultrasonication method using ethanol as solvent, water as anti-solvent, and polyvinyl alcohol (PVA) as a stabilizer. A Box–Behnken design was employed to study the effect of the independent variables, Gem concentration in the organic phase (X1), PVA concentration (X2) and sonication time (X3) on the dependent variable, drug release after 90 min (Y). The resulting data were statistically analyzed and subjected to 3D response surface methodology to study the influence of variables on the response. NS was evaluated for particle size, zeta potential, solubility and in vitro drug release and characterized using Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), and X-ray diffractometry (XRD).Results: On the basis of the evaluation, NS4 formulation (with 80 mg/ml Gem, 0.5% PVA concentration, and 20 min of sonication time) demonstrated highest drug content with a particle size of 191.0 nm and zeta potential of −12.0 mV. Dissolution profiles of NS indicated 2.5-fold increase in drug release than pure drug. NS demonstrated 5- and 9-fold increase in solubility, in water, and phosphate buffer (pH 7.5), respectively, pure drug. DSC and XRD studies indicated changes in the crystallinity of Gem during NS formulation. No chemical change was evident in NS as indicated by FTIR.Conclusion: Gem NS formulation could serve as a promising approach for improving its solubility and dissolution rate.


2018 ◽  
Vol 10 (4) ◽  
pp. 133 ◽  
Author(s):  
Shweta Gedam ◽  
Pritee Jadhav ◽  
Swati Talele ◽  
Anil Jadhav

Objective: The present investigation was undertaken to develop and evaluate a gastroretentive mucoadhesive microspheres of anti-osteoporosis drug risedronate sodium to enhance the residence time and drug release by studying the effect of the crosslinking agent to obtain the best formulation with reduced particle size and good in vitro mucoadhesion strength.Methods: Selected drug risedronate sodium is a potent pyridinyl bisphosphonate used for the treatment of osteoporosis, and other bone disorders. Microspheres using sodium alginate as a polymer and calcium chloride solution as a cross-linker were prepared successfully by the emulsification crosslinking method. The 23 factorial design was used to study the effects of various variables like a drug: polymer ratio, crosslinking agent concentration and crosslinking time on the particle size and in vitro mucoadhesion strength. All these formulations were evaluated for entrapment efficiency, percentage yield and cumulative drug release. F1 batch was selected as best formulation and evaluated for scanning electron microscopy, fourier transforms infrared spectroscopy, differential scanning calorimetry, stability study.Results: Design batches were evaluated for percent yield (61.29-89.33%), % entrapment efficiency (42.25±0.620-62.58±0.330), mucoadhesion strength (68.15±0.37-82.24±0.72%) and drug release at 12 h (67-84%). Among the microspheres formulation, an F1 batch of (0.5:1) drug: polymer concentration and at 4% concentration of calcium chloride as a crosslinker was considered best formulation with reduced particle size 32.85±0.774μm, % intro mucoadhesion. 82.24±0.72. In vitro mucoadhesion strength was increased with the increasing crosslinking time from 5 min to 10 min. The fourier transform infrared spectroscopy (FTIR) and differential scanning calorimetry (DSC) study showed no interaction between drug and polymer. X-ray diffraction (XRD) spectrum of microspheres indicates that drug particles are dispersed at the molecular level in the polymer matrices so no indication of the crystalline nature of the drug nature. Scanning electron microscopic (SEM) study showed that microspheres were spherical in shape with a smooth surface. F1 batch shows percentage cumulative drug release 84.07%. In vitro dissolution studies indicates that percent cumulative drug release from microspheres follows zero order kinetics plot which indicates controlled-release drug-delivery for 12 h which leads to control of plasma concentration.Conclusion: The results show that the formulation that contains (0.5:1) drug: polymer ratio, calcium chloride in 4% concentration and crosslinking time 10 min is the best one and can be utilized to formulate risedronate sodium mucoadhesive microspheres to enhance gastric residence time, improved patient compliance and reduction in the frequency of drug administration.


Author(s):  
Revathi S ◽  
Dhanaraju Md

 Objective: The study is to formulate and assess the effects of different variables on the release profile of sitagliptin microspheres.Methods: The microspheres were prepared by emulsion-solvent diffusion method and ionotropic gelation method using ethyl cellulose and sodium alginate as the polymers, respectively. The formulations are optimized by applying 23 factorial design based on the drug-polymer ratio, stirring speed, and method of preparation.Results: The drug-polymer interaction was checked by the Fourier-transform infrared spectroscopy and differential scanning calorimetry the results of which indicated no incompatibility. The formulated sitagliptin microspheres were evaluated for shape, morphology, particle size, the degree of swelling, encapsulation efficiency, in vitro drug release studies for 12 h, and kinetics of drug release.Conclusion: The results showed that the drug-polymer ratio and stirring speed affected the particle size and drug release. The release of the drug was found to be sustained, and diffusion path is following cube root law of Hixson-Crowell kinetics. The batch F3 was found to be desirable and was further characterized by scanning electron microscope for morphology.


Author(s):  
SWATHI GANNA ◽  
SAI MANOGNA KOTAKADI ◽  
RESHMA ANJUM MOHAMMED ◽  
MANNUR ISMAIL SHAIK ◽  
JOHN SUSHMA NANNEPAGA

Objective: The objective of the present study was to develop Nanostructured lipid carriers (NLCs) for improvement in the oral bioavailability of RT. Methods: RT-loaded NLCs were prepared by high shear homogenization technique using fish oil and flaxseed oil respectively. The prepared RT-NLCs were characterized using a phase-contrast microscope, scanning electron microscope (SEM), atomic force microscope (AFM), Fourier transform-infrared spectroscopy (FTIR) and differential scanning calorimetry (DSC). Further, particle size, entrapment efficiency and sustained release of the drug were also studied. Results: SEM results revealed that the RT-NLCs were spherical in shape with a smooth surface. AFM results confirmed the formation of spherical particle dispersions by the NLCs in nanoscale. FTIR spectroscopy and DSC analyses revealed that there is no chemical interaction between the ingredients of RT-NLCs. The particle size of the RT-NLCs was found to be exponentially decreased with the increase in a surfactant solution. Conclusion: The results confirmed pronounced improvement in entrapment efficiency of optimized formulation of RT-NLCs. In vitro, drug release studies showed that RT-NLCs were capable of releasing the drug in a sustained manner. The experimental results showed that the NLCs are potential carriers for providing sustained delivery of rivastigmine.


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