Microencapsulation of zidovudine by double emulsion solvent diffusion technique using ethylcellulose

Das, MK; Rao, K. Surya Prakasa

doi:10.4103/0250-474x.33151

Cited by 20 publications

(16 citation statements)

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“…However the surface of MS was rough with a porous texture (Figure 2b). This is in confirmation with earlier reports on MS prepared with ethyl cellulose polymer 42,43 .…”

Section: Iii) Scanning Electron Microscopysupporting

confidence: 93%

“…High correlation observed in the Higuchi plot rather than first-order and zero-order models indicated matrix controlled drug release kinetics. Previously reported Zidovudine MS prepared using ethyl cellulose has shown similar release profile 42,43 . Table 3 reports the evaluation of physical properties like bulk density, tap density, percent compressibility and Hausner ratio of blends ready for compression for all ODT-SR batches.…”

Section: V) In-vitro Drug Releasementioning

confidence: 77%

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Formulation and development of orodispersible sustained release tablet of domperidone

Patil

Tiwari

Repka

et al. 2015

Drug Development and Industrial Pharmacy

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Abstract:Commercially available domperidone orodispersible tablets (ODT) are intended for immediate release of the drug but none of them have been formulated for sustained action. The aim of the present research work was to develop and evaluate orodispersible sustained release tablet (ODT-SR) of domperidone, which has the convenience of ODT and benefits of controlled release product combined in one. The technology comprised of developing sustained release microspheres (MS) of domperidone, followed by direct compression of MS along with suitable excipients to yield ODT-SR which rapidly disperses within 30 seconds and yet the dispersed MS maintain their integrity to have a sustained drug release. The particle size of the MS was optimized to be less than 200 μm to avoid the grittiness in the mouth. The DSC thermograms of MS showed the absence of drug-polymer interaction within the microparticles, while SEM confirmed their spherical shape and porous nature. Angle of repose, compressibility and Hausner's ratio of the blend for compression showed good flowability and high percent compressibility. The optimised ODT-SR showed disintegration time of 21 seconds and matrix controlled drug release for 9 h. Invivo pharmacokinetic studies in Wistar rats showed that the ODT-SR had a prolonged MRT of 11.16 h as compared 3.86 h of conventional tablet. The developed technology is easily scalable and holds potential for commercial exploitation.

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“…However the surface of MS was rough with a porous texture (Figure 2b). This is in confirmation with earlier reports on MS prepared with ethyl cellulose polymer 42,43 .…”

Section: Iii) Scanning Electron Microscopysupporting

confidence: 93%

Section: V) In-vitro Drug Releasementioning

confidence: 77%

Formulation and development of orodispersible sustained release tablet of domperidone

Patil

Tiwari

Repka

et al. 2015

Drug Development and Industrial Pharmacy

View full text Add to dashboard Cite

show abstract

“…Calculation of Higuchi's correlation coefficient confirms that drug release was proportional to the square root of time indicating that zidovudine release from niosomes was diffusion controlled. The n value from the Korsmeyer-Peppas model for zidovudine niosomal formulation was between 0.23 and 0.54 which confirms the Fickian type diffusion, whereas Tween 60 and 80 formulations with DCP follow an anomalous diffusion mechanism with erosion (n>0.54) (31). Release profiles fitted into a Hixson-Crowell model further confirmed that drug release from niosomes followed anomalous diffusion…”

Section: In Vitro Releasementioning

confidence: 58%

Formulation and Optimization of Zidovudine Niosomes

Kandasamy¹,

2010

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Abstract. Zidovudine (AZT) is commonly used to treat patients with AIDS, but it is limited by toxicity and high dosing needs. Alternative formulations have been proposed to overcome these drawbacks. The objective of this study was to evaluate process-related variables like hydration and sonication time, rotation speed of evaporation flask, and the effects of charge-inducing agent and centrifugation on zidovudine entrapment and release from niosomes. Formulation of zidovudine niosomes was optimized by altering the proportions of Tween, Span and cholesterol. The effect of process-related variables like hydration time, sonication time, charge-inducing agent, centrifugation and rotational speed of evaporation flask on zidovudine entrapment and release from niosomes was evaluated. The effect of changes in osmotic shock and viscosity were also evaluated. Non-sonicated niosomes were in the size range of 2-3.5 μm and sonicated niosomes formulated with Tween 80 and dicetylphosphate (DCP) had a mean diameter of 801 nm. Zidovudine niosomes formulated with Tween 80 entrapped high amounts of drug and the addition of DCP enhanced drug release for a longer time (88.72% over 12 h). The mechanism of release from Tween 80 formulation was the Fickian type and obeyed first-order release kinetics. Niosomes can be formulated by proper adjustment of process parameters to enhance zidovudine entrapment and sustainability of release. These improvements in zidovudine formulation may be useful in developing a more effective AIDS therapy.

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“…EC is a water-insoluble polymer; it has been widely used in microencapsulation in order to retard the release of many drugs (33)(34)(35)(36). Being hydrophobic in nature (37), EC is expected to prolong the release of 5-ASA from ES100-based microspheres at pHs higher than the threshold of ES100 ionization (pH 7).…”

Section: Microspheres With Varying Drug-to-polymeric-blends Ratiomentioning

confidence: 99%

Influence of Some Formulation Variables on the Optimization of pH-dependent, Colon-targeted, Sustained-release Mesalamine Microspheres

El-Bary¹,

Aboelwafa²,

Sharabi³

2011

AAPS PharmSciTech

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Abstract. The aim of this work was to understand the influence of different formulation variables on the optimization of pH-dependent, colon-targeted, sustained-release mesalamine microspheres prepared by O/O emulsion solvent evaporation method, employing pH-dependent Eudragit S and hydrophobic pHindependent ethylcellulose polymers. Formulation variables studied included concentration of Eudragit S in the internal phase and the ratios between; internal to external phase, drug to Eudragit S and Eudragit S to ethylcellulose to mesalamine. Prepared microspheres were evaluated by carrying out in vitro release studies and determination of particle size, production yield, and encapsulation efficiency. In addition, morphology of microspheres was examined using optical and scanning electron microscopy. Emulsion solvent evaporation method was found to be sensitive to the studied formulation variables. Particle size and encapsulation efficiency increased by increasing Eudragit S concentration in the internal phase, ratio of internal to external phase, and ratio of Eudragit S to the drug. Employing Eudragit S alone in preparation of the microspheres is only successful in forming acid-resistant microspheres with pulsatile release pattern at high pH. Eudragit S and ethylcellulose blend microspheres were able to control release under acidic condition and to extend drug release at high pH. The stability studies carried out at 40°C/75% RH for 6 months proved the stability of the optimized formulation. From the results of this investigation, microencapsulation of mesalamine in microspheres using blend of Eudragit S and ethylcellulose could constitute a promising approach for site-specific and controlled delivery of drug in colon.

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Microencapsulation of zidovudine by double emulsion solvent diffusion technique using ethylcellulose

Cited by 20 publications

References 0 publications

Formulation and development of orodispersible sustained release tablet of domperidone

Formulation and development of orodispersible sustained release tablet of domperidone

Formulation and Optimization of Zidovudine Niosomes

Influence of Some Formulation Variables on the Optimization of pH-dependent, Colon-targeted, Sustained-release Mesalamine Microspheres

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