Improved drug delivery to the lower intestinal tract with tablets compression-coated with enteric/nonenteric polymer powder blends

Rujivipat, Soravoot; Bodmeier, Roland

doi:10.1016/j.ejpb.2010.09.004

Cited by 31 publications

(20 citation statements)

References 21 publications

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“…At a specified time interval, tablets were taken out from the media, dried at 60°C (until constant weight was not achieved), and reweighed ( W d ). The % coat erosion was calculated using the following formula [33]:

\begin{matrix} Coat erosion (%) = \frac{W_{d}}{W_{i}} \times normal100 . \end{matrix}

…”

Section: Methodsmentioning

confidence: 99%

Design, Development, and Optimization of Polymeric Based‐Colonic Drug Delivery System of Naproxen

Sharma

Chawla

Pawar

2013

The Scientific World Journal

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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. The in vitro drug 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 highest in vitro drug 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.

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\begin{matrix} Coat erosion (%) = \frac{W_{d}}{W_{i}} \times normal100 . \end{matrix}

…”

Section: Methodsmentioning

confidence: 99%

Design, Development, and Optimization of Polymeric Based‐Colonic Drug Delivery System of Naproxen

Sharma

Chawla

Pawar

2013

The Scientific World Journal

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“…About 95-99% drug was released from the core tablets within 15 min (data not shown). Rapid release indicates that the release from the core tablets was not a rate-limiting step (37,38). A number of variables both in the core tablets and composition of the compression coat may be a determinant factor in achieving slow-fast type sigmoidal drug release pattern.…”

Section: Discussionmentioning

confidence: 99%

Compression-Coated Tablet for Colon Targeting: Impact of Coating and Core Materials on Drug Release

Maity

2015

AAPS PharmSciTech

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Abstract. This work was envisaged to develop compression-coated tablets using a blend of Ca +2 ion crosslinked carboxymethyl xanthan gum (CMXG) and sodium alginate (SAL) for delayed release of immediate pulse release tablets of prednisolone (PDL) in the colon without the need of colonic bacterial intervention for degradation of the polysaccharide coat. The core tablets containing PDL and other compatible excipients were prepared by direct compression method and subsequently compression coated with different ratios of CMXG and SAL. Long T lag , the time required to restrict the drug release below 10%, and short T rap , the time required for immediate release following the T lag , were considered as suitable release parameters for evaluation of colon targeting of PDL tablets. Among the various compression coats, a blend of CMXG and SAL in a ratio of 1.5:3.5 provided T lag of 5.12±0.09 h and T rap of 6.50±0.05 h. The increase in microcrystalline cellulose (MCC) and crospovidone (CP) in the core tablets did not change T lag significantly although decreased the T rap marginally. Inclusion of an osmogen in the core tablets decreased the T lag to 4.05±0.08 h and T rap to 3.56±0.06 h. The increase in coat weight to 225 mg provided a reasonably long T lag (6.06±0.09 h) and short T rap (4.36±0.20 h). Drug release from most of the formulations followed the Hixson-Crowell equation and sigmoidal pattern as confirmed by the Weibull equation. In conclusion, tablets, compression coated with CMXG and SAL in a ratio of 1.5:3.5 and having 225-mg coat weight, were apparently found suitable for colon targeting.

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“…A swellable core encapsulated by rupturable outer coat, engineered using a combination of water soluble and water insoluble polymers, can be contrived to fabricate a time-controlled PR formulation [12][13][14][15] . Various coating strategies such as pan coating, fluidized bed coating, compression coating, and so on can be employed to achieve a desired lag time which is the key element of a PR formulation [2][3][4]6,10 .…”

Section: Introductionmentioning

confidence: 99%

Investigating effects of hydroxypropyl methylcellulose (HPMC) molecular weight grades on lag time of press-coated ethylcellulose tablets

Patadia

Vora

Mittal

et al. 2015

Pharmaceutical Development and Technology

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The research undertaken exemplifies the effects of hydroxypropyl methylcellulose (HPMC) molecular weight (MW) grades of on lag time of press-coated ethylcellulose (EC) tablets. The formulation comprised an immediate release core (containing prednisone as a model drug) surrounded by compression coating with variegated EC-HPMC blends. Five selected HPMC grades (E5, E15, E50, K100LV and K4M) were explored at three different concentrations (10% w/w, 20% w/w and 30% w/w in outer coat) to understand their effects on lag time and drug release. In vitro drug release testing demonstrated that, with increase in concentration of E5 and E15, up to 30% w/w, the mean lag time decreased progressively; whereas with remaining grades, the mean lag time initially decreased up to 20% w/w level and thereafter increased for 30% w/w level. Importantly, with increase in HPMC concentration in the outer coat, the variability in lag time (%RSD; n = 6) was decreased for each of E5, E15 and E50, whereas increased for K100LV and K4M. In general, the variability in lag time was increased with increase in HPMC MW at studied concentration levels. Markedly, tablets with 30% w/w K4M in outer coat exhibited slight premature release (before the rupture of outer coat) along with high variability in lag time. Overall, the study concluded that low MW HPMCs (E5, E15 and E50) were found rather efficient than higher MW HPMCs for developing robust EC-based press-coated pulsatile release formulations where precise lag time followed by sharp burst release is desired.

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Improved drug delivery to the lower intestinal tract with tablets compression-coated with enteric/nonenteric polymer powder blends

Cited by 31 publications

References 21 publications

Design, Development, and Optimization of Polymeric Based‐Colonic Drug Delivery System of Naproxen

Design, Development, and Optimization of Polymeric Based‐Colonic Drug Delivery System of Naproxen

Compression-Coated Tablet for Colon Targeting: Impact of Coating and Core Materials on Drug Release

Investigating effects of hydroxypropyl methylcellulose (HPMC) molecular weight grades on lag time of press-coated ethylcellulose tablets

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