Solid-state characterization of rifampicin samples and its biopharmaceutic relevance

Agrawal, Shrutidevi; Ashokraj, Yasvanth; Bharatam, Prasad V.; Pillai, Omathanu; Panchagnula, Ramesh

doi:10.1016/j.ejps.2004.02.011

Cited by 142 publications

(110 citation statements)

References 20 publications

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“…Table 2 shows that ΔT and fwhm (full-width half-maximum) decrease by the addition of rifampicin on PVA matrix, indicating simultaneous increases in the rate of melting and the average crystalline size. Rifampicin shows its melting followed by recrystallization and decomposition in the range of 180-223°C and 247-266°C, respectively [20]. Unfortunately, the melting temperature of PVA is located at the same range.…”

Section: Resultsmentioning

confidence: 98%

Effect of sepiolite on the physical properties and swelling behavior of rifampicin-loaded nanocomposite hydrogels

Viçosa¹,

Gomes²,

Soares³

et al. 2009

Express Polym. Lett.

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Abstract. Nanocomposite hydrogels based on poly(vinyl alcohol) -PVA and sepiolite have been prepared and their potential for drug delivery systems has been assessed by taking rifampicin as model drug. The nanocomposite hydrogels were characterized by WAXS and DSC and the swelling behavior and structural stability were evaluated. The effect of the presence of rifampicin, sepiolite and simultaneous rifampicin-sepiolite on the structure and swelling of the hydrogels was investigated. The swelling data were analyzed in order to evaluate the diffusion mechanisms of water. The results indicate that both rifampicin and sepiolite cause important modifications on microstructure of the PVA matrix, leading to changes on swelling and diffusional behavior.

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Section: Resultsmentioning

confidence: 98%

Effect of sepiolite on the physical properties and swelling behavior of rifampicin-loaded nanocomposite hydrogels

Viçosa¹,

Gomes²,

Soares³

et al. 2009

Express Polym. Lett.

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“…Pristine RIF showed the thermal behaviour of polymorphic form I [57], in which the only thermal transition observed is a single decomposition exotherm. After lyophilization the thermal properties of the pure drug were altered.…”

Section: Thermal Properties Upon Lyophilizationmentioning

confidence: 99%

Cryoprotection–lyophilization and physical stabilization of rifampicin-loaded flower-like polymeric micelles

Morettón

Chiappetta

Sosnik

2011

J. R. Soc. Interface.

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Rifampicin-loadedpoly(e-caprolactone)-b-poly(ethylene glycol) -poly(e-caprolactone) flower-like polymeric micelles display low aqueous physical stability over time and undergo substantial secondary aggregation. To improve their physical stability, the lyoprotectionlyophilization process was thoroughly characterized. The preliminary cryoprotectant performance of mono-and disaccharides (e.g. maltose, glucose), hydroxypropyl-bcyclodextrin (HPbCD) and poly(ethylene glycol) (PEG) of different molecular weights was assessed in freeze -thawing assays at 2208C, 2808C and 21968C. The size and size distribution of the micelles at the different stages were measured by dynamic light scattering (DLS). A cryoprotectant factor ( f c ) was determined by taking the ratio between the size immediately after the addition of the cryoprotectant and the size after the preliminary freeze -thawing assay. The benefit of a synergistic cryoprotection by means of saccharide/ PEG mixtures was also assessed. Glucose (1 : 20), maltose (1 : 20), HPbCD (1 : 5) and glucose or maltose mixtures with PEG3350 (1 : 20) (copolymer:cryoprotectant weight ratio) were the most effective systems to protect 1 per cent micellar systems. Conversely, only HPbCD (1 : 5) cryoprotected more concentrated drug-loaded micelles (4% and 6%). Then, those micelle/ cryoprotectant systems that displayed f c values smaller than 2 were freeze-dried. The morphology of freeze-dried powders was characterized by scanning electron microscopy and atomic force microscopy and the residual water content analysed by the Karl Fisher method. The HPbCD-added lyophilisates were brittle porous cakes (residual water was between 0.8% and 3%), easily redispersable in water to form transparent systems with a minimal increase in the micellar size, as determined by DLS.

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“…The FTIR result indicated that the purchased rifampicin was in the crystalline form I state. Agrawal et al (29) reported using the IR spectrum as a , but CH alkyl stretching band at 2,922 and at 2,848 cm −1 for mPEG2000-DSPE, while a characteristic sharp peak was observed at 2,885 cm −1 for mPEG5000-DSPE (Figs. 3 and 4).…”

Section: Ftirmentioning

confidence: 99%

Rehydrated Lyophilized Rifampicin-Loaded mPEG–DSPE Formulations for Nebulization

2010

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Abstract. Rifampicin-loaded nanoparticles were prepared using two different molecular weights of poly-(ethylene oxide)-block-distearoyl phosphatidyl-ethanolamine (mPEG2000-DSPE and mPEG5000-DSPE) polymers. Particle sizes of all formulations studied were in the range of 162-395 nm. The entrapment efficiency (EE) was not affected by the copolymer's molecular weight, and the highest EE (100%) was obtained with drug to copolymer ratio of 1:5. The differential scanning calorimetry (DSC) thermograms showed Tg of rifampicin-loaded PEG-DSPE nanoparticles that shifted to a lower value, indicating entrapment of rifampicin in polymer matrix. The Fourier transformed infrared spectra revealed no chemical interactions between the drug and both copolymers. The in vitro drug release from the formulations occurred over 3 days and followed first-order release kinetic and Higuchi diffusion model. The nebulization of rehydrated lyophilized rifampicin mPEG-DSPE formulations had mass median aerodynamic diameter of 2.6 µm and fine particle fraction of 42%. The aerodynamic characteristic of the preparations was not influenced by the molecular weight of the copolymers. Therefore, it is suggested that both mPEG-DSPE are promising candidates as rifampicin carrier for pulmonary delivery.

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Solid-state characterization of rifampicin samples and its biopharmaceutic relevance

Cited by 142 publications

References 20 publications

Effect of sepiolite on the physical properties and swelling behavior of rifampicin-loaded nanocomposite hydrogels

Effect of sepiolite on the physical properties and swelling behavior of rifampicin-loaded nanocomposite hydrogels

Cryoprotection–lyophilization and physical stabilization of rifampicin-loaded flower-like polymeric micelles

Rehydrated Lyophilized Rifampicin-Loaded mPEG–DSPE Formulations for Nebulization

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