Controlled and complete release of a model poorly water‐soluble drug, prednisolone, from hydroxypropyl methylcellulose matrix tablets using (SBE)7m‐β‐cyclodextrin as a solubilizing agent

2001 ◽  
Vol 90 (7) ◽  
pp. 807-816 ◽  
Author(s):  
Venkatramana M. Rao ◽  
John L. Haslam ◽  
Valentino J. Stella
2016 ◽  
Vol 52 (4) ◽  
pp. 751-759 ◽  
Author(s):  
Wendy Leticia Guerra-Ponce ◽  
Sandra Leticia Gracia-Vásquez ◽  
Patricia González-Barranco ◽  
Ivonne Antonieta Camacho-Mora ◽  
Yolanda Araceli Gracia-Vásquez ◽  
...  

2012 ◽  
Vol 506 ◽  
pp. 307-310 ◽  
Author(s):  
Benchawan Chamsai ◽  
Pornsak Sriamornsak

Solid dispersions of poorly water-soluble drug, indomethacin (IMC), and carriers at a ratio of 1:9 were prepared by melting method. The carriers used in this study were polyethylene glycol 4000 (PEG4000), hydroxypropyl methylcellulose (HPMC) and pectin. The solid dispersions obtained were characterized by powder x-ray diffractometry (PXRD) and dissolution studies. PXRD patterns showed that all solid dispersions led to amorphous products while their physical mixture still showed the crystalline state of drug. Crystalline drug was clearly detectable in solid dispersion products containing only IMC and PEG4000 after storage for 2 months. The formulations with biopolymer (i.e., HPMC, pectin or their combination) showed no drug crystal after storage. More than 80% of IMC dissolved within 5 minutes for all formulations after preparation while less than 40% of IMC dissolved, within 5 minutes, from the formulations containing IMC, PEG4000 and HPMC after storage for 2 months. The slower drug dissolution may be due to the gel-forming properties of HPMC as well as the agglomeration of the products after storage. The results suggested that either HPMC or pectin in solid dispersions can help to prevent the crystallization of amorphous IMC in solid dispersion, probably by a polymer anti-plasticizing effect. Pectin showed superior stabilizing effect with no retardation effect on drug dissolution.


Author(s):  
Khanh T. Nguyen ◽  
Phuong H.L. Tran ◽  
Hai V. Ngo ◽  
Thao T.D. Tran

Background: Although film-forming hydrogels possess the advantages of both film and hydrogel dosage forms, certain limitations still remain. Objective: This study aims to investigate the use of film-forming hydrogels and the effects of nanocarriers on the sustained release of a poorly water-soluble drug, curcumin. Methods: The film-forming hydrogels contained either zein or polyvinylpyrrolidone as a film former, in addition to hydroxypropyl methylcellulose, oleic acid, ethanol and water. Curcumin was encapsulated in poly(lactic-co-glycolic acid) and gelatine nanoparticles using a sonoprecipitation method. Free drug and drug-loaded nanoparticles were later dispersed into blank hydrogels to produce the film-forming nanogels. Results: The results suggested that the encapsulation of curcumin in nanoparticles could reduce the drug particle size to less than 200nm for easier diffusion and could shield curcumin from chemical interactions that limit its topical permeability. curcumin was more compatible with gelatine nanoparticles than with poly(lactic-coglycolic acid) nanoparticles, and gelatine nanoparticles, in turn, were more compatible with zein than with polyvinylpyrrolidone film-forming nanogels. Therefore, gelatine nanoparticles in zein filmforming nanogels greatly elevated the permeability of curcumin by over five times that afforded by gelatine nanoparticles in polyvinylpyrrolidone film-forming nanogels. Conclusion: This research suggested that film-forming nanogel is a promising drug delivery system for both improved permeability and sustained topical diffusion of the extremely hydrophobic drug curcumin depending on the compatibility between the nanocarrier and the film-forming hydrogel.


2012 ◽  
pp. 31-35
Author(s):  
Truong Dinh Thao Tran ◽  
Ha Lien Phuong Tran ◽  
Nghia Khanh Tran ◽  
Van Toi Vo

Purposes: Aims of this study are dissolution enhancement of a poorly water-soluble drug by nano-sized solid dispersion and investigation of machenism of drug release from the solid dispersion. A drug for osteoporosis treatment was used as the model drug in the study. Methods: melting method was used to prepare the solid dispersion. Drug dissolution rate was investigated at pH 1.2 and pH 6.8. Drug crystallinity was studied using differential scanning calorimetric and powder X-ray diffraction. In addition, droplet size and contact angle of drug were determined to elucidate mechanism of drug release. Results: Drug dissolution from the solid dispersion was significantly increased at pH 1.2 and pH 6.8 as compared to pure drug. Drug crystallinity was changed to partially amorphous. Also dissolution enhancement of drug was due to the improved wettability. The droplet size of drug was in the scale of nano-size when solid dispersion was dispersed in dissolution media. Conclusions: nano-sized solid dispersion in this research was a successful preparation to enhance bioavailability of a poorly water-soluble drug by mechanisms of crystal changes, particle size reduction and increase of wet property.


Author(s):  
Meka Lingam ◽  
Vobalaboina Venkateswarlu

The low aqueous solubility of celecoxib (CB) and thus its low bioavailability is a problem.    Thus, it is suggested to improve the solubility using cosolvency and solid dispersions techniques. Pure CB has solubility of 6.26±0.23µg/ml in water but increased solubility of CB was observed with increasing concentration of cosolvents like PEG 400, ethanol and propylene glycol. Highest solubility (791.06±15.57mg/ml) was observed with cosolvency technique containing the mixture of composition 10:80:10%v/v of water: PEG 400: ethanol. SDs with different polymers like PVP, PEG were prepared and subjected to physicochemical characterization using Fourier-transform infrared (FTIR) spectroscopy, X-ray diffractometry (XRD), differential scanning calorimetry (DSC), solubility and dissolution studies. These studies reveals that CB exists mainly in amorphous form in prepared solid dispersions of PVP, PEG4000 and PEG6000 further it can also be confirmed by solubility and dissolution rate studies. Solid dispersions of PV5 and PV9 have shown highest saturation solubility and dissolution rate


2002 ◽  
Vol 3 (2) ◽  
pp. 55-63 ◽  
Author(s):  
Gedela V. Murali Mohan Babu ◽  
Namballa R. Kumar ◽  
Kasina H. Sankar ◽  
Battu J. Ram ◽  
Namburu K. Kumar ◽  
...  

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