Synthesis of mesoporous magnesium phosphates as dispersing carriers for cryptotanshinone solid dispersions

2018 ◽  
Vol 15 (4) ◽  
pp. 938-946 ◽  
Author(s):  
Huan Zhou ◽  
Yaping Bi ◽  
Mengmeng Yang ◽  
Wenjie Wang ◽  
Xinye Ni ◽  
...  
2016 ◽  
Vol 2 (2) ◽  
pp. 91-95
Author(s):  
Neelima Rani T ◽  
Pavani A ◽  
Sobhita Rani P ◽  
Srilakshmi N

This study aims to formulate solid dispersions (SDs) of Simvastatin (SIM) to improve the aqueous solubility, dissolution rate and to facilitate faster onset of action. Simvastatin is a BCS class II drug having low solubility & therefore low oral bioavailability. In the present study, SDs of simvastatin different drug-carrier ratios were prepared by kneading method. The results showed that simvastatin solubility & dissolution rate enhanced with polymer SSG in the ratio 1:7 due to increase in wetting property or possibly may be due to change in crystallinity of the drug.


Author(s):  
Sumant Saini ◽  
Yashwant .

Solid dispersions are one of the most promising strategies to improve the oral bioavailability of poorly water soluble drugs. By reducing drug particle size to the absolute minimum, and hence improving drug wettability, bioavailability may be significantly improved. This article reviews the various preparation techniques for solid dispersion and compiles some of the recent technology transfers. The different types of solid dispersions based on the molecular arrangement have been highlighted. Some of the practical aspects to be considered for the preparation of solid dispersions, such as selection of carrier, solvent and methods of physicochemical characterization, along with an insight into the molecular arrangement of drugs in solid dispersions are also discussed. In this review, it is intended to discuss the recent advances related on the area of solid dispersions.


Author(s):  
Narendar D ◽  
Ettireddy S

The content of this investigation was to study the influence of β-cyclodextrin and hydroxy propyl-β-cyclodextrin complexation on enhancement of solubility and dissolution rate of isradipine. Based on preliminary phase solubility studies, solid complexes prepared by freeze drying method in 1:1 molar ratio were selected and characterized by DSC for confirmation of complex formation. Prepared solid dispersions were evaluated for drug content, solubility and in vitro dissolution. The physical stability of optimized formulation was studied at refrigerated and room temperature for 2 months. Solid state characterization of optimized complex performed by DSC and XRD studies.  Dissolution rate of isradipine was increased compared with pure drug and more with HP-β-CD inclusion complex than β-CD. DSC and XRD analyzes that drug was in amorphous form, when the drug was incorporated as isradipine β-CD and HP-β-CD inclusion complex. Stability studies resulted in low or no variations in the percentage of complexation efficiency suggesting good stability of molecular complexes. The results conclusively demonstrated that the enhancement of solubility and dissolution rate of isradipine by drug-cyclodextrin complexation was achieved.   


Author(s):  
Adel M. Aly ◽  
Ahmed S. Ali

: Glipizide (GZ) is an oral blood-glucose-lowering drug of the sulfonylurea class characterized by its poor aqueous solubility. Aiming for the production of GZ tablets with rapid onset of action followed by prolonged effect; GZ-Polyethylene glycol (PEG 4000 and 6000) solid dispersions with different ratios, (using melting and solvent evaporation method), as well as, coprecipitate containing GZ with polymethyl-methacrylate (PMMA) were prepared. Four tablet formulations were prepared containing; a) GZ alone, b) GZ: PEG6000, 1:10, c) GZ:PMMA 1:3, and, d)both GZ:PEG6000 1:10 and GZ:PMMA 1:3. The solvent evaporation method showed more enhancement of GZ solubility than the melting one, and this solubilizing effect increased with PEG increment. Generally, PEG6000 showed more enhancement of dissolution than PEG4000 especially at 1:10 drug: polymer ratio (the most enhancing formula). Also, the prepared tablet formulations showed acceptable physical properties according to USP/NF requirements. The dissolution results revealed that tablets containing PEG6000 (1:10) have the most rapid release rate, followed by the formula containing both PEG6000 and PMMA, while that including PMMA alone showed the slowest dissolution rate. Moreover, In-vivo studies for each of the above four formulations, were performed using four mice groups. The most effective formula in decreasing the blood glucose level, through the first 6 hours, was that containing GZ and PEG6000, 1:10. However, formula containing the combination of enhanced and sustained GZ was the most effective in decreasing the blood glucose level through 16 hours. Successful in-vitro in-vivo correlations could be detected between the percent released and the percent decreasing of blood glucose level after 0.5 hours.


Author(s):  
Venu Madhav K ◽  
Somnath De ◽  
Chandra Shekar Bonagiri ◽  
Sridhar Babu Gummadi

Fenofibrate (FN) is used in the treatment of hypercholesterolemia. It shows poor dissolution and poor oral bioavailability after oral administration due to high liphophilicity and low aqueous solubility. Hence, solid dispersions (SDs) of FN (FN-SDs) were develop that might enhance the dissolution and subsequently oral bioavailability. FN-SDs were prepared by solvent casting method using different carriers (PEG 4000, PEG 6000, β cyclodextrin and HP β cyclodextrin) in different proportions (0.25%, 0.5%, 0.75% and 1% w/v). FN-SDs were evaluated solubility, assay and in vitro release studies for the optimization of SD formulation. Differential scanning calorimetry (DSC), powder X-ray diffraction (PXRD) and scanning electron microscopy (SEM) analysis was performed for crystalline and morphology analysis, respectively. Further, optimized FN-SD formulation evaluated for pharmacokinetic performance in Wistar rats, in vivo in comparison with FN suspension.  From the results, FN-SD3 and FN-SD6 have showed 102.9 ±1.3% and 105.5±3.1% drug release, respectively in 2 h. DSC and PXRD studies revealed that conversion of crystalline to amorphous nature of FN from FT-SD formulation. SEM studies revealed the change in the orientation of FN when incorporated in SDs. The oral bioavailability FN-SD3 and FN-SD6 formulations exhibited 2.5-folds and 3.1-folds improvement when compared to FN suspension as control. Overall, SD of FN could be considered as an alternative dosage form for the enhancement of oral delivery of poorly water-soluble FN.


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