scholarly journals Synthesis and Characterization of a New Norfloxacin/Resorcinol Cocrystal with Enhanced Solubility and Dissolution Profile

Pharmaceutics ◽  
2021 ◽  
Vol 14 (1) ◽  
pp. 49
Author(s):  
Hanan Fael ◽  
Rafael Barbas ◽  
Rafel Prohens ◽  
Clara Ràfols ◽  
Elisabet Fuguet

A new cocrystal of Norfloxacin, a poorly soluble fluoroquinolone antibiotic, has been synthetized by a solvent-mediated transformation experiment in toluene, using resorcinol as a coformer. The new cocrystal exists in both anhydrous and monohydrate forms with the same (1:1) Norfloxacin/resorcinol stoichiometry. The solubility of Norfloxacin and the hydrated cocrystal were determined by the shake-flask method. While Norfloxacin has a solubility of 0.32 ± 0.02 mg/mL, the cocrystal has a solubility of 2.64 ± 0.39 mg/mL, approximately 10-fold higher. The dissolution rate was tested at four biorelevant pH levels of the gastrointestinal tract: 2.0, 4.0, 5.5, and 7.4. In a first set of comparative tests, the dissolution rate of Norfloxacin and the cocrystal was determined separately at each pH value. Both solid forms showed the highest dissolution rate at pH 2.0, where Norfloxacin is totally protonated. Then, the dissolution rate decreases as pH increases. In a second set of experiments, the dissolution of the cocrystal was evaluated by a unique dissolution test, in which the pH dynamically changed from 2.0 to 7.4, stepping 30 min at each of the four biorelevant pH values. Results were quite different in this case, since dissolution at pH 2 affects the behavior of Norfloxacin at the rest of the pH values.

Author(s):  
D. Nagasamy Venkatesh ◽  
S. Karthick ◽  
M. Umesh ◽  
G. Vivek ◽  
R.M. Valliappan ◽  
...  

Roxythromycin/ β-cyclodextrin (Roxy/ β-CD) dispersions were prepared with a view to study the influence of β-CD on the solubility and dissolution rate of this poorly soluble drug. Phase-solubility profile indicated that the solubility of roxythromycin was significantly increased in the presence of β-cyclodextrin and was classified as AL-type, indicating the 1:1 stoichiometric inclusion complexes. Physical characterization of the prepared systems was carried out by differential scanning calorimetry (DSC), X-ray diffraction studies (XRD) and IR studies. Solid state characterization of the drug β-CD binary system using XRD, FTIR and DSC revealed distinct loss of drug crystallinity in the formulation, ostensibly accounting for enhancement of dissolution rate.


2012 ◽  
Vol 4 (2) ◽  
pp. 58-62
Author(s):  
Aparajita Malakar ◽  
Bishwajit Bokshi ◽  
Utpal Kumar Karmakar

The aim of the present study was to increase the solubility of a poorly water soluble BCS class II drug, valsartan. Liquisolid technology and solid dispersion by kneading method were techniques used to improve the solubility of the drug by using non-volatile solvents and some hydrophilic carriers. Liquisolid compacts were prepared by dissolving the drug in suitable non volatile solvents. The various non volatile solvents used were PG, PEG, and glycerine. The carrier coating materials play an important role in improving the solubility of the drug. The dissolution rate of the drug was increased by using propylene glycol as non-volatile solvent at 20:1 ratio of carrier to coating material. Solid dispersion by kneading method were another attempt to improve solubility the various carrier materials used were PVP K 30, PEG 6000 and mannitol, these carriers are used in various ratios to improve its solubility. The dissolution rate of drug using solid dispersion kneading method with mannitol was increased at 1:3 ratio. The DSC and FTIR studies revealed no drug excipients interactions, whereas XRD revealed the reduced crystalinity of drug, which showed enhanced solubility. From the results it was concluded that the liquisolid compacts enhanced the solubility of valsartan in comparison to traditional solid dispersion method.DOI: http://dx.doi.org/10.3329/sjps.v4i2.10441  S. J. Pharm. Sci. 4(2) 2011: 58-62


2011 ◽  
Vol 61 (4) ◽  
pp. 391-402 ◽  
Author(s):  
Lim Lyn ◽  
Huan Sze ◽  
Adhiyaman Rajendran ◽  
Gorajana Adinarayana ◽  
Kamal Dua ◽  
...  

Crystal modifications and dissolution rate of piroxicam Piroxicam is a nonsteroidal anti-inflammatory drug with low aqueous solubility which exhibits polymorphism. The present study was carried out to develop polymorphs of piroxicam with enhanced solubility and dissolution rate by the crystal modification technique using different solvent mixtures prepared with PEG 4000 and PVP K30. Physicochemical characteristics of the modified crystal forms of piroxicam were investigated by X-ray powder diffractometry, FT-IR spectrophotometry and differential scanning calorimetry. Dissolution and solubility profiles of each modified crystal form were studied and compared with pure piroxicam. Solvent evaporation method (method I) produced both needle and cubic shaped crystals. Slow crystallization from ethanol with addition of PEG 4000 or PVP K30 at room temperature (method II) produced cubic crystal forms. Needle forms produced by method I improved dissolution but not solubility. Cubic crystals produced by method I had a dissolution profile similar to that of untreated piroxicam but showed better solubility than untreated piroxicam. Cubic shaped crystals produced by method II showed improved dissolution, without a significant change in solubility. Based on the XRPD results, modified piroxicam crystals obtained by method I from acetone/benzene were cube shaped, which correlates well with the FTIR spectrum; modified needle forms obtained from ethanol/methanol and ethanol/acetone showed a slight shift of FTIR peak that may be attributed to differences in the internal structure or conformation.


2016 ◽  
Vol 15 (4) ◽  
pp. 170-176 ◽  
Author(s):  
Pavan Kommavarapu ◽  
Arthanareeswari Maruthapillai ◽  
Kamaraj Palanisamy

Author(s):  
SURESH GAUTAM ◽  
YOGESH NIKALAJE ◽  
DARSHANA BHADRE ◽  
RASHMI TRIVEDI ◽  
MILIND UMEKAR ◽  
...  

Objective: Epilepsy is a common neurodegenerative disorder characterized by spontaneous and repeated attacks of convulsions. It requires immediate pharmacotherapy to prevent its progression to status epilepticus. However, most of the anticonvulsant drugs are poorly water-soluble and demonstrate the delayed onset of action. Thus there is a need to improve its solubility for the better pharmaceutical profile. The objective of the present investigation was to enhance the solubility of lamotrigine incorporating soya lecithin as a phospholipid carrier by solid dispersion technique Methods: Solid dispersions of lamotrigine were prepared with soya lecithin by the solvent method. The effect of concentration of phospholipid and solvents on aqueous solubility and dissolution profile of lamotrigine was analyzed. Results: Ethanol increased lamotrigine solubility with soya lecithin in ratio 5:1. X-ray diffraction and scanning electron micrograph indicated a smaller crystallite size of lamotrigine with fairly uniform size distribution in the lamotrigine-soya lecithin solid dispersion. The resultant solid dispersion also significantly delayed the onset of clonic convulsion (875.8 s) as compared to control (85.5 s) and offered complete protection (100%) against the pentylenetetrazole induced seizures in the rat as compared to control (33.33%). Also, solid dispersion with maximum drug content (77.68%) and dissolution rate (91.40%) was formulated as an orodispersible tablet and characterized for its pharmaceutical properties. Conclusion: It can be concluded that the solid dispersion of lamotrigine incorporated with soya lecithin demonstrated enhanced solubility and dissolution rate may have potential clinical application.


2010 ◽  
Vol 10 (3) ◽  
pp. 234-238 ◽  
Author(s):  
Alija Uzunović ◽  
Edina Vranić ◽  
Šeherzada Hadžidedić

Carbamazepine belongs to the class II biopharmaceutical classification system (BCS) which is characterized by a high per-oral dose, a low aqueous solubility and a high membrane permeability. The bioavailability of such a drug is limited by the dissolution rate. The present study deals with the formulations of immediate release tablets of poorly soluble carbamazepine. As model tablets for this investigation, two formulations (named “A” and “B” formulations) of carbamazepine tablets labeled to contain 200 mg were evaluated. The aim of this study was to establish possible differences in dissolution profile of these two formulations purchased from the local market.The increased crystallinity together with enlarged particle size, enhanced aggregation and decreased wettability of the drug, resulted in insufficient dissolution rate for formulation “B’.’ From the dissolution point of view, this formulation was inferior to the formulation “A, due to the solubilization effect.


2021 ◽  
Vol 3 (1) ◽  
pp. 19-28
Author(s):  
Gina Alina Catrina ◽  
◽  
Bogdan Stanescu ◽  
Agnes Serbanescu ◽  
Georgiana Cernica ◽  
...  

Long-term landfilling of hazardous waste should be a careful choice for any producer or generator of waste, as the behavior of the waste is different due to the physical-chemical conditions or following contact with other hazardous waste. In this study, the research undertaken was aimed at developing an experimental method for the assessment and characterization of hazardous waste for long-term storage. The method consists in the assessment of the behavior of heavy metals from waste, under different leaching conditions. To study various hazardous wastes, fly ash from the incineration of medical waste and slag from aluminum casting were chosen. Contact time, pH and redox potential are important parameters in the leaching process. The solubility of metals increases at pH values between 2 - 5 pH units and decreases at pH values between 6-12 pH units. The highest solubility of metals (As, Cr, Cu, Ni, Pb and Zn) in the tested waste was obtained after 48 hours at pH values between 2 - 5 pH units. Also, the values of the redox potential decrease almost linearly as the pH value increases. The developed method is a useful tool to assess the behavior of hazardous waste for long-term storage in landfills for this category of wastes.


2012 ◽  
Vol 583 ◽  
pp. 391-394 ◽  
Author(s):  
Qiang Zhang ◽  
Li Qin You ◽  
Chun Shan Zhu

The β-CD/NIPAAm-SA microspheres with temperature and pH sensibility were synthesized with β-cyclodextrin(β-CD), N-isopropylacrylamide(NIPAAm) and succinic anhydride(SA), and their drug-releasing properties were investigated. SEM showed that the β-CD/NIPAAm-SA microspheres had a good sphericity and a grain size of 200-300µm.And the swelling results indicated that the swelling rate was decreased with temperature raising and increased with pH value improving, and the phase transition volume changed suddenly at the temperature of about 27°C and 38°C, and the pH values of about 1.4 and 7.4. It revealed that the β-CD/NIPAAm-SA microspheres had pH and temperature sensibilities.


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