scholarly journals Physicochemical characterization and in vitro dissolution behavior of olanzapine-mannitol solid dispersions

2012 ◽  
Vol 48 (2) ◽  
pp. 243-255 ◽  
Author(s):  
Venkateskumar Krishnamoorthy ◽  
Suchandrasen ◽  
Verma Priya Ranjan Prasad

The objective of the present work is to study the dissolution behavior of olanzapine from its solid dispersions with mannitol. Solid dispersions were prepared by melt dispersion method and characterized by phase solubility studies, drug content and in vitro dissolution studies. The best releasing dispersions were selected from release data, dissolution parameters and their release profiles. Solid state characterization techniques like Fourier transform infrared (FT-IR) spectroscopy, X-ray diffractometry, differential scanning calorimetry, near-infrared and Raman spectroscopy were used to characterize the drug in selected dispersions. The dispersions were also evaluated by wettability studies and permeation studies. The results of phase solubility studies and the thermodynamic parameters indicated the spontaneity and solubilization effect of the carrier. The release study results showed greater improvement of drug release from solid dispersions compared to pure drug, and the release was found to increase with an increase in carrier content. The possible mechanism for increased release rate from dispersions may be attributed to solubilization effect of the carrier, change in crystal quality, phase transition from crystalline to amorphous state, prevention of agglomeration or aggregation of drug particles, change in surface hydrophobicity of the drug, and increased wettability and dispersability of the drug in dissolution medium. The suggested reasons for increased release rate from dispersions were found to be well supported by results of solid state characterization, wettability and permeation studies. The absence of any interaction between the drug and the carrier was also proved by FT-IR analysis.

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.   


Pharmaceutics ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 548 ◽  
Author(s):  
Serena Bertoni ◽  
Beatrice Albertini ◽  
Nadia Passerini

Delivery of poorly water soluble active pharmaceutical ingredients (APIs) by semi-crystalline solid dispersions prepared by spray congealing in form of microparticles (MPs) is an emerging method to increase their oral bioavailability. In this study, solid dispersions based on hydrophilic Gelucires® (Gelucire® 50/13 and Gelucire® 48/16 in different ratio) of three BCS class II model compounds (carbamazepine, CBZ, tolbutamide, TBM, and cinnarizine, CIN) having different physicochemical properties (logP, pKa, Tm) were produced by spray congealing process. The obtained MPs were investigated in terms of morphology, particles size, drug content, solid state properties, drug-carrier interactions, solubility, and dissolution performances. The solid-state characterization showed that the properties of the incorporated drug had a profound influence on the structure of the obtained solid dispersion: CBZ recrystallized in a different polymorphic form, TBM crystallinity was significantly reduced as a result of specific interactions with the carrier, while smaller crystals were observed in case of CIN. The in vitro tests suggested that the drug solubility was mainly influenced by carrier composition, while the drug dissolution behavior was affected by the API solid state in the MPs after the spray congealing process. Among the tested APIs, TBM-Gelucire dispersions showed the highest enhancement in drug dissolution as a result of the reduced drug crystallinity.


2011 ◽  
Vol 47 (3) ◽  
pp. 513-523 ◽  
Author(s):  
Jagdale Swati Changdeo ◽  
Musale Vinod ◽  
Kuchekar Bhanudas Shankar ◽  
Chabukswar Anuruddha Rajaram

Allopurinol is a commonly used drug in the treatment of chronic gout or hyperuricaemia associated with treatment of diuretic conditions. One of the major problems with the drug is that it is practically insoluble in water, which results in poor bioavailability after oral administration. In the present study, solid dispersions of allopurinol were prepared by solvent evaporation, kneading method, co-precipitation method, co-grinding method and closed melting methods to increase its water solubility. Hydrophilic carriers such as polyvinylpyrrolidone, polyethylene glycol 6000 were used in the ratio of 1:1, 1:2 and 1:4 (drug to carrier ratio). The aqueous solubility of allopurinol was favored by the presence of both polymers. These new formulations were characterized in the liquid state by phase solubility studies and in the solid state by differential scanning calorimetry, powder X-ray diffraction, UV and Fourier Transform Infrared spectroscopy. Solid state characterizations indicated that allopurinol was present as an amorphous material and entrapped in polymer matrix. In contrast to the very slow dissolution rate of pure allopurinol, the dispersion of the drug in the polymers considerably enhanced the dissolution rate. Solid dispersion prepared with polyvinylpyrrolidone showed highest improvement in wettability and dissolution rate of allopurinol. Mathematical modeling of in vitro dissolution data indicated the best fitting with Korsemeyer-Peppas model and the drug release kinetics primarily as Non-Fickian diffusion. Therefore, the present study showed that polyvinylpyrrolidone and polyethylene glycol 6000 have a significant solubilizing effect on allopurinol.


2017 ◽  
Vol 16 (10) ◽  
pp. 2359-2364
Author(s):  
Zwanden Sule Yahaya ◽  
Kenneth C. Ofokansi ◽  
Suzane T. Allagh ◽  
Pat G. Bhatia

Purpose: To investigate experimentally the inclusion of artemether into the cavity of  hydroxypropyl-β-cyclodextrin and examine its effect on the solubility and dissolution rate of the drug.Methods: Inclusion complexes of artemether with hydroxypropyl-β-cyclodextrin of molar ratios 1:1, 1:2 and 1:3 were prepared using the kneading method. Phase solubility analysis and in vitro dissolution studies were utilized in evaluating the influence of inclusion complex formation on the solubility and dissolution rate of the drug. The complexes were characterized using differential scanning calorimetry (DSC) and Fourier transform infrared spectroscopy (FT-IR). The inclusion complex containing equimolar concentrations of artemether and hydroxypropyl-β-cyclodextrin was then formulated into tablets via direct compression and  evaluated for various pharmaceutical characteristics including hardness, friability, absolute drug content and comparative in vitro dissolution profiles with some  commercially available brands of artemether.Results: The phase solubility diagram for the formed complexes in water at 37 oC indicated a linear curve soluble complex system (referred to as the AL system), and a stability constant (KC) value of 143 M-1. Evidence consistent with inclusion complex formation was obtained using FT-IR and DSC. The formulated inclusion complex tablets exhibited a higher rate of dissolution than the pure drug and commercial brands, showing 3.9-, 1.8- and 1.6-fold increases, respectively, over a period of 15 min.Conclusion: Inclusion complexation of artemether with hydroxypropyl-β-cyclodextrin is a promising approach to enhance the solubility and dissolution rate of the drug.Keywords: Artemether, 2-Hydroxypropyl-β-cyclodextrin, Dissolution, Solubility enhancement, Inclusion complex


INDIAN DRUGS ◽  
2016 ◽  
Vol 53 (01) ◽  
pp. 54-59
Author(s):  
S. S Shelake ◽  
◽  
R. G Gaikwad ◽  
S Patil ◽  
F. I. Mevekari ◽  
...  

Crystalline state compounds are typically dissolution rate limited and dissolution rate is directly proportional to the solubility for BCS class II or class IV compounds. Solid dispersions are one of the most promising strategies to improve the oral bioavailability poorly water soluble drugs. The purpose of this study was to increase solubility of carvedilol by solid dispersion (SDs) technique with Poloxamer (PXM) 407 in aqueous media. The carvedilol- PXM 407 solid dispersion was prepared by solvent evaporation, kneading and melting method. It was characterized by differential scanning calorimetry (DSC), X-ray powder diffraction (XRD), Fourier transformation infra-red spectroscopy (FT-IR), scanning electron microscopy (SEM) and in vitro dissolution studies. The prepared solid dispersion were found to have higher dissolution rates as compared to intact carvedilol. During formulation of solid dispersion crystalline to amorphous transition has been observed.


2020 ◽  
Vol 23 (1) ◽  
pp. 44-53
Author(s):  
Sharmin Akhter ◽  
AKM Saif Uddin ◽  
Aninda Kumar Nath ◽  
Md Salahuddin ◽  
Mohammad Fahim Kadir ◽  
...  

Ketoprofen [2-(3-benzoylphenyl)-propionic acid], a non-steroidal anti-inflammatory drug exhibits poor dissolution pattern. Solid dispersion (SD) techniques were used because it is particularly promising to improve the oral absorption and bioavailability of BCS Class II drugs. This investigation entails solid dispersion of ketoprofen which was formulated and characterized for better release profile and immediate action of the drug. Melting method was applied to prepare solid dispersion by using two immediate release (IR) polymer PEG 6000 and HPMC 6 cps at different weight ratios. In the formulation, a fixed amount of lactose was used as adsorbent. The solid dispersions were investigated for drug entrapment efficiency and dissolution behavior. In vitro dissolution study was performed in phosphate buffer (pH 7.4) medium for one hour. Percent cumulative drug release from solid dispersion was found to be minimum 92.19% and maximum 98.95% within one hour, which showed a better dissolution compared to the active drugs. Evaluation of the properties of the solid dispersion was also performed by using Scanning Electron Microscopy (SEM) study and Differential Thermal Analysis (DTA). SEM results indicated that ketoprofen crystallinity in SDs was significantly reduced, and that the majority of ketoprofen was in amorphous form. No interaction was found between drug and polymers from DTA and Fourier-transform infrared (FTIR) spectroscopy analysis. So, solid dispersion technique may be an effective technique to enhance dissolution rate of ketoprofen. Bangladesh Pharmaceutical Journal 23(1): 44-53, 2020


2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Elahe Faraji ◽  
Mojdeh Mohammadi ◽  
Mohammad Mehdi Mahboobian

The object of this study was to prepare binary and ternary solid dispersions of atorvastatin (ATR) by the melting method using PEGs and poloxamer 188 (P188) as the carriers, singly and in combination with each other. Dissolution behavior, solubility studies, X-ray diffractometry, differential scanning calorimetry, and Fourier transform infrared spectroscopy were studied. Furthermore, antihyperlipidemic activities of formulations were compared to each other by serum lipid analyses in hyperlipidemic rats. Based on the results, the highest dissolution efficiency ( DE 30 = 83 % ) was obtained by binary systems consisted of ATR and P188. Also, no additional improvement was observed in dissolution properties of ternary solid dispersion formulations. Solubility studies showed enhancement of ATR phase solubility in water and a buffer solution containing P188 or PEG 10000. Furthermore, saturated solubility of ATR in the buffer solution improved more than twofold in the optimized ternary dispersion system. No crystalline changes occurred in PEG-based formulations; meanwhile, partial amorphization happened in the ATR-P188 combination. Finally, the in vivo study in hyperlipidemic rats exhibited a rapid decrease in the lipid profile of all formulations compared to ATR (after 7 days). Moreover, reduction of serum triglycerides and total cholesterol on the 14th day in the ATR group ( p value < 0.01) was less than solid dispersion or physical mixing preparations ( p value < 0.001). These findings proved the appropriate influence of using PEG and P188 in solid dispersion systems for the improvement of the therapeutic efficiency of ATR.


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