Enhancing the aqueous solubility and dissolution of olanzapine using freeze-drying

The aim of the present study was to develop an olanzapine freeze-dried tablet (FDT). The solubility and dissolution rate of poorly water-soluble olanzapine was improved by preparing a freeze-dried tablet of olanzapine using the freeze-drying technique . The FDT was prepared by dispersing the drug in an aqueous solution of highly water-soluble carrier materials consisting of gelatin, glycine, and sorbitol. The mixture was poured in to the pockets of blister packs and then was subjected to freezing and lyophilisation. The FDT was characterised by DSC, XRD and SEM and was evaluated for saturation solubility and dissolution. The samples were stored in a stability chamber to investigate their physical stability. Results obtained by DSC and X-ray were analysed and showed the crystalline state of olanzapine in FDT transformation to the amorphous state during the formation of FDT. Scanning electron microscope (SEM) results suggest reduction in olanzapine particle size. The solubility of olanzapine from the FDT was observed to be nearly four and a half times greater than the pure drug. Results obtained from dissolution studies showed that olanzapine FDT significantly improved the dissolution rate of the drug compared with the physical mixture (PM) and the pure drug. More than 90% of olanzapine in FDT dissolved within 5 minutes, compared to only 19.78% of olanzapine pure drug dissolved over the course of 60 minutes. In a stability test, the release profile of the FDT was unchanged, as compared to the freshly prepared FDT after 90 days of storing.O objetivo do presente estudo foi desenvolver comprimidos liofilizados de olanzapina (FDT). A solubilidade e a taxa de dissolução da olanzapina, fracamente solúvel em água, foram melhoradas com a preparação de comprimidos liofilizados de olanzapina usando a técnica de liofilização. O FDT foi preparado por dispersão do fármaco em solução aquosa de materiais altamente solúveis em água, como gelatina, glicina e sorbitol. A mistura foi colocada em blisters e, então, submetida ao congelamento e liofilização. O FDT foi caracterizado por DSC, Difração de Raios X e microscopia eletrônica de varredura(SEM) e avaliaram-se a solubilidade de saturação e a dissolução. As amostras for5am armazenadas em câmara de estabilidade para investigar a estabilidade física. Os resultados obtidos com DSC e Raios X foram analisados e mostraram a transformação do estado cristalino da olanzepina em FDT no estado amorfo durante a formação do FDT. Os resultados da SEM sugerem a redução do tamanho das partículas de olanzapina. A solubilidade da olanzapina do FDT melhorou significativamente a taxa de dissolução do fármaco comparativamente à mistura física (PM) e ao fármaco puro. Mais do que 90% da olanzepina no FDT dissolveu em 5 minutos, comparativamente aos 19,78% do fármaco puro dissolvido em 60 minutos. No teste de estabilidade, o perfil de liberação da FDT mostrou-se inalterado, quando comparado com o FDT recém-preparado, após 90 dias de armazenamento

Preparation and characterization of spherical agglomerates of piroxicam

The purpose of the present study was to prepare spherical agglomerates (SA) of piroxicam by solvent change method. Crystallization medium used for spherical agglomerates of piroxicam consisted of DMF:water and chloroform. The presence of solvents residual in SA was determined by gas chromatography and were particles were characterized by DSC, FT-IR, XRD and SEM. The respective solubility study and dissolution behavior studies were carried out. The samples were stored in stability chamber to investigate their physical stabilities. Solvents residuals in SA were found to be within the limits and exhibited decreased crystallinity of piroxicam in SA than pure piroxicam. The solubility and dissolution of the spherical agglomerates was improved compared with pure piroxicam and recrystallized sample. In stability test, the release profile of the spherical agglomeration was almost unchanged as compared with the freshly prepared spherical agglomeration stored at 20 °C and 45 % relative humidity for 90 days. Hence this technique can be used to obtain modified drug raw material for formulation of tablets of piroxicam by direct compression with directly compressible tablet excipients.Colegio de Farmacéuticos de la Provincia de Buenos Aire

ENHANCING SOLUBILITY AND DISSOLUTION OF FENOFIBRATE BY SPRAY DRYING TECHNIQUE

Objective: Fenofibrate, a hypolipidemic drug agent, exhibits poor water solubility and dissolution. Thus, the aim of the present study was to improve the solubility and dissolution rate of Fenofibrate by preparing microspheres by spray drying technique using Pluronic F-127.Methods: Fenofibrate Microspheres containing different ratios of Pluronic F-127 were produced by spray drying using Chloroform as solvent to enhance solubility and dissolution rate. The prepared formulations containing different ratios of drug and Pluronic F-127were evaluated for solubility and in-vitro dissolution. The prepared formulations were characterized by DSC, FT-IR, XRD and SEM. Dissolution profile of the prepared spray dried microspheres was compared with its physical mixture and the pure sample.Results: Spray dried microspheres exhibited decreased crystallinity. The solubility of microspheres containing Fenofibrate and Pluronic F-127(1:3w/w) exhibited three tenfold increases than the commercial Fenofibrate and dissolution of the same ratio microsphere showed 99 % release in 40 min. While same composition in physical mixture showed 37% release in 20 min.Conclusion: Consequently, from the above result it can be concluded that spray dried microspheres of Fenofibrate is a useful technique to improve the solubility and dissolution of poor water soluble drug like Fenofibrate

IMPROVEMENT OF THE SOLUBILITY AND DISSOLUTION OF TOLFENAMIC ACID USING LYOPHILIZATION TECHNIQUE

Abstract: The aim of the present study was to prepare freeze dried crystals (FD) of Tolfenamic acid (TA) by freeze drying technique. Crystallization medium used for freeze drying of Tolfenamic acid consisted of N,N-dimethylformamide (DMF) and Water as solvent systems. The presence of solvents residuals in FD was determined by Gas chromatography and particles were characterized by DSC, FT-IR, XRD and SEM. The respective solubility study and dissolution behaviour studies were carried out. The samples were stored in stability chamber to investigate their physical stabilities. Residual Solvents in FDs were found to be within the limit and exhibited decreased crystallinity as well solubility and dissolution of the Freeze dried crystals was improved than commercial sample of Tolfenamic acid. In stability study, it was found that physical properties and release profile of the freeze dried crystals was unaffected for 3 months. Hence this technique can be used to obtain modified drug raw material for formulation of tablets of Tolfenamic acid by direct compression with directly compressible tablet excipients

First Results from MFOSC-P : Low Resolution Optical Spectroscopy of a Sample of M dwarfs within 100 parsecs

Mt. Abu Faint Object Spectrograph and Camera (MFOSC-P) is an in-house developed instrument for Physical Research Laboratory (PRL) 1.2m telescope at Mt. Abu India, commissioned in February 2019. Here we present the first science results derived from the low resolution spectroscopy program of a sample of M Dwarfs carried out during the commissioning run of MFOSC-P between February-June 2019. M dwarfs carry great significance for exoplanets searches in habitable zone and are among the promising candidates for the observatory's several ongoing observational campaigns. Determination of their accurate atmospheric properties and fundamental parameters is essential to constrain both their atmospheric and evolutionary models. In this study, we provide a low resolution (R$\sim$500) spectroscopic catalogue of 80 bright M dwarfs (J$<$10) and classify them using their optical spectra. We have also performed the spectral synthesis and $\chi^2$ minimisation techniques to determine their fundamental parameters viz. effective temperature and surface gravity by comparing the observed spectra with the most recent BT-Settl synthetic spectra. Spectral type of M dwarfs in our sample ranges from M0 to M5. The derived effective temperature and surface gravity are ranging from 4000 K to 3000 K and 4.5 to 5.5 dex, respectively. In most of the cases, the derived spectral types are in good agreement with previously assigned photometric classification.Comment: Accepted for Publication in MNRA

International Journal of Pharmacy and Life Science. How to cite this article

Abstract Mefenamic acid, an anti-inflammatory drug, exhibits poor water solubility and flow properties. Spherical agglomerates were prepared by neutralization method. Crystallization medium used for spherical agglomerates of Mefenamic acid consisted of 1 M Sodium hydroxide; 0.7 M hydrochloric acid; iso propyl acetate (bridging liquid) in the ratio of 20:280:15, respectively. Spherical agglomerates were characterized by differential scanning calorimetry, Infrared spectroscopy, X-ray diffractometry and scanning electron microscopy. Micromeritic and dissolution behavior studies were carried out. Process variables such as amount of bridging liquid, stirring time and duration of stirring were optimized. Dissolution profile of the spherical agglomerates was compared with pure sample and recrystallized sample. Spherical agglomerates exhibited decreased crystallinity and improved micromeritic properties. The dissolution of the spherical agglomerates was improved compared with pure sample

Stabilizing Anionic Redox and Tuning Its Extent in Na-Rich Cathode Materials through Electronic Structure Engineering

The capacity of sodium-ion batteries (SIBs) can be enhanced by incorporating anionic redox into Na-rich cathode materials. However, excessive participation of oxygen in the redox process during the cycling often leads to several undesired issues including oxygen release. In this study, using first-principles computational methods through a systematic investigation and detailed analysis, we demonstrate an electronic structure tuning strategy through the aliovalent doping method to tune the amount of anionic redox in SIBs. Furthermore, we provide a method for achieving reversible anionic redox and emphasize that reversible anionic redox is not solely dependent on the covalent interaction between the transition metal and oxygen but is influenced by multiple factors that govern the electronic structure of the material. Using the aforementioned strategy, we identify an Al-doped Na-rich material, Na2Ru0.5Al0.5O3, which exhibits reversible cationic and anionic redox. Additionally, we rationalize the dominance of cationic redox in pristine Na2RuO3

Effect of Different Crystallization Techniques on the Dissolution Behavior of Ketoprofen

Purpose: To enhance the solubility and dissolution characteristics of ketoprofen using various crystallization techniques. Methods: Ketoprofen crystals were prepared by various crystallization technique including spherical agglomeration (SA), spray drying (SD), freeze drying (FD) and super cooling (SC). The crystallization medium used for all the techniques consisted of water and chloroform. Residual solvents in the crystals were determined and the crystals were characterized by DSC, FT-IR, XRD and SEM. Both solubility and dissolution behavior studies were carried out. The physical stability of the crystals were also evaluated after storage over a period of time. Results: Residual IPA and chloroform in the crystals ranged from 4.10 - 5.70 and 1.84 - 2.57 ppm, respectively, which are well below their toxic limits. The crystals obtained exhibited lower crystallinity than the original drug. The solubility of FD crystals in water increased almost fivefold to 0.0926 mg/ml compared with that of the drug (0.0172 mg/ml), while the dissolution rates of the developed crystals were than that of the original crystals. For example, FD crystals demonstrated the highest dissolution (99.9 %) compared with original crystals (64.3 %). In the stability test, the dissolution profiles of the developed crystals remained largely unchanged over the period of the stability study. Conclusion: The re-crystallization techniques used in this study can be applied to obtain modified ketoprofen for formulation of tablets of the drug with improved drug dissolution