Current Issue : April - June Volume : 2016 Issue Number : 2 Articles : 7 Articles
Formulating a drug into solid dispersion is an effective approach to enhance the dissolution and bioavailability of poorly soluble drugs. Solvent evaporation using a rotary evaporator is one of the most commonly used methods for laboratory scale preparation of solid dispersions. This work aimed to investigate the influence of different formulation and process variables on the properties of piroxicam (PXM) solid dispersions prepared using rotary evaporator. An 8-factor, 12-run Plackett- Burman design was employed for screening of 8 independent variables namely concentration of drug in the dispersion solution (A), type of carrier (B), type of solvent (C), concentration of carrier (D), concentration of lubricant (E), Stirring time (F), rotation speed during the evaporation process (G) and evaporation temperature (H). Saturation solubility (SS)(Y1) and dissolution efficiency at 15 min (% DE 15 min) (Y2) were selected as response variable (dependent variables). The regression models were significant and exhibited a good description for the responses. Factors A, B, D and H were found to exert significant influence on the solubility and dissolution of PXM from solid dispersions....
The poor aqueous solubility of drugs is a challenging problem faced by pharmaceutical scientists\nin drug formulation. Cosolvency and micellization techniques have been severally used to enhance\nthe solubility of poorly aqueous soluble drugs. Mirtazapine, a tetracyclic antidepressant used for\nthe treatment of moderate to severe depression and anxiety, has very poor aqueous solubility. The\nobjective of the study was to investigate the effect of solubilizing agents (cosolvents and surfactants)\non the aqueous solubility of mirtazapine while envisaging that any significant improvement\nin its aqueous solubility could contribute towards alleviating the withdrawal symptoms often associated\nwith the drug. The solubility of mirtazapine was determined at room temperature in\naqueous mixtures of cosolvents (propylene glycol and polyethylene glycol 400) and surfactants\n(polysorbate 20, polysorbate 80 and sodium lauryl sulfate). An exponential increase in mirtazapine\nsolubility was observed when total drug solubility in water-cosolvent system was plotted\nagainst cosolvent fraction volume. Polyethylene glycol 400 gave larger solubilization capacity ()\nwhen compared to propylene glycol. With the surfactants, linear relationship between the total\nsolubility of the drug in water-surfactant mixtures and surfactant concentration was noted. Sodium\nlauryl sulfate showed the largest solubilization power (k) when compared to the nonionic\nsurfactants (polysorbate 20 and polysorbate 80 respectively). A linear relationship between standard\nfree energy and partition coefficient was also observed. The result of the study shows that\naqueous solubility of mirtazapine is significantly improved by cosolvency and micellization and\ntherefore there exists the possibility of improving the withdrawal symptoms often experienced\nwith the drug. It also suggests that large free energy is required for drugs with high partition coefficients\nto permeate the biological membrane....
Microsphere-based controlled release technologies have been utilized for the long-term delivery of proteins,\npeptides and antibiotics, although their synthesis poses substantial challenges owing to formulation\ncomplexities, lack of scalability, and cost. To address these shortcomings, we used the electrospray process\nas a reproducible, synthesis technique to manufacture highly porous (>94%) microspheres while maintaining\ncontrol over particle structure and size. Here we report a successful formulation recipe used to generate\nspherical poly(lactic-co-glycolic) acid (PLGA) microspheres using the electrospray (ES) coupled with a novel\nthermally induced phase separation (TIPS) process with a tailored Liquid Nitrogen (LN2) collection scheme.\nWeshow how size, shape and porosity of resulting microspheres can be controlled by judiciously varying\nelectrospray processing parameters and we demonstrate examples in which the particle size (and porosity)\naffect release kinetics. The effect of electrospray treatment on the particles and their physicochemical properties\nare characterized by scanning electron microscopy, confocal Raman microscopy, thermogravimetric\nanalysis and mercury intrusion porosimetry. The microspheres manufactured here have successfully\ndemonstrated long-term delivery (i.e. 1 week) of an active agent, enabling sustained release of a dye with\nminimal physical degradation and have verified the potential of scalable electrospray technologies for an\ninnovative TIPS-based microsphere production protocol....
The objective of the present investigation was to develop and optimize immediate release pellet formulations of poorly soluble drug telmisartan (TLM) by liquid layering technique to enhance the solubility as well as bioavailability with sodium hydroxide as alkalizer and tween 80 as surfactant. In this study, a 32 full factorial design was employed to optimize the formulation of pellets. In order to optimize formulations, the amount of sodium hydroxide and the amount of tween 80, were chosen as independent variables while the cumulative % drug release at 10 minutes and 20 minutes were taken as dependant variables. The prepared pellets were evaluated for the parameters like flow properties, yield of the pellets, moisture content, friability, drug loading efficiency and in-vitro drug release. All the pellets exhibited good flow properties and the drug loading efficiency was also good. The optimized pellet formulation (F10) showed highest percent of drug release 99.84% by the end of 30 minutes. The optimized pellet formulation F10 was subjected to FT-IR, XRD and stability studies. The compatibility between drug and polymers in the drug-loaded pellets was confirmed by FT-IR studies. The pellet formulation was found to be stable under the tested conditions of storage. In vivo bioavailability studies indicated significance difference between TLM coated pellets and pure drug. Based on the results, the present study revealed that the dissolution as well as oral bioavailability of TLM could be improved by preparing immediate release TLM coated pellets....
L-ascorbic acid is a water soluble vitamin (vitamin C) widely used as an additive in foods and cosmetics.\nIt has high instability against certain environmental factors; the main cause of its deterioration\nis oxidation. Microencapsulation is an effective protection technique of L-ascorbic acid\nfrom its degradation reactions. This work is focused on the encapsulation of L-ascorbic acid by\nspray drying technique using sodium alginate as wall material. The microcapsules morphology\nwas observed by scanning electron microscopy (SEM) and the encapsulation efficiency was determined\nby spectrophotometric analysis. Results showed that encapsulation efficiency was of\n93.48% and after 30 days was of 92.55%; differences were not significant, so that the stability of\nL-ascorbic acid was not affected. Encapsulation yields obtained were low, at around 30%, but the\nmicrocapsules morphology obtained is spherical....
For poorly soluble, highly permeable (class II) drug meloxicam, the rate of oral absorption is often controlled by the dissolution rate in the gastrointestinal tract. The aim of the present study was to develop meloxicam spherical agglomerate to improve solubility characteristic and dissolution rate by neutralization method. Crystallization medium used for spherical agglomerates of meloxicam consisted of 1 N sodium hydroxide, 0.07M hydrochloric acid and chloroform as bridging liquid. In this method the crystallization takes place mainly due to the precipitation of drug by the addition of hydrochloric acid in which the drug is insoluble followed by agglomeration of crystal by the addition of bridging liquid under continuous stirring. The precipitated crystals were filtered and dried at 45°C for 24 hour. Process variables such as amount of chloroform, hydrochloric acid, stirring speed and stirring time were optimized. Micromeritic, solubility and dissolution studies were carried out. Dissolution profiles of the spherical agglomerates were compared with pure sample. Among the entire parameters batch obtained with 1 N sodium hydroxide, 0.07M HCl and chloroform (bridging liquid) in the ratio of 25:80:8 ml was optimum. The spherical agglomerates showed significant improvement in dissolution from a value 55.02% for pure meloxicam to 89.12%....
Theranostic nanomedicines are a promising new technological advancement toward personalized medicine.\nAlthough much progress has been made in pre-clinical studies, their clinical utilization is still under development.\nA key ingredient for successful theranostic clinical translation is pharmaceutical process design for production on\na sufficient scale for clinical testing. In this study, we report, for the first time, a successful scale-up of a model\ntheranostic nanoemulsion. Celecoxib-loaded near-infrared-labeled perfluorocarbon nanoemulsion was produced\non three levels of scale (small at 54 mL, medium at 270 mL, and large at 1,000mL) using microfluidization.\nThe average size and polydispersity were not affected by the equipment used or production scale. The overall\nnanoemulsion stability was maintained for 90 days upon storage and was not impacted by nanoemulsion production\nscale or composition. Cell-based evaluations show comparable results for all nanoemulsions with no significant\nimpact of nanoemulsion scale on cell toxicity and their pharmacological effects. This report serves as the\nfirst example of a successful scale-up of a theranostic nanoemulsion and a model for future studies on theranostic\nnanomedicine production and development....
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