Preparation of acetazolamide composite microparticles by supercritical anti-solvent techniques

Duarte, Ana Rita C.; Roy, Christelle; Vega‐González, Arlette; Duarte, Isabel Catarina; Subra‐Paternault, Pascale

doi:10.1016/j.ijpharm.2006.09.041

Cited by 52 publications

(29 citation statements)

References 13 publications

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“…These may be forming immediately due to the affinity dissolution of the pore former, which facilitates the inflow of media into the tablet to dissolve the tablet components and generate the osmotic pressure. Eudragit RSPO is insoluble in aqueous media and has low permeability while Eudragit RLPO is insoluble and has high permeability [35] . Both polymers exhibit pH independent swelling.…”

Section: Resultsmentioning

confidence: 99%

Design and Pharmacodynamic Evaluation of Optimized Microporous Osmotic Tablets of Venlafaxine Hydrochloride

Monica¹,

Shilpa²,

Swati³

et al. 2017

Journal of Pharmaceutical Sciences

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Monica, et al.: Microporous Osmotic Tablets of Venlafaxine HydrochlorideMicroporous osmotic tablets were developed using controlled porosity membrane, which delivers drug in a controlled manner for prolonged period of time. The objective of the present investigation was to formulate and evaluate an oral osmotic drug delivery system for the antidepressant drug venlafaxine hydrochloride to achieve zero order release. Venlafaxine hydrochloride was selected as it has a short biological half-life and high aqueous solubility. Drug-excipient compatibility was studied using Fourier transform infrared spectroscopy. Core tablets were prepared by wet granulation method followed by coating. Sodium chloride and potassium chloride (1:1) were used as osmotic agents in the core tablet and polymers Eudragit RLPO and RSPO (1:1) were used for coating along with sorbitol (70% w/w) as pore formers. The tablets showed desired sustained release profile for 24 h. Optimization studies were performed to study the effect of concentration of osmotic agent and pore former on drug release (t 50% and t 90% ). From in vitro release studies, it was evident that drug release was independent of dissolution media, agitation intensity, but highly dependent on the concentration of pore forming agents, osmotic agent and weight gain of the tablet coating. Scanning electron microscopy confirmed the microporous structure of optimized batch. The optimized formulation gave desired once a day release of venlafaxine hydrochloride without using laser drilling technique, which would make it more patient compliant and cost effective.

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Section: Resultsmentioning

confidence: 99%

Design and Pharmacodynamic Evaluation of Optimized Microporous Osmotic Tablets of Venlafaxine Hydrochloride

Monica¹,

Shilpa²,

Swati³

et al. 2017

Journal of Pharmaceutical Sciences

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“…15,16) However, some types of drugs grow very fast in anti-solvent, and thus, it was difficult to produce nano-sized drug particles in the beaker using the anti-solvent method alone. In such a case, the spray nozzle that we developed could be more effective because these suspensions were spray-dried immediately and produced microparticles before crystallization began.…”

Section: Preparation Of Ec/man Microspheres Using a Two-solution Miximentioning

confidence: 99%

Development of a Novel and Customizable Two-Solution Mixing Type Spray Nozzle for One-Step Preparation of Nanoparticle-Containing Microparticles

Ozeki

Akiyama

Takahashi

et al. 2012

Biological & Pharmaceutical Bulletin

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Production of drug nanoparticles is an effective strategy to enhance solubility and oral absorption of water-insoluble drugs. The handling of drug nanoparticles has been an important issue in drug formulation because nanoparticles easily aggregate each other and redispersion of these particles is very difficult. In the present study, we developed a unique two-solution mixing type spray nozzle that can prepare drug nanoparticles in microparticles in one step without any common solvent and surfactant, and then, the prepared formulation were evaluated. Ethylcellulose (EC) and mannitol (MAN) were used as a model polymer of water-insoluble compound and a water-soluble carrier, respectively. We characterized the EC/MAN microparticles produced by the novel spray nozzle when customizing the nozzle parts to mix EC and MAN solution. Relatively smaller EC nanoparticles (<110 nm) in MAN microparticles (approximately 3 µm) were obtained by changing the customizable parts in the nozzle. In addition, the core of EC nanoparticles (<50 nm) was also observed by atomic force microscopy. We also found that the mixing time in the nozzle parts affected the size and the standard deviation of EC nanoparticles. These results suggest that the size of EC nanoparticles in MAN microparticles is controllable by using this unique nozzle. After all, we could prepare MAN microparticles containing EC nanoparticles in one step by using the novel nozzle. The drug/MAN microparticles formulation produced by the nozzle may be useful for the handling of drug nanoparticles.Key words two-solution mixing type nozzle; spray drier; composite particle; anti-solvent effect; one-step preparation Improvement of water-insoluble drugs has been an important issue as increasing the promising drug candidates. The use of nano-sized drugs is an effective strategy to enhance drug solubility.1-5) Several methods have been extensively employed to prepare smaller particles from large drug particles, such as the use of ball and jet mills, crystallization by evaporating the drug in an organic solvent, and preparation of emulsions and liposomes. Although these methods have advantages and disadvantages, the handling of nano-sized drug powders has been an important factor. Nanoparticles can easily aggregate with each other because of their great surface energy; hence, redispersion of these aggregates is very difficult and the effective properties derived from nanoparticles are lost. Therefore, technologies to preserve nanoparticles have been pursued.In a previous study, we developed a four-fluid nozzle spray dryer to produce microparticles containing nano-sized drug particles.6-11) This nozzle has two liquid and two gas passages that allow two compounds (e.g., a water-insoluble drug in organic solvent and a water-soluble carrier in aqueous solution) to be dissolved in separate solvents, thereby overcoming the problems of finding and using a common solvent. Although the detailed mechanism of the production of drug nanoparticles/water-soluble carrier microparticles by using the...

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“…In addition, drug loaded microspheres have the ability of targeting at site of action, leading to a decrease in the dose required and side effects 7 . The report by Duarte et al, (2007) showed that ophthalmic drug delivery systems of Acetazolamide using Eudragit RS 100 and RL 100 exhibited slower release than single drug 8 .…”

Section: Introductionmentioning

confidence: 99%

Chitosan Loaded Microspheres of Tropicamide as Controlled Release of Drug for Ocular Drug Delivery System

Saini¹,

Kumar²,

Choudhary³

et al. 2017

Int. Res. J. Pharm.

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Ocular drug delivery via conventional eye drop is a convenient route of administration but it has serious limitations due to rapid clearance of the formulation from the eye. This study aimed to prepare and evaluate the sustained/controlled release of tropicamide microspheres with chitosan to increase ocular residence time of drug and also improve the bioavailability. The tropicamide loaded chitosan microspheres were prepared by ionic gelation technique using different ratios of polymer i.e. chitosan and cross-linking polymer i.e. sodium TPP. Microspheres were optimized by employing (2 2 ) factorial design and evaluated for particle size, entrapment efficiency, surface morphology and drug release profile. The entrapment efficiency was found to be higher with increase in the chitosan concentration. The increasing concentration of chitosan also showed the sustained release effect on the drug release. The optimized formulation showed the smooth morphology and average particle size was found to be about 15µm.The in-vitro release profile of tropicamide loaded microspheres showed a sustained release pattern as compared to pure drug. The results revealed that microspheres would be the promising candidates for enhancing the residence time by mucoadhesion which leads to enhancement of bioavailability of the tropicamide drug.

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Preparation of acetazolamide composite microparticles by supercritical anti-solvent techniques

Cited by 52 publications

References 13 publications

Design and Pharmacodynamic Evaluation of Optimized Microporous Osmotic Tablets of Venlafaxine Hydrochloride

Design and Pharmacodynamic Evaluation of Optimized Microporous Osmotic Tablets of Venlafaxine Hydrochloride

Development of a Novel and Customizable Two-Solution Mixing Type Spray Nozzle for One-Step Preparation of Nanoparticle-Containing Microparticles

Chitosan Loaded Microspheres of Tropicamide as Controlled Release of Drug for Ocular Drug Delivery System

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