• Journal of Pharmaceutical Investigation
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• 제38권3호
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• pp.177-182
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• 2008

The purposes of this study were to prepare dual-layered coated compact pellets containing three nutrients Glucose, Chromium picolinate, Vitamin C) for rumen bypass. The core compact pellets were prepared by an extrusionspheronization method and then double layered coated with pH independent EC (ethyl cellulose) and pH-dependent polymers ($Eudragit^{(R)}$ E100) using a fluid-bed spray coater. Depending on the coating levels of EC and $Eudragit^{(R)}$ E100, release profiles were variable in simulated rumen (pH 6.8) and abomasums (pH 2.0) fluid using USP apparatus I (basket method). When compact pellets were coated with EC (about 10% level in inner layer) and then $Eudragit^{(R)}$ E100 (20% level in outer layer) in a dual-layered manner, rumen-bypass delivery resisting rumen fluid followed by release in abomasums fluid could possible. The friability was also satisfactory based on chewing behavior of ruminants. The dual-layered coated compact pellets showed smooth surface and distinct inner/outer layers using scanning electron microscopy (SEM). The current rumen bypass delivery system can be also applicable to deliver other nutrients in ruminants.

• Journal of Pharmaceutical Investigation
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• 제37권2호
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• pp.101-106
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• 2007

Venlafaxine, 1-[2-(dimethylamino)-1-(4-methoxyphenyl)ethyl] cyclohexanol hydrochloride is a novel, nontricyclic antidepressant. venlafaxine is a unique antidepressant that differs structurally from other currently available. The aim ot the study was to formulate sustained-release venlafaxine granules and assess their formulation variables. It consists of two layers, venlafaxine drug layer and sustained release coating layer and manufactured by fluidized bed process. The sustained release of drug could be increased by double-control rising various components in venlafaxine drug layer and sustained-release layer. The drug-containing granules were coated with cellulose acetate, cetyl alcohol and Eudragit RS along with plastisizer such as dibuthyl sebacate as an nano-pore former The release oi venlafaxine depended on the type of Eudragit such as RS, and RL used in the formulation of controlled release layer. These results obtained clearly suggest that the sustained release oral delivery system for venlafaxine could be designed with satisfying drug release profile approved.

• Archives of Pharmacal Research
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• 제20권6호
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• pp.555-559
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• 1997

The three different batches of an oral sustained release melatonin (MT) delivery system were prepared by aqueous-based fluid-bed coating of the sugar spheres for the evaluation of in vitro release characteristics and plasma concentration profiles in human subjects. The MT contents in 20% coated sugar spheres of three batches (B1, B2 and B3) were $3.3{\pm}0.08$, $2.4{\pm}0.1$ and $2.5{\pm}0.13$ mg per gram of coated sugar spheres, respectively. The release profiles of three different batches had a very similar fashion. However, the release profiles of three different batches had a very similar fashion. However, the release half-lives $(T_{50%})$ of MT from B1, B2 and B3 was $3.70{\pm}0.2$, $5.2{\pm}0.2$ and $4.9{\pm}0.07h$, respectively. Plasma concentration profiles of sustained release 0.2mg melatonin-loaded sugar spheres containing 10% immediate release melatonin in gelatin capsules (B1 and B2) were then evaluated in human subjects. The in vivo plasma concentration profies of the two batches (B1 and B2) were very similar each other and located between the physiological endogenous ranges. The time to reach the peak concentration $(T_max)$ was more advanced in case of B1 when compared to B2. However, there was no statistically significant difference in the maximum concentration $(C_max)$ and the area under the curve (AUC) between B1 and B2. The AUC of melatonin-loaded sugar spheres containing 10% and 20% immediate release MT in human subjects had a good linearity between dose and AUC, regardless of the fraction of immediate release MT, indicating the first order elimination process of MT within these doses. The current oral sustained release MT delivery system may be utilized to treat circadian rhythm disorders if it is proven to be more clinically useful when compared to immediate release MT.