Drug release mechanism

R. E. O Connor, The Drug Release Mechanism and Optimization of a Microcrystalline Cellulose Pellet System, Ph.D. dissertation, Philadelphia College of Pharmacy Science, 1987. 

Methods for synthesizing highly porous microspheres were investigated, and surface area measurements were used to confirm the porous nature of the samples [19]. A high surface area was measured and was compared with the calculated surface area value. The measured value was 35 times that of a nonporous particle, indicating the extensive porosity of the spheres. The surface area was also used to explain the drug release mechanisms in the pores of these systems. 

P a Membrane surface area Drug release mechanisms... 

Regardless of the drug release mechanism, utilizing polymers as a drug delivery vehicle enables controlled and sustained release of the drug. Moreover, for a DES, this has the added benefit of localized delivery to a specific target, that is, the stented artery area. 

For modified-release tablets, when the drug product is in the same dosage form but in a different strength, is proportionally similar in its active and inactive ingredients, and has the same drug release mechanism, an in vivo BE determination of one or more lower strengths can be waived based on dissolution profile comparisons, with an in vivo... 

Another parameter determining the drug release mechanism from glassy hydrogels, the swelling interface number, Sw has been introduced as ... 

Papadopoulou, V., Kosmidis, K., Vlachou, M., and Macheras, P., On the use of the Weibull function for the discernment of drug release mechanisms, International Journal of Pharmaceutics, In press. 

Lin, Y-K., and Ho, H-O. (2003), Investigations on the drug releasing mechanism from an asymmetric-membrane-coated capsule with an in situ formed delivery orifice, J. Controlled Release, 89, 57-69. 

Munday DL, Cox PJ. Compressed xantham and karaya gum matrices hydration, erosion and drug release mechanisms. Int ] Pharm 2000 203 179-192. 

Technologies to increase gastrointestinal retention time Technologies to improve drug release mechanisms of oral preparations Adjuvants to enhance absorption Methods of increasing bioavailability of drugs Penetration enhancement Improved dissolution rate... 

Improving Drug Release Mechanisms of Oral Preparations... 

DP method utilizes ink-jet printing technology to create a solid object by printing a binder into selected areas of sequentially deposited layers of powder. The active agent can be embedded into the device either as dispersion along the polymeric matrix or as discrete units in the matrix structure. The drug release mechanism can be tailored for a variety of requirements such as controlled release by a proper selection of polymer material and binder material. 

Time-controlled drug delivery systems can be classified according to different principles, for example, with respect to the route of administration, field of application, and/or underlying drug-release mechanisms. In this chapter, the various types of devices that have been described so far in literature have been classified based on the major... 

Klose D, Siepmann F, Elkharraz K, et al. How porosity and size affect the drug release mechanisms from PLGA-based microparticles. Int J Pharm 2006 314 198-206. 

As with ordinary ATR spectroscopy, ATR-FT-IR imaging results can be analyzed quantitatively, some recent examples including the study of tablet dissolution in water. In this case, the concentration profiles of hydroxylpropylmethylcellulose (HPMC) and niacinamide, at different stages of the dissolution process, were utilized to provide an understanding of the drug release mechanism [54]. Using this technique, it could be shown that the concentration profiles of different components could be obtained with the partial least squares (PLS) method. Here, with... 

Investigation of drug release mechanisms, especially for ER formulations... 

The three most common dominant, though not exclusive, microparticle drug release mechanisms are dissolution, diffusion, and erosion. Introduction of CyDs into polymeric network can modify mechanisms by which a drug is released [38], inducing immediate [19, 28], delayed, or prolonged liberation [23, 24]. 

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