Improved dissolution

It should therefore not be surprising that for relatively small-scale operations involving solids handling within the fine and intermediate chemicals industry, batch operation is preferred. Similarly, continuous processes that involve precipitation or crystallization, a common unit operation in fine chemicals, are rare. Small-scale examples are known, for instance, a continuous crystallization process was used by Bristol-Myres Squibb in order to improve dissolution rates and bioavailability of the product [12]. The above does indicate that not all process or parts thereof are suited for conversion from B2C, given the current technology. 

Barakat, N. S. (2006), Etodolac-liquid-filled dispersion into hard gelatin capsules An approach to improve dissolution and stability of etodolac formulation, Drug Dev. Ind. Pharm., 32, 865-876. 

Sertsou G, Butler J, Hempenstall J, Rades T. Solvent change co-precipitation with hydro-xypropylmethylcellulose phthalate to improve dissolution characteristics of a poorly water-soluble drug. J Pharm Pharmacol 2002 54 1041-1047. 

Crystal defects and imperfections inLuence the crystal lattice energy. These defects, including dislocations, give rise to increased surface energy and may be a major factor in improving dissolution performance of poorly water-soluble, crystalline substances. 

Serajuddin, A. T. M., P. C. Sheen PC, and M. A. Augustine. 1990. Improved dissolution of a poorly water-soluble drug from solid dispersions in polyethylene glycolj-polysorbate 80 mixtUfterm... 

Cavallari, C., Abertini, B., Gonzalez-Rodriguez, M., and Rodriguez, L., Improved dissolution behavior of steam-granulated piroxicam, European Journal of Pharmaceutics and Biopharmaceutics, Vol. 54, No. 1, 2002, pp. 65-73. 

Figure 13.23a shows the first mechanism, which is mainly chemical in nature. The silica removal rate is accelerated by the ceria-silica interactions, which results in the improved dissolution of the silica substrate during polishing. Figure 13.23b shows the second mechanism, which is based on physicochemical particle-surface interactions in which the ceria-silica bonding does not result in direct modification of the silica substrate but enhances the... 

Sparks, R. Jacobs, I. Mason, N. Method of Producing Porous Tablets with Improved Dissolution Properties. US Patent 6,544,552, April 8, 2002. 

Preechagoon, D. Udomprateep, A. Manwiwattanagul, G. Improved dissolution rate of poorly soluble drug by incorporation of buffers. Drug Development and Industrial Pharmacy 2000, 26, 891-894. 

The stability, both chemical and physical, of a drug may be enhanced or retarded by salt formation. For example, solid dosage forms of diclofenac contain salt forms rather than the less stable free acid. Although salt formation may result in improved dissolution rate and bioavailability of a poorly water-soluble compound, the preparation of stable salt forms for some drugs may not be feasible and the free acid or base forms may be preferred. For example, the base form of a-pentyl-3-(2-quinolinylmethoxy)benzenemethanol was selected for dosage form design because of the physical instability of its hydrochloride salt. ... 

Food increases the systemic availability of some cephalosporin prodrug esters, possibly by improving dissolution or blocking premature hydrolysis (361,362). 

Hypromellose phthalate may be used alone or in combination with other soluble or insoluble binders in the preparation of granules with sustained drug-release properties the release rate is pH-dependent. Since hypromellose phthalate is tasteless and insoluble in saliva, it can also be used as a coating to mask the unpleasant taste of some tablet formulations. Hypromellose phthalate has also been co-precipitated with a poorly soluble drug to improve dissolution characteristics. 

The thermodynamically favored form of a final product is usually the most desirable crystalline form, and screening studies should define the stability of the polymorphs. A less stable form may be preferred if it displays markedly improved dissolution and bioavailability. In this case it would be necessary to ensure that the less stable form can be reliably prepared on scale before committing to preparing this polymorph exclusively. 

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... 

Huang, S., Liu, J.-H., Xie, X.-Q., 1998b. Improved dissolution and maturation unit and its effect on polymer solubility. In Gang, Q.-L., et al. (Eds.), Chemical Hooding Symposium-Research Results during the Eighth Five-Year Period (1991-1995), vol. I. Petroleum Industry Press, pp. 409-413. 

Should the substance form be changed to improve dissolution (e.g., salt, polymorph, particle size) ... 

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