Particulate formulations

Pinocytosis. This process by which particles are absorbed can be an important factor in the ingestion of particulate formulations of chemicals (e.g., dust formulations, suspensions of wettable powders, etc.) however, it must not be confused with absorption by one of the above processes, where the agent has been released from particles. 

The following types of mucoadhesive preparations have been evaluated for ocular drug delivery hydrogels, viscous liquids, solids (inserts), and particulate formulations [57]. Hui and Robinson [58] introduced hydrogels consisting of cross-linked polyacrylic acid for ocular delivery of progesterone in rabbits. These preparations increased progesterone concentrations in the aqueous humor four times over aqueous suspensions. 

The kinetics of absorption of the drug following administration of the formulation of thiotepa in gelatin particles to rabbits suggested that not only was the blood level elevated compared to a control but the area under the curve (AUC) was essentially more than doubled. Since this represents the amount of drug absorbed the authors suggested that administration of a simple gelatin particulate formulation... 

Douroumis, D., and Fahr, A. (2006), Nano- and micro-particulate formulations of poorly water-soluble drugs by using a novel optimized technique, Eur. J. Pharm. Biopharm., 63,173-175. 

Huyghebaen N. Vermeire A, Neirynck S, et al. Evaluation of extrusion/spheronization, layering and compaction for the preparation of an oral, multi-particulate formulation of viable, hIL-IO producing Lac/ococus /ac/ts. Eur J Pharm Biopharm 2005 59 9-15. 

Copland MJ, Rades T, Davies NM, Baird MA (2005) Lipid based particulate formulations for the delivery of antigen. Immimol CeU Biol 83 97-105... 

Sarup L, Tservistas M, Sloan R, Hoare M, Humphreys GO. Investigation of supercritical fluid technology to produce dry particulate formulations of antibody fragments. Trans Inst Chem Eng 2000 78 101-104. 

Also Tablet. A compressed agglomerate made of particulate solids, specifically, in pharmacy, a small compact of a medicated particulate formulation usually in the shape of a disc or a flat polyhedral body. (See also briquette.) The process of forming tablettes. 

Drug solutions for pulmonary applications combine several benefits over particulate formulations, but there are severe drawbacks as well. Beneficial is the ease of access to Kquid formulations, which are typically available for parenteral administration in the first place, thereby allowing for an immediate start of development activities. One further benefit is the rather low stress, which is exposed on the proteins during manufacture. One drawback versus dry, particle-based formulation, however, is the rather low drug load of the water-based formulations ranging predominantly from 1 to 2%, thereby requiring the aerosolization of large quantities of formulation. 

Figure 1.8. The clearence of 99m-Tc-sodium pertechnetate and 99m-Tc-diethylenetriaminepentaacetic acid, respectively, from the nasal cavity following administration of a chitosan particulate formulation (squares) and the control without such carrier (circles) (data from ref. (133))...

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