Pharmaceutical dosage forms suspensions

This chapter describes the basic principles involved in the development of disperse systems. Emphasis is laid on systems that are of particular pharmaceutical interest, namely, suspensions, emulsions, and colloids. Theoretical concepts, preparation techniques, and methods used to characterize and stabilize disperse systems are presented. The term particle is used in its broadest sense, including gases, liquids, solids, molecules, and aggregates. The reader may find it useful to read this chapter in conjuction with Chapters 8, 12, and 14, since they include some of the most important applications of disperse systems as pharmaceutical dosage forms [1]. 

An interface is defined as a boundary between two phases. The solid/liquid and the liquid/liquid interfaces are of primary interest in suspensions and emulsion, respectively. Other types of interfaces such as liquid/gas (foams) or solid/gas interfaces also play a major role in certain pharmaceutical dosage forms, e.g., aerosols. 

RA Nash. Pharmaceutical suspensions. In HA Lieberman, MM Rieger, GS Banker, eds. Pharmaceutical Dosage Forms Disperse Systems, Vol. 1. New York Marcel Dekker, 1988, pp 151-198. 

Sadana and Gaonkar described a simultaneous derivative spectroscopic method for the determination of diloxanide furoate and tinidazole in pharmaceutical dosage forms [26]. Drugs were powdered and dissolved in methanol, and the solution set aside for 30 minutes with frequent shaking. After filtration, the filtrate and washings were diluted with methanol. A suspension equivalent to 150 mg of diloxanide furoate was extracted with chloroform. The filtered extract was evaporated to dryness, and the... 

Sadana and Gaonkar have simultaneously determined diloxanide furoate and tinidazole in pharmaceutical dosage form by gas liquid chromatography [37]. Powdered tablets or suspension formulations were dissolved in chloroform, the solution filtered, and then diluted to 25 mL with chloroform. The solution also contained metronidazole as an internal standard. A 600 nL aliquot was analyzed on a stainless steel column (1 m X 3.2 mm) containing 3% of OV-17 on Chlorosorb W-UP (100-120 mesh). The GC system was operated at 200°C, using nitrogen as the carrier gas (45 mL/min). Flame ionization detection was used to observe the analytes. 

Floyd, A.G. Jain, S. Injectable emulsions and suspensions. 36. In Pharmaceutical Dosage Forms Dispersed Systems, 2nd... 

The adsorption of surfactants onto solid surfaces is important with respect to their detergent properties, their use as wetting agents in solid pharmaceutical dosage forms, and as stabilizers for suspension formulations. The mode of action of surfactants in each of these systems is discussed further below. 

A suspension is often chosen as pharmaceutical dosage form for drugs insoluble in water and aqueous fluids at the dosage required for administration and when attempts to solubilize the drug would compromise stability and safety. For oral administration, the taste of a bitter or unpleasant drug can often be masked by choosing an insoluble form of the active drug. 

Nash, R.A. Pharmaceutical suspensions. In Pharmaceutical Dosage Forms, Dispersed Systems Lieberman, H.L., Rieger, M.M., Banker, G.S., Eds. Marcel Dekker, Inc. New York, 1988 1, 151-198. 

Sciarra JJ. Aerosol suspensions and emulsions. In Lieberman H, Rieger M, Banker G, eds. Pharmaceutical Dosage Forms Disperse... 

Building A of ABC Pharmaceutical is designed to manufacture dry oral products. The conventional pharmaceutical dosage forms include tablets, capsules, and powders for suspension. 

Bhargava, H.N. Nicolai, D.W. Oza, B.J. Topical Suspensions Pharmaceutical Dosage Forms Disperse Systems. Marcel Dekker New York, 1996 Vol. 2, pp. 183-241. 

JB Boyett. CW Davis. Injectable emulsions and suspensions. In Liebermann H. A., Rieger M. M., Banker G. S. eds. Pharmaceutical dosage forms. Disperse systems, Vol 2. New York Marcel Dekker, 1989, pp, 397-413. 

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