Stability, dosage form

Animal uses employ resin in various stabilized forms at levels of 200,000 400,000 500,000 and 1 x 10 units of per gram. Combination products containing A and D are also available, with 650,000 units of vitamin A and 325,000 units vitamin D per gram of product being the most common dosage form. 

Kinetics can also be applied to the optimization of process conditions, as in organic syntheses, analytical reactions, and chemical manufacturing. This last example constitutes an important aspect of chemical engineering. Yet another practical use of chemical kinetics is for the determination and control of the stability of commercial products such as pharmaceutical dosage forms, foods, paints, and metals. 

Stability Testing of New Drug Substances and Products Stability Testing Photostability Testing of New Drug Substances and Products Stability Testing for New Dosage Forms... 

SHELFLIFE.dat The content (% of nominal) of two active components in a dosage form was assayed at various times (0-60 months) during a pharmaceutical stability trial to determine the acceptable shelf-life of the formulation the point at which the lower 90% confidence limit of the finear regression model intersects the 90%-of-nominal line gives the answer. Use with SHELFLIFE or LINREG. 

Fractional Order. In the decomposition of pure solids, the kinetics of reactions can often be more complex than simple zero- or first-order processes. Carstensen [88] has reviewed the stability of solids and solid dosage forms as well as the equations that can be used in these cases. In addition to zero- and first-order kinetics, solid-state degradations are often described by fractional-order equations. 

A rational way to develop approaches that will increase the stability of fast-degrading drugs in pharmaceutical dosage forms is thorough study of the factors that can affect such stability. In this section, the factors that can affect decomposition rates are discussed it will be seen that under certain conditions of pH, solvent, presence of additives, and so on, the stability of a drug may be drastically affected. Equations that may allow prediction of these effects on reaction rates are discussed. 

As mentioned earlier in this chapter, penicillins are very unstable in aqueous solution by virtue of hydrolysis of the p-lactam ring. A successful method of stabilizing penicillins in liquid dosage forms is to prepare their insoluble salts and formulate them in suspensions. The reduced solubility of the drug in a suspension decreases the amount of drug available for hydrolysis. An example of improved stability of a... 

Current Good Manufacturing Practices [135] establish the requirements for maintaining a stability program and require that most pharmaceutical dosage forms have an established expiration date supported by test data [134]. There are few allowable exceptions. 

R. C. Schultz, Stability of Dosage Forms, FDA-Industry Interface Meeting, Washington, DC, Oct. 7, 1983 Stability Guidelines, Congressional Record, May 7, 1984. 

Topical preparations, like all other dosage forms, must be formulated, manufactured, and packaged in a manner that assures that they meet general standards of bioavailability, physical (physical system) stability, chemical (ingredient) stability, freedom from contamination, and elegance. Like all other pharmaceuticals, these factors must remain essentially invariant over the stated shelf life of the product and they must be reproducible from batch to batch. 

Concern for the physical and chemical integrity of topical systems is no different than for other dosage forms. However, there are some unique and germane dimensions to stability associated with semisolid systems. A short list of some of the factors to be evaluated for semisolids is given in Table 12. All factors must be acceptable initially (within prescribed specifications), and all must remain so over the stated lifetime for the product (the product s shelf life). 

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]. 

Colorants do not contribute to therapeutic activity, nor do they improve product bioavailability or stability. Indeed, they increase the cost and complication of the manufacturing process. Their main role is to facilitate identification and to enhance the esthetic appearance of the product. In common with all material to be ingested by humans, solid dosage forms are severely restricted in the coloring agents that are allowable. This situation is complicated by the lack in international agreement on an approved list of colorants suitable for ingestion. 

KS Murthy, I Ghebre-Sellassie. Current perspectives on the dissolution stability of solid oral dosage forms. J Pharm Sci 82 113-126, 1993. 

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