Excipient materials

The second example is the SE-HPLC analysis of recombinant hGH. In this example, SE-HPLC is used for both a purity and a protein concentration method for bulk and formulated finished products. This method selectively separates both low molecular weight excipient materials and high molecular weight dimer and aggregate forms of hGH from monomeric hGH, as shown... 

It may sometimes by necessary to supplement the properties of the drug so that it compresses more easily, and these needs have been realized by several manufacturers of excipients. Materials described as compression aids are now commercially available. Ideally, such adjuvants should develop mechanical strength while improving, or at least not adversely affecting, release characteristics. Among the most successful at meeting both these needs have been the microcrystalline celluloses (partially acid-hydrolyzed forms of cellulose). A number of grades are available based upon particle size and distribution. 

Absorbents are another class of excipient material used in feed additive premixes. They are used when the drug substance is a liquid or is readily soluble in water, oil, or some other solvent. The liquid is sprayed onto the absorbent in a mixer as the mixer is running. Examples of absorbents are vermiculite, Fullers earth, corn cob fractions, and clay. 

The moisture uptake models we have discussed have been concerned with pure components. The deliquescing material could be a drug substance or an excipient material. In pharmaceuticals, however, mixtures of materials are also important. One possible situation involves mixing nondeliquescing and deliquescing materials that are formed into a porous tablet or powder blend. The obvious question is, Do the models for pure components apply to porous heterogeneous materials For pure components we have assumed that the mass and heat limiting transport... 

Overall, a wide range of testing considerations are needed for new excipient materials, although the actual package of study types still remains a case-by-case approach. 

This chapter will deal with the objective of manufacturing excipient ingredients to appropriate good manufacturing practices (GMP) requirements, as stipulated by the United States Pharmacopeia (USP) (1) and the International Pharmaceutical Excipients Council excipient GMP guide (2). It is beyond the scope to address the many quality techniques for minimizing variation in excipient quality. However this chapter will address the issues concerning assurance that all excipient material within each batch meets compendial or manufacturer s specification. 

USP < 1078 > provides the following guidelines for the excipient manufacturer and the purchaser to use in establishing standards for excipient materials provided. 

R. A. Kenley, S. Chandry, and G. C. Visor, An automated columnswitching HPLC method for analyzing active and excipient materials in both cream and ointment formulations, Drug Dev. Ind. Pharm., 4 1781 (1985). 

Faribrother, J.E. Grant, D.J.W. Crystal engineering studies with an excipient material (adipic acid). J. Pharm. Pharmacol. 1979, 31, SuppL, 27 pp. 

A number of starch modifications are used in pharmaceutical applications. Pregelatinized or compressible starch has been chemically or mechanically processed to rupture all or part of the granules in water. It is then dried to yield an excipient material suitable for direct-compression formulations. Sterilizable maize starch contains magnesium oxide (not greater than 2.2%) and has been chemically or physically treated to prevent gelatinization on exposure to moisture or steam sterilization. Soluble starch results when potato or maize starch has been chemically treated to destroy the gelatinizing ability of starch. 

Brittain, H.G. Functionality testing of excipient materials. Pharm. Technol. 1993, 9 (9), 72-73. 

The series mission was expanded some time ago to include profiles of excipient materials, reflecting that these materials require the full degree of scrutiny historically associated with drug compounds. These highly detailed compilations of excipient properties and analytical methods have been well received by workers in the field, and such profiles will continue to be sought. In the present volume, the series mission is further expanded to include a profile of a natural product which has been used as a precursor material in the synthesis of new drug candidates. If this information proves to be of interest to the pharmaceutical community, additional chapters of this type will be developed. 

Be free from interference from the excipient materials... 

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