Clays, excipients

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. 

Like APIs, pharmaceutical excipients are made by chemical synthesis, fermentation, recovery from natural materials, and so on. Often purification procedures may not be employed in the manufacture of such pharmaceutical excipients as clays, celluloses, starches, and natural gums. In addition, the physical and chemical change of certain excipients during processing is not uncommon. Unlike APIs, many excipients have complicated chemical and physical structures that do not yield easily to modern analytical and chromatographic methods. 

ESCS (expanded shale, clay, and slate) 310 evactherm 306 excipient 100, 126... 

Carretero MI, Pozo M (2009) Clay and non-clay mincmds in the pharmaceutical industry Part I. Excipients and medical applications. Appl Clay Sci 46 73-80... 

The use of clay minerals in pharmaeeutieal formulations was described by many authors (Del Pozo 1978, 1979 Gala n et al., 1985 Bech, 1987 Cornejo, Kaolinite, talc, palygorskite and smectites are used for therapeutic purposes in pharmaceutical formulations as active principles or excipients. The possible use of sepiolite as active principle or excipient in pharmaceutical formulations was also investigated and there are commercial medicines that include sepiolite in its composition (as active principle and excipient). The fundamental properties for which clay minerals are used in pharmaceutical formulations are high specific area and having sorptive capacity and favourable rheological characteristics. 

Nanoclays can be categorized into cationic and anionic types. Cationic nanoclays are based on smectite clays. An example is montmorillonite (MMT), a hydrated Al, Mg silicate that may contain cations such as Na+ and Ca++ between the anionic layers. In contrast, anionic clays contain cationic layers and anions such as Cr and in the interlayer space. Typical examples include layered double hydroxides (LDH) and hydrotalcite (HT), a mostly synthetic hydrated magnesium and aluminum carbonate salt. Whereas MMT is commonly used as a nanofiller to improve thermal, mechanical, and barrier properties, LDHs have many attractive properties that lead to application as surfactant adsorbents, biohybrid materials, antacid food formulations, acid neutralizers, and active pharmaceutical ingredients excipients [37, 13, 28, 14, 35]. 

Oral Solid Dosage Forms (OSDF) and Pharma Excipients Market for Polymers (MCC, HPMC, CMC, Ethyl Cellulose, Povidone and Others), Alcohols (Glycerin, Sorbitol, Mannitol, Propylene Glycol), Minerals (Clay, Silicon Dioxide, Titanium Dioxide) and Sugars (Lactose, Sucrose) - Global Industry Analysis, Size, Share, Trends, Analysis, Growth and Forecast, 2012 - 2018,2013. 

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