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Tablets & Capsules October 2015 35 have since been incorporated into official compendia. This "super" effect was mainly associated with the powerful disintegration force that these new excipients generated at low concentrations (2 to 4 percent w/w) compared to traditional disin- tegrants. Market demand Most medicines today usually contain one of three of the main dis- integrant types: SSG, croscarmellose sodium (CCS), or crospovidone (XP) [1]. See Figure 1. Estimated global consumption of disintegrants exceeds 1 7,000 m etric t ons p er annum [2]. All three disintegrants have a similar m arket share, although China and India use more SSG compared to the more devel- oped markets. The world's three leading suppliers of SSG, all based in Europe, are DFE Pharma (Primojel, made i n t he N etherlands), J RS Pharma (Vivastar, m ade i n Germany), and Roquette (Glycolis, made in France). Each has a signifi- cant market share, with the remain- ing fragments distributed among sev- eral small t o m edium-size l ocal suppliers. It is well known that the brand- to-brand variability of superdisinte- grants influences performance, but the reason or reasons for that are not fully understood. But raw material sourcing, particle size, batch-to- batch consistency, degree of substi- tution, and cross-linking [3] may have a significant impact on a super- disintegrant's performance in a for- mulation. Indeed, no general rules apply to using specific superdisintegrants in particular formulation matrices. Rather, formulators can select any superdisintegrant b ased on t he nature of the API and the target dis- integration profile. Among the top- 200 marketed formulations, there isn't any particular correlation with the most commonly used matrices (microcrystalline cellulose (MCC) and lactose) and the choice of super- disintegrant. In fact, SSG, CCS, and XP are used at more or less similar frequencies in lactose- and/or MCC- based formulations (Figure 2) [4]. SSG is also used in formulations containing other filler-binders, such as mannitol and the dicalcium phos- phates. Chemistry and typical physical properties SSG is a sodium salt of a carboxy- methyl ether of starch or of a cross- This edition of the column describes the development of sodium starch glycolate and its use as a superdisintegrant in oral solid dosage forms. Starches are widely used in phar- maceutical dosage forms as a sus- pending agent, binder, disintegrant, and film-forming agent. A variety of types a nd g rades of functional starch-based excipients are available. This article focuses on the applica- tion of cross-linked starch, com- m onl y known as sodium car- boxym eth yl starch and sodium starch glycolate (SSG). Developed in the 1960s, SSG is a proven, well- established superdisintegrant com- monly used in today's drug formula- tions. Disintegrants are used in oral s ol i d dos age forms (OSDFs) to enhance the rate at which the drug pr odu ct's active pharmaceutical ingredient (API) becomes bioavail- able. Starches—both native and pre- gelatinized forms—are the tradi- tional tablet disintegrants, and to exert sufficient disintegration force, they must be used at high concentra- tions, typically 10 to 50 percent (w/w), which affects the tablet's mass and compression properties and makes formulating with them chal- lenging. In the early 1960s, researchers sought to overcome those challenges by reducing the disintegrant dose while maintaining the desired disin- tegration effect. The result was a new generation of disintegrants, the so-called "super" disintegrants, which Figure 1 Use of superdisintegrants in marketed formulations [1] 25% 34% 41% CCS SSG XP eye on Ranjita Shegokar and Cas Wiebinga DFE Pharma excipients