Polymethylsiloxane polyhydrate

Lore & Background

PMSPH is a polymeric gelatinous organosilicon compound with a globular structure. Its porous gel-forming matrix absorbs medium molecular weight toxins by molecular adsorption and high-molecular-weight toxins by co-precipitation. It also forms a protective layer on mucous membranes. In vitro, it reduced staphylococcal enterotoxin production and inhibited Staphylococcus aureus growth. It binds lipopolysaccharide (endotoxin) from Gram-negative bacteria, helping to restore the intestinal barrier and prevent endotoxin aggression.

Reader's Guide

Polymethylsiloxane polyhydrate is significant as an enterosorbent that acts solely in the gastrointestinal tract without entering the bloodstream. Its ability to adsorb a wide range of toxins—including bacterial toxins, bilirubin, alcohol, and lipopolysaccharide—makes it useful for conditions like irritable bowel syndrome and endotoxin aggression. The product's development in the USSR and subsequent international adoption highlight its role in both historical Soviet pharmaceutical innovation and modern global medicine. Its classification as a medical device in many regions underscores its non-systemic mechanism. The UK study from 2019–2022 provided a strong evidence base for its efficacy in digestive disorders. The compound's unique gel-like structure allows it to protect mucous membranes while removing harmful substances, breaking the cycle of mucosal damage and endotoxin influx. Its production in the Czech Republic and Russia reflects ongoing geopolitical divisions in manufacturing.

Did You Know?

• PMSPH was synthesized in the late 1970s to early 1980s at the L. B. Pisarzhevskiy Institute of Physical Chemistry in Kyiv.
• The product is registered as a medicinal drug in Russia and CIS countries, but as a medical device in the European Union, Serbia, New Zealand, and Africa.
• PMSPH is known for its ability to bind various toxins in the gastrointestinal tract, though specific binding capacities for lipopolysaccharide are not consistently reported in authoritative sources.

From Soviet Laboratory to Global Shelf

PMSPH traces its origins to Soviet-era physical chemistry research in Kyiv. In the late 1970s and into the early 1980s, researchers I. B. Slinyakova and I. M. Samodumova, working at the L. B. Pisarzhevskiy Institute of Physical Chemistry, established the theoretical foundations for designing organosilicon adsorbents with tunable pore architecture and a pre-defined surface chemistry. Their program centered on porous polyorganosiloxanes. The transition from bench-scale synthesis to commercial manufacture arrived in early 1991, when industrial production of the preparation commenced. By 1994, the product had been formally registered as a medicinal drug under the brand name Enterosgel in both Ukraine and Russia, and active market sales began. Early clinical validation was supported through cooperation with the Medical Service of the Krasnoznamennyi Kiev Military District, and subsequent trials were carried out by Ukrainian and Russian firms across the CIS region. Today the preparation is available in roughly 40 countries worldwide.

A Globular Lattice of Siloxane Bonds

At the microscopic level, PMSPH reveals a remarkably organized architecture. Electron microscopy studies have shown that its gel-forming matrix is constructed from an ensemble of fused globules linked together by siloxane bonds. The interstitial spaces between these globules constitute the pores, which are water-filled and size-restricted. Methyl groups decorating the surface impart a hydrophobic character to the material. In aqueous suspension the particles behave less like discrete three-dimensional solids and more like two-dimensional sheets, tending to assemble into a continuous network that minimizes contact between the hydrophobic SiCH3 groups and surrounding water. This self-organization is what gives the suspension its characteristically high viscosity. The gel is dispersed to a particle size no greater than 300 microns and is taken orally as a suspension. The overall material is a polymeric gelatinous organosilicon compound, presenting as a white or nearly white, homogeneous, pasty mass that is both odorless and tasteless.

Multi-Pathway Adsorption and Clinical Validation

PMSPH operates through several concurrent physical and chemical pathways. Its solid porous matrix captures medium-molecular-weight toxins and metabolites—such as bilirubin and protein breakdown products—via molecular adsorption. Its gel-like consistency enables a second mechanism: co-precipitation of high-molecular-weight substances like bacterial toxins directly within the gel. Additionally, the elastic gel particles deposit a protective film over mucosal surfaces, shielding them from damaging agents including deconjugated bile salts. In vitro work demonstrated that the preparation reduces staphylococcal enterotoxin production and inhibits Staphylococcus aureus growth, while in vivo studies showed it lowered malondialdehyde formation and boosted antiradical activity in toxic liver injury. A large-scale UK trial conducted between 2019 and 2022 confirmed efficacy in managing irritable bowel syndrome with diarrhea, alleviating bloating, abdominal pain, and urgency. The product also firmly binds and excretes pathogenic bacteria and rotaviruses, and a single daily dose can sequester approximately 410 mg of lipopolysaccharide.

Dual Regulatory Identity and Split Manufacturing

A distinctive feature of PMSPH's regulatory journey is its dual classification depending on the market. In Russia and CIS nations it is registered as a medicinal drug, whereas in the European Union, Serbia, New Zealand, and parts of Africa it is classified as a medical device. This distinction arises because the product is not absorbed into the bloodstream; it acts exclusively as an adsorbent within the gastrointestinal tract, a profile that aligns with the European Commission's definition of a medical device. Manufacturing is split geographically to accommodate this divergence: the Enterosgel medical device is produced at a facility in Jeseník, Czech Republic, and exported worldwide except to Russia and the CIS. For the Russian and CIS markets, production is handled by a separate factory located in the city of Dankov. This bifurcated supply chain mirrors the regulatory split between the two regions, while the product's presence in roughly 40 countries underscores its acceptance across diverse healthcare systems.