The Procter Gamble Company

Abbott Laboratories Corporation

Maria Wisniewska-Wrona

Alojzy Urbanowski

Antoni Niekraszewicz

Henryk Struszczyk

Henryk Struszcyk

Ewa Wesolowska

Danuta Ciechanska

Magdelena Kucharska

Magdalena Kucharska

Disclosed are methods of producing modified microcrystalline chitosan. Chitosan in aqueous solution is degraded enzymatically, hydrolytically or oxidatively. The chitosan solution is then alkalized with agitation using aqueous hydroxides and/or their salts to attain a pH not lower than 7.0. The precipitated modified microcrystalline chitosan is highly pure and may be concentrated and dried according to known methods. Methods according to the invention also include methods by which an aqueous solution of chitosan is first alkalized using hydroxides and/or their salts to a pH not lower than 7.0. Then the precipitated microcrystalline chitosan is subjected to enzymatic or oxidative degradation to achieve a desired average molecular weight and polydispersity. The product is highly pure and may be concentrated and dried according to known methods.

Methods of producing modified microcrystalline chitosan and uses therefor

Disclosed is a process for producing particles of the modified carbohydrate polymer chitosan. Such chitosan particles are &ldquo;activated&rdquo; as a consequence of the specific steps used in the process. The process involves precipitation of dissolved chitosan from an acid solution thereof by the step-wise addition of neutralizing agent to the solution. A partial neutralization is carried out under shear agitation to form a continuous gel phase having a pH within the range of 5.0 to 6.9. This partially neutralized chitosan gel phase is then further subjected to shear agitation for at least 10 seconds to homogenize the gel phase. The homogenized gel phase is then further neutralized under shear agitation to a pH of above 6.9 to form a gel-like suspension of discrete chitosan particles. Chitosan particles in this form are useful in a number of contexts including, in particular, in the area of plant care.

Process for preparing chitosan particles

Growing community of inventors

Lodz, Poland

Maria Wisniewska-Wrona