English to Russian Medical Medical: Pharmaceuticals

Подскажите, пожалуйста, как перевести указанное предложение в данном контексте:
3.3.3 Detailed Process Description
II. Preparation of Hydroxyethylcellulose Concentrate
In a suitable stainless steel vessel set with variable speed agitation, add :
Water for Injection EP/USP min 77 °C 128 kg Add to disperse and dissolve with high speed agitation at 850-1400 rpm for a minimum of 15 minutes:
Hydroxyethylcellulose EP/NF 1.90 кг
Amount is corrected according to water content.
Heat the HEC concentrate to 98 - 102°C and hold at this temperature for 30 minutes to dissolve chemical.
Sample the solution for bioburden determination.

не совсем понятна структура предложения,его начало -добавить до растворения???.... с скоростью вращения 850 оборотов в минуту