Ensuring the adequate bioavailability of active substances is one of the major challenges facing the pharmaceutical industry. A potential solution to improve bioavailability is the incorporation of active ingredients into lipid delivery systems, including self-
microemulsifying delivery systems. After oral administration, these systems undergo digestive processes that are difficult to reproduce with conventional release tests. Thus, these systems are biopharmaceutically evaluated using in vitro lipolysis models that mimic physiological conditions of lipid digestion. The aim of this thesis was to perform a literature review of published studies and to analyse the parameters that have the most influence on in vitro lipolysis. Our analysis will be used to set up an optimised hypothetical model for the pH stat method of in vitro lipolysis. We systematically searched the Pubmed database for research articles describing the in vitro lipolysis method that mimics the process of lipolysis in the beginning of small intestine. We found a final 31 research articles that met the entry criteria. We detailly analysed the concentrations of surfactants, sodium chloride, calcium ions, the type and concentration of the lipolysis buffer and the activity and origin of the enzymes used. The data obtained were graphically displayed and evaluated. For all parameters analysed, we also separated the data according to fasting or fed state. From the data we calculated the mean concentrations, standard deviations and concentration ranges for bile salts, phospholipid, buffers and sodium chloride. For the pancreatic lipase data, we calculated the mean activities, standard deviations of activity and determined the lipase activity ranges. The following conclusions were reached: tris-maleate buffer was the most commonly used buffer, and all studies were conducted in the pH range 6,8 -8,0. The average fasting buffer concentration was 16 mM and the fed buffer concentration was 40 mM. The most commonly used bile acid salt was sodium taurodeoxycholate at a concentration of 4 mM fasting and 19 mM fed. Phosphatidylcholine has been the most commonly used phospholipid. In fasting studies, it has been used at a concentration of 1 mM. The average fasting calcium ion concentration was 3,21 mM and the fed concentration was 5 mM. The most frequently mentioned source of lipase was porcine pancreatin. The average fasting and fed porcine pancreatin activity was 660 USP/mL.
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