Sucrose esters with various hydrophilic–lipophilic properties: Novel controlled release agents for oral drug delivery matrix tablets prepared by direct compaction

Sucrose esters (SE) are esters of sucrose and fatty acids with various hydrophilic–lipophilic properties which have attracted interest from being used in pharmaceutical applications. This study aimed to gain insight into the use of SE as controlled release agents for direct compacted matrix tablets. The study focused on the effect of hydrophilic–lipophilic properties on tableting properties and drug release. Sucrose stearate with hydrophilic–lipophilic balance (HLB) values ranging from 0 to 16 was systematically tested. Tablet formulations contained SE, metoprolol tartrate as a highly soluble model drug and dibasic calcium phosphate dihydrate as a tablet formulation filler in the ratio 1:1:2. The compaction behaviour of matrix tablets was compared with the compacts of individual starting materials as reference. SE incorporation improved the plasticity, compressibility and lubricating property of powder mixtures. The hydrophilic–lipophilic properties of SE affected tableting properties, drug release rate and release mechanism. Increasing hydrophilicity corresponding to the increased monoesters in SE composition increased the relative porosity, elastic recovery and tensile strength of the tablets due to the increased hydrogen bonding between the monoesters. This also facilitated the swelling behaviour of SE, which sustained the drug release rate. A sustained release effect prevailed in tablets containing SE with HLB values of 3–16. The ability to improve the tableting properties as well as sustain the drug release rate of the highly soluble model drug via gelation of SE highlights SE as promising controlled release regulators for direct compacted matrix tablets comprising drugs with various solubilities according to the Biopharmaceutics Classification System.