OBJECTIVE: Potential of a polysaccharide (rhamnogalacturonan)-based hydrogel from Linseeds (Linum usitatissimum L.) was investigated as an intelligent drug delivery material.
MATERIALS AND METHODS: Different concentrations of Linseed hydrogel (LSH) were used to prepare caffeine and diacerein tablets and further investigated for pH and salt solution-responsive swelling, pH-dependent drug release, and release kinetics. Morphology of tablets was observed using SEM.
RESULTS: LSH tablets exhibited dynamic swelling-deswelling behavior with tendency to swell at pH 7.4 and in deionized water while deswell at pH 1.2, in normal saline and ethanol. Consequently, pH controlled release of the drugs was observed from tablets with lower release (<10%) at pH 1.2 and higher release at pH 6.8 and 7.4. SEM showed elongated channels in swollen then freeze-dried tablets.
DISCUSSION: The drug release was greatly influenced by the amount of LSH in the tablets. Drug release from LSH tablets was governed by the non-Fickian diffusion.
CONCLUSIONS: These finding indicates that LSH holds potential to be developed as sustained release material for tablet.
MATERIALS AND METHODS: In a prospective study with purposive sampling, amoxicillin/clavulanate tablet formulations for canine use were collected in four countries (wholesalers or veterinary practice) and shipped to a central bioanalytical laboratory. Twenty-four samples were collected from the UK (nine), Malaysia (nine), Serbia (four) and Thailand (two), yielding 18 different formulations (10 veterinary). Packaging inspection, tablet disintegration and content assay were conducted (validated high-performance liquid chromatography with ultra-violet detection); content was acceptable when within the 90% to 120% pre-specified range (US Pharmacopeia).
RESULTS: Secondary packaging was present for 13 of 24 samples and primary packaging integrity was verified for all but one sample. Amoxicillin trihydrate/potassium clavulanate label ratio was 4:1, except for three formulations (2:1). Tablet dose strength ranged from 250 to 625 mg. All formulations contained both analytes. For amoxicillin, two of 24 samples were out of specification with 72.8% (Malaysia) and 82.3% (Thailand) of labelled content. For clavulanate, four of 24 samples were out of specification with 46.9% (Serbia), 79.0% (UK), 84.3% (Serbia) and 86.5% (Thailand) of labelled content. One formulation (Thailand) failed for both analytes.
CLINICAL SIGNIFICANCE: Antimicrobial formulations of substandard quality have negative consequences for efficacy in patients and potentially promote antimicrobial resistance. There was evidence of substandard formulations in all countries, not only for amoxicillin but especially for clavulanate; this could compromise equitable access to acceptable quality essential veterinary medicines worldwide.