Tag Archives: bioavailability

Ex vivo permeability study and in vitro solubility characterization of oral Canagliflozin self-nanomicellizing solid dispersion using Soluplus® as a nanocarrier

DOI: 10.2478/amma-2024-0011

Background and objective: Self-nanomicellizing solid dispersion SNMSD is a new formulation that combines solid dispersion and nanomicelle strategies; the strategy involves utilizing a suitable carrier that self-assembles into nanomicelles when interacting with gastrointestinal fluids. Canagliflozin, a sodium-glucose cotransporter-2 inhibitor for treating type 2 diabetes, has been linked to poor absorption due to its insolubility in aqueous media. The study aimed to create self-nanomicellizing solid dispersion systems for canagliflozin to overcome its pharmaceutical limitations and improve oral bioavailability.
Materials and Methods: Soluplus® was chosen as a nanocarrier to improve canagliflozin solubility after screening several polymers using a phase solubility study. The solvent evaporation method was selected for preparing the solid dispersion. The optimal formula was characterized through ex vivo permeability and in vitro studies.
Results: The CFZ-SNMSD formula, with a particle size PS of 60.77±1.00 nm and polydispersity index PDI of 0.06±0.02, has a stable distribution upon dilution to 20-fold with water. The apparent solubility of canagliflozin in the optimized CFZ-SNMSD formula was enhanced by 904.40±4 folds due to amorphization and nanomicellization, as demonstrated by transmission electron microscopy. CFZ-SNMSD formula showed a significant enhancement in dissolution rate compared to the physical mixture and pure drugs. The dissolution efficiency parameter confirms these findings (DE30, CFZ-SNMSD = 77.20% compared to DE30, pure drug = 18.28%). Studies show that canagliflozin’s permeability increases exponentially over time due to Soluplus® dispersibility, solubilization, and glycoprotein inhibitory effect, enhancing bioavailability and overcoming GIT membrane barriers.
Conclusions: The study indicates that canagliflozin self-nanomicellizing solid dispersion systems are promising methods for improving the oral bioavailability of canagliflozin medication.

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Physical and Chemical Study of Simvastatin Inclusion Complexes

Background: Simvastatin is an inhibitor of hydroxy-methyl-glutaryl-coenzyme A reductase, used in the treatment of hypercholesterolemia.
Aim: To enhance his bioavailability through inclusion complexation, as host molecule hydroxypropyl-b-cyclodextrin had been used. The objective of this study is to present our results of the study of some simvastatin and hydroxypropil-b-cyclodextrin (HPbCD) inclusion complexes. We analyzed the products by phase solubility study, dissolution test and Fourier-transformed Infrared Spectroscopy (FT-IR).
Methods: Complexes were prepared by kneading molecular ratios of 1:1 and 1:2 and compared also with physical mixtures. Solubility studies were performed in the presence of various HPbCD concentrations and the stability constant was calculated. The inclusion complexation was evaluated by dissolution and Fourier transformed infrared spectroscopy.
Results: When compared with the pure drug, the dissolution of simvastatin is improved in the presence of b-cyclodextrin derivates, depending on the complex preparation method.
Conclusions: The solubility of simvastatin increases as a function of HPbCD concentration. FT-IR study suggests the presence of intermolecular hydrogen bonds between simvastatin and HPbCD in inclusion complex.

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Physical and Chemical Study of Lovastatin Inclusion Complexes. Bioavailability Improvement

Background: Lovastatin is an inhibitor of hydroxy-methyl-glutaryl-coenzyme A reductase, used in the treatment of hypercholesterolemia. To enhance its bioavailability through inclusion complexation, as host molecule hydroxypropyl-b-cyclodextrin had been used.
Methods: Complexes were prepared by kneading in molecular ratio 1:1 and compared also with a physical mixture in molecular ratio 1:1. The complex was studied by performing dissolution tests and differential scanning calorimetry.
Results: Mixing the drug with the host molecule the soluble amounts were increased to 1.55 mg in artificial gastric juice and 2.99 mg in artificial intestinal juice. Kneading also improved the solubility of lovastatin to 1.94 mg in artificial gastric juice and 2.78 mg in artificial intestinal juice. In the thermograms a sharp endotherm peak was observed at the same position of lovastatin.
Conclusions: Dissolution studies showed an improvement of the drug release both in artificial gastric and intestinal juice. The sharp endotherm peak on the DSC curves indicates the untrapped lovastatin.

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