Formulation of a Gastroretentive In Situ Oral Gel Containing Metformin HCl Based on DoE

Development of a multi-component gastroretentive expandable drug delivery system (GREDDS) for personalized administration of metformin

OBJECTIVES

Efficacy and compliance of type II diabetes treatment would greatly benefit from dosage forms providing controlled release of metformin in the upper gastrointestinal tract. In this respect, the feasibility of a new system ensuring stomach-retention and personalized release of this drug at its absorption window for multiple days was investigated.

METHODS

The system proposed comprised of a drug-containing core and a viscoelastic umbrella-like skeleton, which were manufactured by melt-casting and 3D printing. Prototypes, alone or upon assembly and insertion into commercially-available capsules, were characterized for key parameters: thermo-mechanical properties, accelerated stability, degradation, drug release, deployment performance, and resistance to simulated gastric contractions.

RESULTS

Each part of the system was successfully manufactured using purposely-selected materials and the performance of final prototypes matched the desired one. This included: i) easy folding of the skeleton against the core in the collapsed administered shape, ii) rapid recovery of the cumbersome configuration at the target site, even upon storage, and iii) prolonged release of metformin.

CONCLUSIONS

Composition, geometry, and performance of the system developed in this work were deemed acceptable for stomach-retention and prolonged as well as customizable release of metformin in its absorption window, laying promising bases for further development steps.

Metformin HCl-loaded transethosomal gel; development, characterization, and antidiabetic potential evaluation in the diabetes-induced rat model

Herein we designed, optimized, and characterized the Metformin Hydrochloride Transethosomes (MTF-TES) and incorporate them into Chitosan gel to develop Metformin Hydrochloride loaded Transethosomal gel (MTF-TES gel) that provides a sustained release, improved transdermal flux and improved antidiabetic response of MTF. Design Expert® software (Ver. 12, Stat-Ease, USA) was applied for the statistical optimization of MTF-TES. The formulation with Mean Particle Size Distribution (MPSD) of 165.4 ± 2.3 nm, Zeta Potential (ZP) of -21.2 ± 1.9 mV, Polydispersity Index (PDI) of 0.169 ± 0.033, and MTF percent Entrapment Efficiency (%EE) of 89.76 ± 4.12 was considered to be optimized. To check the chemical incompatibility among the MTF and other formulation components, Fourier Transform Infrared (FTIR) spectroscopy was performed and demonstrated with no chemical interaction. Surface morphology, uniformity, and segregation were evaluated through Transmission Electron Microscopy (TEM). It was revealed that the nanoparticles were spherical and round in form with intact borders. The fabricated MTF-TES has shown sustained release followed by a more pronounced effect in MTF-TES gel as compared to the plain MTF solution (MTFS) at a pH of 7.4. The MTF-TES has shown enhanced permeation followed by MTF-TES gel as compared to the MTFS at a pH of 7.4. In vivo antidiabetic assay was performed and results have shown improved antidiabetic potential of the MTF-TES gel, in contrast to MTF-gel. Conclusively, MTF-TES is a promising anti-diabetic candidate for transdermal drug delivery that can provide sustained MTF release and enhanced antidiabetic effect.

The development of an in-situ biopolymer-based floating gel for the oral delivery of metformin hydrochloride

Diabetes remains a global public health threat because of its increasing prevalence and mortality, especially in people under the age of 25. Metformin hydrochloride (HCl), as recommended by American Diabetes Association in 2022, is the first-line therapy for type 2 diabetes in adults. Metformin has low oral bioavailability due to poor permeability. Therefore, by developing metformin HCl oral in situ gel, sustained delivery of metformin can be achieved, thus enhancing the absorption of the drug. Sodium alginate and pectin were used for formulating the system. Different adjuvant polymers, including HPMC K4M, HPMC K100 LV, PEG 4000, and SCMC were used as released-pattern-modifying agents. All formulations could afloat in 0.1 N HCl at the pH of 1.2 within a minute and stay afloat for over 8 h. The optimized formulation could be made from either sodium alginate (2%) and HPMC K4M (0.5%) or pectin (2%) and HPMC K4M (2%). The optimized formulations gradually released metformin HCl with a cumulative release of 80% within 8 h. We successfully developed floating in situ gels that can release metformin HCl sustainedly.