Alfuzosin hydrochloride-loaded low-density gastroretentive sponges: development, in vitro characterization and gastroretentive monitoring in healthy volunteers via MRI

Cellulose ether and carbopol 971 based gastroretentive controlled release formulation design, optimization and physiologically based pharmacokinetic modeling of ondansetron hydrochloride minitablets

This study aims to design and optimize ondansetron (OND) gastro-retentive floating minitablets for better and prolonged control of postoperative nausea and vomiting (PONV) with improved patient compliance. Minitablets were directly compressed and encapsulated in a size 2 capsule shell with an overall dose of 24 mg. Central composite design (CCD) was applied keeping one cellulose ether derivative HPMC K15M and Carbopol 971 as variable and used as swelling and rate retarding agents. The other cellulose derivative i.e. sodium carboxymethyl cellulose, along with mannitol, sodium bicarbonate, and talc, were used in fixed quantities. The floating lag time, total floating time, swelling index, in-vitro drug release, and zero-order (RSQ value), were critical quality parameters. The optimized formulation (Fpred) was evaluated for all critical parameters, along with surface morphology, thermal stability, chemical interaction, and accelerated stability. The in silico PBPK modeling was applied to compare the bioavailability of Fpred with reference OND immediate-release tablets. The numerical optimization model predicted >90 % drug release with zero-order at 12 h. In silico PBPK modeling revealed comparable relative bioavailability of Fpred with the reference formulation. The gastroretentive floating minitablets of OND were successfully designed for prolonged emesis control in patients receiving chemotherapeutic agents.

Gastroretentive Technologies in Tandem with Controlled-Release Strategies: A Potent Answer to Oral Drug Bioavailability and Patient Compliance Implications

There have been many efforts to improve oral drug bioavailability and therapeutic efficacy and patient compliance. A variety of controlled-release oral delivery systems have been developed to meet these needs. Gastroretentive drug delivery technologies have the potential to achieve retention of the dosage form in the upper gastrointestinal tract (GIT) that can be sufficient to ensure complete solubilisation of the drugs in the stomach fluids, followed by subsequent absorption in the stomach or proximal small intestine. This can be beneficial for drugs that have an “absorption window” or are absorbed to a different extent in various segments of the GIT. Therefore, gastroretentive technologies in tandem with controlled-release strategies could enhance both the therapeutic efficacy of many drugs and improve patient compliance through a reduction in dosing frequency. The paper reviews different gastroretentive drug delivery technologies and controlled-release strategies that can be combined and summarises examples of formulations currently in clinical development and commercially available gastroretentive controlled-release products. The different parameters that need to be considered and monitored during formulation development for these pharmaceutical applications are highlighted.

Promising Swellable Floating Bupropion Tablets: Formulation, in vitro/in vivo Evaluation and Comparative Pharmacokinetic Study in Human Volunteers

Purpose

Bupropion is an antidepressant drug that facilitates weight loss. It is a highly water-soluble drug that needs multiple dosing, so it is considered a potential candidate for oral controlled-release dosage form. The aim of this research was to formulate and evaluate satiety-inducing swellable floating bupropion tablets by direct compression targeting depression associated with eating disorders. Various combinations of natural and semi-synthetic hydrogels were selected to achieve maximum swelling and remaining buoyant in the stomach. This synergistically enhances weight loss by increasing satiety.

Methods

An I-optimal mixture design was conducted to establish the optimal quantitative composition of tablets. Friability, floating lag time, swelling index after 4 and 8 hours, along with the percent of bupropion released at 1 and 8 hours were selected as dependent variables. The optimized formulation was characterized by physicochemical properties, thermal stability, and chemical interaction. In vivo radiographic evaluation of gastric residence besides, the oral bioavailability relative to marketed Wellbutrin^® sustained-release tablets were investigated using human volunteers.

Results

The optimized formulation (73.3 mg xanthan, 120 mg glucomannan, 8.4 mg tamarind kernel powder, 78.3 mg HPMC K15M) was achieved with the overall desirability equals 0.782. In vivo radiographic study showed that formulation was retained for >8 hours in the stomach. Compared with the marketed BUP tablets, the C_max was almost the same with a significant increase (p =0.004) for T_max.

Conclusion

Using combinations of these hydrogels would be promising gastroretentive delivery systems in the control of bupropion rate release with enhanced floating and swelling features.