Design and Evaluation of Losartan Potassium Effervescent Floating Matrix Tablets: In Vivo X-ray Imaging and Pharmacokinetic Studies in Albino Rabbits

Development and characterization of gastro-floating sustained-release granules for enhanced bioavailability of patchouli oil

Patchouli oil (PO), extracted from Pogostemon cablin Benth., a prominent aromatic plant of the Lamiaceae family, has shown considerable protective effects against gastrointestinal infections, particularly those induced by Helicobacter pylori. This study aimed to develop a gastro-floating multi-unit system for PO to enhance its gastric retention and oral bioavailability.

Methods

The oil-laden granules were prepared using colloidal silicon dioxide (CSD) for oil adsorption and to provide buoyancy, along with ethyl cellulose (EC) and hydroxypropyl methyl cellulose (HPMC) to form a sustained-release matrix. The CSD exhibited favorable characteristics for oil adsorption and floating. Compatibility between PO and CSD was affirmed through DSC thermograms and FTIR spectra. The obtained granules demonstrated a sustained release profile, achieving over 90 % release within 10 h without an initial burst. After oral administration, the granules were observed to remain in the gastric region of rats for over 7 h. The bioavailability of patchouli alcohol from the optimized granules was significantly higher than that from of the PO-loaded powders. The gastro-floating sustained-release granules, based on a CSD/EC/HPMC matrix, offer a simple yet effective strategy to improve the delivery efficacy of PO against Helicobacter pylori infections in the gastric region.

Development and characterization of pH-responsive Delonix regia/mucin co-poly (acrylate) hydrogel for controlled drug delivery of metformin HCl

This study introduces a pH-responsive hydrogel developed from Delonix regia and mucin co-poly(acrylate) through free radical polymerization to enhance controlled drug delivery systems. Characterization using FTIR, DSC, TGA, SEM, PXRD, and EDX spectroscopy detailed the hydrogel's amorphous and crystalline structures, thermal stability, surface characteristics, and elemental composition. Tested at a pH of 7.4-mimicking intestinal conditions-the hydrogel demonstrated significant swelling, indicating its capability for targeted drug release. With Metformin HCl as a model drug, the hydrogel exhibited a promising sustained release profile, underscoring its potential for oral administration. Safety and biocompatibility were assessed through acute oral toxicity studies in albino rabbits, encompassing biochemical, hematological, and histopathological evaluations. X-ray imaging confirmed the hydrogel's navigability through the gastrointestinal tract, affirming its application in drug delivery. By potentially mitigating gastrointestinal side effects, enhancing patient compliance, and improving therapeutic efficacy, this Delonix regia/mucin co-poly(acrylate) hydrogel represents a step in pharmaceutical sciences, exploring innovative materials and methodologies for drug delivery.

Expanding the Manufacturing Approaches for Gastroretentive Drug Delivery Systems with 3D Printing Technology

Gastroretentive drug delivery systems (GRDDSs) have gained substantial attention in the last 20 years due to their ability to retain the drug in the stomach for an extended time, thus promoting an extended release and high bioavailability for a broad range of active pharmaceutical ingredients (APIs) that are pH-sensitive and/or have a narrow absorption window. The currently existing GRDDSs include floating, expanding, mucoadhesive, magnetic, raft-forming, ion-exchanging, and high-density systems. Although there are seven types of systems, the main focus is on floating, expanding, and mucoadhesive systems produced by various techniques, 3D printing being one of the most revolutionary and currently studied ones. This review assesses the newest production technologies and briefly describes the in vitro and in vivo evaluation methods, with the aim of providing a better overall understanding of GRDDSs as a novel emerging strategy for targeted drug delivery.

Fabrication of gastro-floating sustained-release etoricoxib and famotidine tablets: design, optimization, in-vitro, and in-vivo evaluation

In this study, a new gastro-floating sustained-release tablet (GFT) with a combination of Etoricoxib (ET) and Famotidine (FM) was successfully developed. GFTs were prepared by using a combination of hydrophilic swellable natural/semi-synthetic polymers as a controlled-release layer. Through a 24 full factorial statistical experimental design, the effects of formulation factors on the release of GFTs were conducted. The ideal floating tablet (FT) comprised konjac-gum (150 mg), guar-gum (26.57 mg), xanthan-gum (54.17 mg), and HPMC-K15-M (69.25 mg). The ideal FT exhibited a high swelling index (SI) (297.7%) and rapid FLT (around 50 s) in 0.1 N HCl as well as controlled release of ET (22.43% in 1 h and 77.47% in 8 h) and FM (24.89% in 1 h and 93.82% in 8 h) with the absence of any drug-excipient interactions. The AUC0∼72 (ng h/mL) of ET and FM in the GFTs were approximately double-fold of the market, respectively. The relative bioavailability was (207.48 ± 12.02% and 208.51 ± 13.11%) compared with commercial tablets. The X-ray imaging showed a promising buoyancy ability for approximately 8 h. These findings revealed the successful preparation of the sustained-release floating tablet with improved dual drug delivery.

Preparation and Characterization of Theophylline Controlled Release Matrix System Incorporating Poloxamer 407, Stearyl Alcohol, and Hydroxypropyl Methylcellulose: A Novel Formulation and Development Study

BACKGROUND

Theophylline (THN), a bronchodilator with potential applications in emerging conditions like COVID-19, requires a controlled-release delivery system due to its narrow therapeutic range and short half-life. This need is particularly crucial as some existing formulations demonstrate impaired functionality. This study aims to develop a new 12-h controlled-release matrix system (CRMS) in the form of a capsule to optimize dosing intervals.

METHODS

CRMSs were developed using varying proportions of poloxamer 407 (P-407), stearyl alcohol (STA), and hydroxypropyl methylcellulose (HPMC) through the fusion technique. Their in vitro dissolution profiles were then compared with an FDA-approved THN drug across different pH media. The candidate formulation underwent characterization using X-ray diffraction, scanning electron microscopy, Fourier transform infrared spectroscopy, differential scanning calorimetry, and thermogravimetric analysis. Additionally, a comprehensive stability study was conducted.

RESULTS

In vitro studies showed that adjusting the concentrations of excipients effectively controlled drug release. Notably, the CRMS formulation 15 (CRMS-F15), which was composed of 30% P-407, 30% STA, and 10% HPMC, closely matched the 12 h controlled-release profile of an FDA-approved drug across various pH media. Characterization techniques verified the successful dispersion of the drug within the matrix. Furthermore, CRMS-F15 maintained a consistent controlled drug release and demonstrated stability under a range of storage conditions.

CONCLUSIONS

The newly developed CRMS-F15 achieved a 12 h controlled release, comparable to its FDA-approved counterpart.

Formulation and Preparation of Losartan-Potassium-Loaded Controlled-Release Matrices Using Ethocel Grade 10 to Establish a Correlation between In Vitro and In Vivo Results

In the current study, matrices of losartan potassium were formulated with two different polymers (Ethocel 10 premium and Ethocel 10FP premium), along with a filler and a lubricant, at different drug-to-polymer w/w ratios (10:3, 10:4, and 10:5). The matrices were tested by the direct compression method, and their hardness, diameter, thickness, friability, weight variation, content uniformity, and in vitro dissolution tests were assessed to determine 24-h drug release rates. The matrices with Ethocel 10 FP at a 10:4 ratio exhibited pseudo-zero-order kinetics (n-value of 0.986), while the dissolution data of the test matrices and reference tablets did not match. The new test-optimized matrices were also tested in rabbits, and their pharmacokinetic parameters were investigated: half-life (11.78 ± 0.018 h), Tmax (2.105 ± 1.131 h), Cmax (205.98 ± 0.321 μg/mL), AUCo (5931.10 ± 1.232 μg·h/mL), AUCo-inf (7348.46 ± 0.234 μg·h/mL), MRTo-48h (17.34 ± 0.184 h), and Cl (0.002 ± 0.134 mL/min). A correlation value of 0.985 between the in vitro and in vivo results observed for the test-optimized matrices was observed, indicating a level-A correlation between the percentage of the drug released in vitro and the percentage of the drug absorbed in vivo. The matrices might improve patient compliance with once-a-day dosing and therapeutic outcomes.

Nanofabrication of Losartan Potassium Sustained Release Floating Microspheres using Different Grades of Ethyl Cellulose and its Insight on Release Profiles

INTRODUCTION

A sustained release system for losartan potassium designed to delay its residence time in the stomach through the preparation of solvent evaporation technique-based floating microspheres. The influence of the different grades of Ethocel™ such as 4 cps, 10 cps, and 22 cps as well as the drug: polymer ratio on various properties of microspheres were tested.

METHODS

Thermal and functional analysis revealed no interaction between the encapsulated drug and polymer. The results indicated that the mean diameter of microspheres increased with a change in grades of ethyl cellulose relating to viscosity. However, the drug incorporation efficiency within ethyl cellulose microspheres decreased with increasing viscosity of ethyl cellulose.

RESULTS

The bulk density of the formulations was proportionally dependent on concentration and the viscosity of the polymer, which resulted in a decrease in floating capacity from 90.02% to 73.58%. Moreover, the drug release was indirectly proportional to the viscosity of ethyl cellulose tested. The in vitro release profile exhibited a burst effect with a biphasic release pattern following Fickian diffusion, indicating a diffusioncontrolled release mechanism.

CONCLUSION

The results demonstrated that the viscosity of ethyl cellulose significantly affects the floating capacity and drug release pattern from microspheres.

Improved gastric residence time of famotidine by raft-forming drug delivery system using DOE

OBJECTIVE

This study investigated the raft-forming suspension of famotidine as an anti-reflux formulation to improve the oral bioavailability of narrow absorption window drugs by enhancing gastric residence time (GRT) and preventing gastro-esophageal reflux disease (GERD).

METHOD

Various combinations of raft-forming agents, such as Tragacanth gum (TG), guar gum (GG), and xanthan gum (XG), were evaluated alongside sodium alginate (SA) to develop an effective raft. Preformulation studies and preliminary screening were conducted to identify the most suitable raft-forming agent, and GG was chosen due to its mucilaginous properties. The formulation was optimized using a 32 full factorial design, with the quantities of GG and SA as independent factors and apparent viscosity and in-vitro drug release (%) as dependent factors. The in vivo floating behavior study was performed for optimized and stabilized formulation.

RESULTS

Among the tested batches, F6 was selected as the optimized formulation. It exhibited desirable characteristics such as adequate raft weight for extended floating in gastric fluid, improved apparent viscosity, and a significant percentage of drug release at 12 h. A mathematical model was applied to the in-vitro data to gain insights into the drug release mechanism of the formulation. The stability of the suspension was assessed under accelerated conditions, and it demonstrated satisfactory stability. The formulation remains floating in the Rabbit stomach for more than 12 h.

CONCLUSION

It concludes that the developed formulation has enhanced bioavailability in the combination of GG and SA. The floating layer of the raft prevents acid reflux, and the famotidine is retained for an extended period of time in the gastric region, preventing excess acid secretion. The developed formulations are effective for stomach ulcers and GERD, with the effect of reducing acid secretion by H2 receptor antagonists.

Diltiazem Hydrochloride Floating Matrix Tablet: Formulation and in vitro-in vivo Evaluation

BACKGROUND

Diltiazem hydrochloride is a calcium channel-blocker with a plasma elimination half-life of 4.4 ± 1.3 h and has a narrow absorption window. So, this work aimed to prepare a gastro-retentive floating matrix tablet.

METHODS

The direct compression method was used to manufacture tablets. 32 factorial design was applied for optimization, taking Hydroxypropyl Methylcellulose K100M (HPMC K 100M) and the amount of sodium bicarbonate as independent factors and cumulative percentage release at 1 h, at 6 h, and at 12 h and floating lag time as dependent variables.

RESULTS

The high amount of HPMC K100M and sodium bicarbonate shows good results. The optimized preparation was evaluated for differential scanning calorimetry, in-vivo gastric retention in male albino rabbits, kinetic modeling, and stability study. An in vivo study revealed gastric retention of tablets up to 6 h in healthy male Albino rabbits. The stability study indicated no significant change in the buoyancy and release profiles of the drug.

CONCLUSION

From this study, it can be concluded that the gastro-retentive diltiazem hydrochloride floating matrix tablet was successfully prepared and retained inside the rabbit stomach for up to 6 h and was stable under accelerated stability study.

Merging konjac glucomannan with other copolymeric hydrogels as a cutting-edge liquid raft system for dual delivery of etoricoxib and famotidine

This study aimed to formulate and evaluate a floating raft system for the co-delivery of etoricoxib (ETO) and famotidine (FAM) using a combination of glucomannan with natural/semi-synthetic polysaccharides. Formulation variables affect gelation lag time (GLT), floating lag time (FLT), and release percentage of drugs after 1-8 h, Stability, and viscosity parameters were evaluated. In vivo X-ray studies, followed by the pharmacokinetic study, were performed on human volunteers. Formulations exhibited pseudoplastic behavior for ease of swallowing. The optimum raft system (ORS) comprised 1% Na alginate, 0.1% Low Methoxyl (LM) pectin, 0.8% Konjac glucomannan (KGL), 1% Precirol, and 1% CaCO3. ORS exhibited rapid GLT and FLT (around 42 and 8 sec respectively) in 0.1 N HCl as well as controlled release of ETO (15% in 1 h and 82% in 8 h) and FAM (29% in 1 h and 85% in 8 h). Formulation stability with the absence of any drug-excipient interactions was observed. The X-ray imaging showed a promising buoyancy ability for approximately 8 h. Compared with marketed products, ORS showed superior relative bioavailability for both drugs. These findings revealed the successful preparation of a promising raft system with improved dual drug delivery.

Design and evaluation of in situ gel eye drops containing nanoparticles of Gemifloxacin Mesylate

Traditional eye drops used for topically administering drugs have poor ocular bioavailability due to the biological barriers of the eye. There is an interest to design and develop novel drug delivery systems that would extend the precorneal residence time, reduce the frequency of administration and decrease dose-related toxicity. This study aimed to prepare Nanoparticles of Gemifloxacin Mesylate and incorporate them into an in situ gel. The nanoparticles were prepared by ionic gelation technique, using 3² factorial design. Sodium tripolyphosphate (STPP) was used to crosslink Chitosan. The optimized formulation of the nanoparticles (GF4) contained 0.15% Gemifloxacin Mesylate, 0.15% Chitosan and 0.20% STPP, producing 71 nm particle size and 81.11% entrapment efficiency. The prepared nanoparticles showed biphasic release, with an initial burst release of 15% in 1.0 hr and a cumulative drug release of 90.53% at the end of 24 hrs. After that, the prepared nanoparticles were incorporated into an in situ gel, using Poloxamer 407, producing a sustained drug release with efficient antimicrobial activity against gram-positive and gram-negative bacteria as confirmed by the cup plate method.

A double-layered gastric floating tablet for zero-order controlled release of dihydromyricetin: Design, development, and in vitro/in vivo evaluation

Dihydromyricetin (DHM) is an important natural flavonoid. However, most of DHM preparations have shown shortcomings such as low drug loading, poor drug stability, and/or large fluctuations in blood concentration. This study aimed to develop a gastric floating tablet with a double-layered structure for zero-order controlled release of DHM (DHM@GF-DLT). The final product DHM@GF-DLT showed a high average cumulative drug release at 24 h that best fit the zero-order model, and had a good floating ability in the stomach of the rabbit with a gastric retention time of over 24 h. The FTIR, DSC, and XRPD analyses indicated the good compatibility among the drug and the excipients in DHM@GF-DLT. The pharmacokinetic study revealed that DHM@GF-DLT could prolong the retention time of DHM, reduce the fluctuation of blood drug concentration, and enhance the bioavailability of DHM. The pharmacodynamic studies demonstrated that DHM@GF-DLT had a potent and long-term therapeutic effect on systemic inflammation in rabbits. Therefore, DHM@GF-DLT had the potential to serve as a promising anti-inflammatory agent and may develop into a once-a-day preparation, which was favorable to maintain a steady blood drug concentration and a long-term drug efficacy. Our research provided a promising development strategy for DHM and other natural products with a similar structure to DHM for improving their bioavailability and therapeutic effect.

Development of Computational In Silico Model for Nano Lipid Carrier Formulation of Curcumin

The oral delivery system is very important and plays a significant role in increasing the solubility of drugs, which eventually will increase their absorption by the digestive system and enhance the drug bioactivity. This study was conducted to synthesize a novel curcumin nano lipid carrier (NLC) and use it as a drug carrier with the help of computational molecular docking to investigate its solubility in different solid and liquid lipids to choose the optimum lipids candidate for the NLCs formulation and avoid the ordinary methods that consume more time, materials, cost, and efforts during laboratory experiments. The antiviral activity of the formed curcumin-NLC against SARS-CoV-2 (COVID-19) was assessed through a molecular docking study of curcumin's affinity towards the host cell receptors. The novel curcumin drug carrier was synthesized as NLC using a hot and high-pressure homogenization method. Twenty different compositions of the drug carrier (curcumin nano lipid) were synthesized and characterized using different physicochemical techniques such as UV-Vis, FTIR, DSC, XRD, particle size, the zeta potential, and AFM. The in vitro and ex vivo studies were also conducted to test the solubility and the permeability of the 20 curcumin-NLC formulations. The NLC as a drug carrier shows an enormous enhancement in the solubility and permeability of the drug.

Recent Progress on Modified Gum Katira Polysaccharides and Their Various Potential Applications

Gum katira polysaccharide is biocompatible and non-toxic, and has antioxidant, anti-microbial, and immunomodulatory properties. It is a natural polysaccharide and exudate derived from the stem bark of Cochlospermum reliogosum Linn. Additionally, it has many traditional medicinal uses as a sedative and for the treatment of jaundice, gonorrhea, syphilis, and stomach ailments. This article provides an overview of gum katira, including its extraction, separation, purification, and physiochemical properties and details of its characterization and pharmacognostic features. This paper takes an in-depth look at the synthetic methods used to modify gum katira, such as carboxymethylation and grafting triggered by free radicals. Furthermore, this review provides an overview of its industrial and phytopharmacological applications for drug delivery and heavy metal and dye removal, its biological activities, its use in food, and the potential use of gum katira derivatives and their industrial applications. We believe researchers will find this paper useful for developing techniques to modify gum katira polysaccharides to meet future demands.

Preparation and Characterization of Hydrophilic Polymer Based Sustained-Release Matrix Tablets of a High Dose Hydrophobic Drug

The objective of this study was the preparation and characterization of a sustained-release matrix tablet containing a high-dose hydrophobic drug and its comparison with marketed products. In the present study, HPMC was applied as the matrix-forming polymer for the sustained release of clarithromycin (500 mg). The compatibility of clarithromycin and excipients was studied using a binary mixture approach and compatible excipients were selected. Matrix tablets were prepared using the high-shear wet granulation technique. Tablets were compressed using oblong (19 mm), shallow concave punches, under a compression weight of 900 mg/tablet. The flow of granules was evaluated by determining their bulk density, tapped density, angle of repose, Hausner ratio, and Car’s index. Compressed tablets were tested for their physical parameters, mechanical characteristics, drug content, and in vitro drug release, as per United States Pharmacopeia (USP). Clarithromycin is a drug having poor water solubility and showed compatibility with all the excipients used in the formulation of polymeric matrix tablets. FTIR spectra of clarithromycin, before and after being subjected to the stress conditions, confirmed the compatibility of clarithromycin and other ingredients of the matrix tablets. All the formulations exhibited good rheological characteristics and all the parameters related to flow showed results in the acceptable range. Physically, matrix tablets were smooth and shiny, without any surface defects. Weight variation (±5%) and drug content of the tablets (95–102%) were within the pharmacopeial limits. HPMC successfully sustained the drug release for 24 h. It is concluded from the study that dissolution rate of clarithromycin can be sustained using hydrophilic polymer (HPMC) as a release-controlling agent.