Micro and Nanosystems - Online First

Tacrolimus, a potent immunosuppressant, faces several limitations in transdermal delivery due to its higher molecular weight, pressing the need to encapsulate in niosomes. Various formulations (F1 to F9) were prepared using different non-ionic surfactants (Span 40, Span 60, and Brij 98) and varying cholesterol concentrations. This study aimed to evaluate the influence of surfactant type on particle size, polydispersity index, encapsulation efficiency, and in-vitro drug release.

A total of nine niosomal formulations were developed using varying ratios of drug, surfactant, and cholesterol to optimize vesicle characteristics and drug delivery performance. Three non-ionic surfactants, Span 40, Span 60, and Brij 98, were employed due to their distinct hydrophilic-lipophilic balance (HLB) and vesicle-forming abilities. The formulations were prepared by the thin film hydration method, in drug: surfactant: cholesterol ratios of 1:1:0.2, 1:1:0.4, 1:1:0.6, 1:1.5:0.3, 1:2:0.4, 1:1:0.5, 1:1:0.75, 1:1:1, and a repeat of 1:1:0.2. Each formulation was evaluated for vesicle size, zeta potential, polydispersity index (PDI), entrapment efficiency, and cumulative drug release over 24 hours. Vesicle size and PDI were measured using dynamic light scattering, while zeta potential was assessed to determine colloidal stability. Entrapment efficiency was calculated by separating the unencapsulated drug via centrifugation, and drug release was studied using a dialysis diffusion method.

Results indicated that niosomes formulated with Brij 98 exhibited significantly smaller particle size and demonstrated the highest encapsulation efficiency due to its higher hydrophilic-lipophilic balance (HLB) values than Span 40 and Span 60. Among all formulations tested, F8 (comprising Drug: Brij 98: cholesterol in a molar ratio of 1:1:0.75) showed optimal characteristics with a vesicle size of 293 ± 0.75 nm, zeta potential of -21.6 ± 0.20 mV, PDI of 0.148 ± 0.006, encapsulation efficiency of 78.36 ± 0.66%, and 71.2 ± 1.97% drug release over 24 hours.

The study demonstrates that surfactant type significantly influences the characteristics of Tacrolimus-loaded niosomes. Brij 98, due to its higher HLB and flexible chains, produced smaller vesicles with superior entrapment and stability. In contrast, Span 40 and Span 60 formed larger, less efficient vesicles. These findings underscore the importance of surfactant selection in optimizing niosomal drug delivery.

In conclusion the successful fabrication of niosomes and the achievement of desired size and uniformity crucially depend on the composition of niosomes, particularly the type of surfactant employed.

Nanosponges as a drug delivery system are solid, nanoporous structures that have a unique ability to form complexes with different types of hydrophilic and hydrophobic drug moieties that aid in drug solubility. Cilnidipine is a dihydropyridine N- and L-type calcium channel blocker used to treat hypertension. The drug belongs to BCS Class II, showing low aqueous solubility and hence requires a proper drug delivery system for enhanced therapeutic action. Nanosponges will act as an excellent drug delivery carrier to overcome such challenges. The aim is to formulate and evaluate the cilnidipine-encapsulated nano sponges for oral delivery. The study aims to enhance the solubility and control the dissolution of Cilnidipine using polyvinyl alcohol and ethyl cellulose as polymers.

Four batches of Cilnidipine nanosponges (F1-F4) were prepared using the emulsion solvent diffusion technique. The developed nanosponges were evaluated using FTIR spectroscopy analysis, DSC studies, PDI, particle size measurement, particle shape and morphological analysis, ZP determination, % yield, % EE, % DL, solubility studies, and in-vitro release studies.

The formulations’ mean particle size and zeta potential were found in the range of 212.5 - 416.1 nm and (-26.1) - (-20.8) mV, respectively. The SEM analysis confirmed the presence of spongy, irregularly shaped nanosponges with a porous surface. The results of all the evaluation parameters suggested that F1 was the best fit for all four formulations. F1 exhibited the maximum solubilization efficiency in different media, followed by F2, F3, and F4, respectively. The FTIR analysis of the F1 batch shows no significant interaction with Cilnidipine and excipients. The DSC study revealed that Cilnidipine exhibits a steep endothermic peak at 110.41°C, similar to the Cilnidipine melting temperature. In contrast, the DSC curve of the optimum formulation shows a peak at 200.65°C, which signifies the formation of an inclusion complex. The in-vitro study shows that 81.2% of the drug release was found from the optimized batch (F1). Furthermore, the release from F2, F3, & F4 was found to be 77.67, 71.96, and 58.55% respectively, whereas the drug release of the drug cilnidipine was found to be 43.04%.

The study successfully prepared and evaluated the cilnidipine-encapsulated nanosponges, aiming to enhance the solubility and in vitro profile. The optimized batch (F1) shows an excellent particle size and stability. The SEM analysis ensures the spongy and porous morphology, which contributes to enhancing the drug release. The DSC and FTIR analyses confirm the successful encapsulation of cilnidipine drug within the nanosponges with no interaction between the drug and excipient. The in vitro release study of F1 demonstrates cumulative drug release of up to 81.2%, which is comparatively higher than that of the pure drug, i.e., 43.04%, showing the potential of the nanosponge system to overcome solubility-related limitations of poorly water-soluble drugs.

The cilnidipine-encapsulated nanosponges were successfully formulated using the emulsion solvent diffusion technique. Optimized batch F1 showed the most stabilized average particle size (-26.1mV, 212.5 nm) with maximum entrapment efficiency (83.06%). The SEM analysis revealed an irregular shape and spongy structure with a porous surface, which improved the solubilization efficiency and drug release. F1 exhibits the highest solubilization and drug release (81.2%), outperforming other batches (F2, F3, F4), making it an optimal formulation.

Approximate computing is one of the techniques used to balance trade-offs between power, speed, and area in a resource-limited environment. Mainly, a large amount of power consumption and significant delay are caused by the arithmetic operations, in which the multiplication process generates more power consumption and high latency. In order to save energy and increase speed, an approximate multiplier is a good candidate for use in error-resilient applications like signal and image processing. This study proposes a truncated adaptive approximate radix-8 Booth multiplier (TAARBM). It aims to apply partial product truncation to construct an approximation multiplier design for error-tolerant applications, such as image processing.

The truncation strategy is adopted to minimize the partial product array (PPA) of the radix-8 Booth multiplier, as an additional PPA creates complexity in the operations. Moreover, the Booth encoder in the radix-8 Booth multiplier is enhanced with an Approximate Booth Encoder (ABE), which replaces adders with simple shift-logic operations to speed up the operation. The path Selectable and Reconfigurable Hybrid Adder (pSRHA) is introduced in the TAARBM architecture to minimize the delay. The design is coded in Verilog-HDL, simulated on the Xilinx Vivado simulator, and implemented on an FPGA board.

The simulation results demonstrate that the proposed 16-bit TAARBM consumes 4.110 power and 1.805 ns delay. The proposed design accomplishes error metrics of 402.96 MED, 0.00975 MRED, 1300 AED, and 0.0120 ARE.

The simulation results show the proposed design's high-speed operation. Moreover, the proposed approximate multiplier is designed with a low error rate, as shown by performing different error metrics like MED, MRED, AED, and ARE. In addition, the FIR filter is designed with the proposed TAARBM to perform the image denoising process on five benchmark images. For this application, the image quality measures, such as PSNR and SSIM, are calculated, which are higher for the proposed design.

The comparison of the obtained results with existing references proves the present validity of the current work. Various error metrics and synthesis results validate the effectiveness of the proposed approximate multiplier. Moreover, the proposed multiplier is used in an image processing application for the denoising process.

Antimicrobial resistance (AMR) is a critical global health challenge, necessitating innovative therapeutic approaches. Polyherbal formulations combined with nanotechnology offer a promising strategy to combat resistant bacterial strains. This study focuses on developing silver nanoparticles (AgNPs) using steam distillates from Terminalia chebula, Eucalyptus globulus, Morinda citrifolia, Ocimum sanctum, and Curcuma longa. These AgNPs were assessed for their antimicrobial and antioxidant properties.

Steam distillates of selected herbs were used for the green synthesis of AgNPs. Particle size, zeta potential, FTIR, and X-ray diffraction were used to characterize the nanoparticles. The antibacterial activity against ciprofloxacin-resistant E. coli was determined, and the antioxidant activity was evaluated.

The AgNPs had an optimal size of 80 nm and a zeta potential of -23 mV. Polyherbal AgNPs exhibited a 15 mm inhibition zone against resistant E. coli, surpassing that of silver nitrate.

Tulsi extract exhibited significant antioxidant properties, making AgNP-based gels a potential AMR therapy.

A microsponge is an emerging technique that has great potential to enhance the water solubility and bioavailability of poorly soluble drugs. Such a technique also has the ability to protect various drugs and their formulations that can undergo degradation in certain physiological and biological conditions. Thus, considering such quality, it can be said that the microsponge technique may be a futuristic tool that can resolve different problems associated with formulation development.

The present manuscript considers the various aspects of microsponges, like, latest research performed by different researchers, newly developed formulations, various patents related to this technique, different excipients and tools used for formulation development, and their characterization methods. For fulfilling such a purpose, a wide range of literature was taken into consideration, and analyzed to extract useful information incorporated into the manuscript. Thus, on behalf of such significant information, it can be believed that this review will open a new path for new and existing researchers who want to work on such a technique.

With this review, it is confirmed that microsponges are an effective technique that possesses the enormous potential to rectify several issues related to poor bioavailability, targeted drug delivery, dosing frequency, protection of active ingredients, and formulations in certain conditions. The different research performed in the last decade also indicated that the microsponge approach has been widely utilized to solve different concerns. But this field still needs more attention for new discoveries that may be helpful in the generation of new innovative products.

Microsponge is an innovative drug delivery method, which was initially created for topical drug administration. Later on, it was applied for oral controlled drug delivery system, transdermal drug delivery system, cosmetic products, and also for tissue engineering. This review gives confirmation that such a delivery system may provide different advantages. However, some challenges are still associated with it. Therefore, in the future, researchers need to focus on some innovative analytical tools that can ensure the quality of microsponges.

Finally, on the basis of different findings, it may be concluded that microsponges are a cutting–edge technology that offers numerous advantages. This review also confirms that microsponges may be a noteworthy tool that can develop a variety of pharmaceutical products in the future, which will be safer, effective, and patient-friendly.