Effervescent tablet formulation for enhanced patient compliance and the therapeutic effect of risperidone

20-Week intramuscular toxicity study of rotigotine behenate extended-release microspheres for injection via intramuscular injection in cynomolgus monkeys

Continuous dopaminergic stimulation (CDS) has become an important strategy for the development of drugs to treat Parkinson's disease (PD). Rotigotine behenate extended-release microspheres (RBEM) for injection represents a new treatment regime for CDS and is being applied for clinical trial. Our study in cynomolgus monkeys was a 20-week repeat dose toxicity investigation with RBEM at dosages of 90, 180, 360, with a 12-week recovery period. The results observed some irritations in the application site and surrounding tissues in Placebo microspheres and each dose of RBEM, was accompanied with increased white blood count and fibrinogen. RBEM-treated monkeys were additionally noted with a pharmacological action-related decrease in prolactin. These findings showed certain reversibility after the 12-week recovery phase. No clear sex difference was noted in the plasma exposure to rotigotine. The exposure generally increased in a dose-proportional manner. In summary, major toxicological effects are associated with the dopamine agonist-related properties of rotigotine, and the removal of foreign bodies caused by p oly (lactide-co-glycolide) (PLGA)and sodium carboxymethyl cellulose (SCMC), and the no-observed-adverse-effect-level (NOAEL) was 360 mg/kg.

Exploring Applications of Flexible Vesicular Systems as Transdermal Drug Delivery

Deformable lipidic-nano carriers are a category of advanced liposomal formulations. Deformable lipidic-nano carriers have a specific character to transform by rearranging the lipidic backbone to squeeze themself through a pore opening ten times smaller than their diameter when exposed to a variable condition like hydration gradient as these have potentially been used as a non-invasive delivery system to transdermally migrate various therapeutic agents for over three decades. Despite their vast application in transdermal drug delivery system, non-uniformity to express their chemical nature still exist and authors use various terms synonymously and interchangeably with each other. The present study delineates the terminologies used to express different derived deformable vesicular carriers to harmonize the terminological use. It also includes the effectiveness of deformable nanocarriers like Transferosomes, Ethosomes, Menthosomes, Invasomes, and Glycerosomes in skin conditions like basal cell carcinoma, fungal and viral infections, and hyperpigmentation disorders, along with others. Various review and research articles were selected from the 'Pubmed' database. The keywords like Transferosomes, Flexi-vesicular system, ultra-deformable vesicles, and nano-vesicular systems were used to extract the data. The data was reviewed and compiled to categorically classify different flexible vesicular systems. The composition of the different vesicular systems is identified and a report of various pathological conditions where the use of flexible lipid nanocarrier systems was implemented is compiled. The review also offers suggestive approaches where the applicability of these systems can be explored further.

A Highly Efficacious Electrical Biofilm Treatment System for Combating Chronic Wound Bacterial Infections

Biofilm infection has a high prevalence in chronic wounds and can delay wound healing. Current treatment using debridement and antibiotic administration imposes a significant burden on patients and healthcare systems. To address their limitations, a highly efficacious electrical antibiofilm treatment system is described in this paper. This system uses high-intensity current (75 mA cm-2 ) to completely debride biofilm above the wound surface and enhance antibiotic delivery into biofilm-infected wounds simultaneously. Combining these two effects, this system uses short treatments (≤2 h) to reduce bacterial count of methicillin-resistant S. aureus (MRSA) biofilm-infected ex vivo skin wounds from 1010 to 105.2 colony-forming units (CFU) g-1 . Taking advantage of the hydrogel ionic circuit design, this system enhances the in vivo safety of high-intensity current application compared to conventional devices. The in vivo antibiofilm efficacy of the system is tested using a diabetic mouse-based wound infection model. MRSA biofilm bacterial count decreases from 109.0 to 104.6 CFU g-1 at 1 day post-treatment and to 103.3 CFU g-1 at 7 days post-treatment, both of which are below the clinical threshold for infection. Overall, this novel technology provides a quick, safe, yet highly efficacious treatment to chronic wound biofilm infections.

Transdermal Delivery of Telmisartan: Formulation, in vitro, ex vivo, Iontophoretic Permeation Enhancement and Comparative Pharmacokinetic Study in Rats

Purpose

The purpose of this study was to prepare telmisartan transethosomes, incorporate them into a gel, evaluate them for in vitro drug release and in vivo permeation using iontophoresis to enhance their transdermal delivery.

Materials and Methods

TE formulae were prepared using various surfactants (SAAs), different ethanol concentrations, and different phospholipid-to-SAA ratios with different cholesterol ratios, characterized according to their entrapment efficiency percentage (EE%), zeta potential (ZP), particle size (PS), and polydispersity index (PDI). The optimum three formulae were incorporated into a gel, evaluated physically, in vitro dissolution, and ex vivo drug permeation using rat skin and Iontophoresis was performed on the best formula.

Results

The optimum three formulae (F29, F31, F32) had an EE% of 97±0.26%, 89±0.25% and 88±0.17%, PS of 244±5.88 nm, 337±4.6 nm and 382.2±3.06 nm, PDI of 0.57±1.9, 0.5±1.4 and 0.63±2.2 and ZP of −31.6±1.59 mV, −28.3±3.79 mV and −31±5.65, respectively. Selecting F29 for in vivo study by iontophoretic enhancement, Cmax was increased by 1.85 folds compared to the commercial oral tablet and by 1.5 folds compared to transdermal gel. Tmax decreased by half using iontophoresis compared to commercial tablets and transdermal gel.

Conclusion

The transethosomal formulation of telmisartan enhanced its transdermal absorption and increased its bioavailability as well. Iontophoresis was used to increase maximum plasma concentration and reduce Tmax by half.

Vancomycin-Loaded Microneedle Arrays against Methicillin-Resistant Staphylococcus Aureus Skin Infections

Skin and soft tissue infections (SSTIs) caused by methicillin-resistant Staphylococcus aureus (MRSA) are a major healthcare burden, often treated with intravenous injection of the glycopeptide antibiotic vancomycin (VAN). However, low local drug concentration in the skin limits its treatment efficiency, while systemic exposure promotes the development of resistant bacterial strains. Topical administration of VAN on skin is ineffective as its high molecular weight prohibits transdermal penetration. In order to implement a local VAN delivery, microneedle (MN) arrays with a water-insoluble support layer for the controlled administration of VAN into the skin are developed. The utilization of such a support layer results in water-insoluble needle shafts surrounded by drug-loaded water-soluble tips with high drug encapsulation. The developed MN arrays can penetrate the dermal barriers of both porcine and fresh human skin. Permeation studies on porcine skin reveal that the majority of the delivered VAN is retained within the skin. It is shown that the VAN-MN array reduces MRSA growth both in vitro and ex vivo on skin. The developed VAN-MN arrays may be extended to several drugs and may facilitate localized treatment of MRSA-caused skin infections while minimizing adverse systemic effects.

Transdermal iontophoresis delivery system for terazosin hydrochloride: an in vitro and in vivo study

This study aimed to construct a transdermal iontophoresis delivery system for terazosin hydrochloride (IDDS-TEH), which included a positive and negative electrode hydrogel prescription. Intact guinea pig skin was used as a model for the skin barrier function, and the current intensity, terazosin hydrochloride (TEH) concentration, pH, competitive salt, and transdermal enhancer properties were studied. The blood drug concentration was determined in Sprague–Dawley (SD) rats using HPLC, and the antihypertensive effects of IDDS-TEH were evaluated in spontaneously hypertensive rats (SHRs). The results showed that the steady-state penetration rate of TEH increased (from 80.36 µg·cm⁻²·h⁻¹ to 304.93 µg·cm⁻²·h⁻¹), followed by an increase in the current intensity (from 0.10 mA·cm⁻² to 0.49 mA·cm⁻²). The pH values also had a significant influence on percutaneous penetration. The blood concentration of IDDS-TEH was significantly higher (p < .05) than with passive diffusion, which could not be detected. The main pharmacokinetic parameters of the high current group (0.17 mA·cm⁻²) and the low current group (0.09 mA·cm⁻²) were AUC_0–t: 5873.0 ng·mL⁻¹·h and 2493.7 ng·mL⁻¹·h, respectively. Meanwhile, the pharmacodynamic results showed that IDDS-TEH significantly decreased the blood pressure of SHRs compared with the TEH hydrogel without loading current. Therefore, TEH could be successfully delivered by the transdermal iontophoresis system in vitro and in vivo, and further clinical studies should be explored to develop a therapeutically useful protocol.

Diacerein solid dispersion loaded tablets for minimization of drug adverse effects: statistical design, formulation, in vitro, and in vivo evaluation

Diacerein is a BCS class II drug employed in osteoarthritis management. The acid/base hydrolysis of the unabsorbed diacerein in the colon is responsible for its laxative effect. Therefore, this work aimed to enhance the solubility, dissolution, and oral bioavailability of diacerein. Such enhancement means lower doses and fewer gastrointestinal adverse effects. A 4¹.3¹.2¹ full factorial design was adopted to prepare 24 solid dispersion formulae. Solid-state characterization showed the dissolution of diacerein crystals as metastable amorphous or microcrystalline forms in a matrix system that enhanced the drug dissolution. Desirability factor suggested compounding an optimized formula (F1) of Pluronic^®F68 with 1:3 drug:carrier ratio using rotavap that showed higher drug solubility (187.61 µg/mL) than drug powder (22.5 µg/mL). It achieved higher dissolution efficiency (4.04-fold) and rate (6.6-fold) as well as 100% release in 2 min. F1 was compressed into tablets recording greater dissolution efficiency (1.24-fold) and rate (12.5-fold) than the marketed product. The prepared tablet accomplished a 2.66-fold enhancement in diacerein bioavailability compared to the marketed product. In conclusion, the formulation of diacerein as solid dispersion loaded tablets could be of added value for the treatment of osteoarthritis in terms of enhanced patient compliance. Solid dispersion is an easy and scalable technique.

Lipid Vesicles and Nanoparticles for Non-invasive Topical and Transdermal Drug Delivery

The delivery of drugs, via different layers of skin, is challenging because it acts as a natural barrier and exerts hindrance against molecules to permeate into or through it. To overcome such obstacles, different noninvasive methods, like vehicle-drug interaction, modifications of the horny layer and nanoparticles have been suggested. The aim of the present review is to highlight some of the non-invasive methods for topical, diadermal and transdermal delivery of drugs. Special emphasis has been made on the information available in numerous research articles that put efforts in overcoming obstacles associated with barrier functions imposed by various layers of skin. Advances have been made in improving patient compliance that tends to avoid hitches involved in oral administration. Of particular interest is the use of lipid-based vesicles and nanoparticles for dermatological applications. These particulate systems can effectively interact and penetrate into the stratum corneum via lipid exchange and get distributed in epidermis and dermis. They also have the tendency to exert a systemic effect by facilitating the absorption of an active moiety into general circulation.

Fabrication of Mucoadhesive-Dendrimers as Solid Dosage Forms

Mucoadhesion has a potential role in the delivery of pharmaceutical medicaments via various routes of administration, viz. oral, nasal, vaginal, and buccal. Mucoadhesion provides controlled drug delivery, sustained drug delivery, and local or site-specific drug delivery. This chapter focuses on the mechanism of bio-adhesion to glycoprotein layer of mucosal membrane. Some of the gastric mucoadhesive solid dosage forms of nanocarrier, viz. nanoparticle, microsphere, and nanofibers, undergo evaluation of mucoadhesive parameters. That includes mucoadhesive strength, tensile strength, swelling index, stability studies, in vivo study, etc. The oral route is the most desirable way among intravenous, subcutaneous, intramuscular, intranasal, intravaginal, etc. for drug delivery and because of patient compliance. One of the novel approaches is where nanocarrier is loaded in the solid dosage form for effective drug action and enhanced local delivery of a drug. Mainly this chapter explains about dendrimer-based oral solid dosage form (tablet) employing mucoadhesive polymers with an aim to improve retention time of drug at desired sites. Dendrimer-loaded mucoadhesive tablets promise controlled drug delivery with a gastro-retentive property, higher drug incorporation, ease of formulation development, and accessible absorption, owing to adjacent interaction with a biological membrane and prolonged retention to mucosa providing higher bioavailability of drugs.