Transdermal delivery of Diltiazem HCl from matrix film: Effect of penetration enhancers and study of antihypertensive activity in rabbit model

A hybrid 3D-printed and electrospun bilayer pharmaceutical membrane based on polycaprolactone/chitosan/polyvinyl alcohol for wound healing applications

Skin injuries resulting from physical trauma pose significant health risks, necessitating advanced wound care solutions. This investigation introduces an innovative bilayer wound dressing composed of 3D-printed propolis-coated polycaprolactone (PCL/PP) and an electrospun composite of polyvinyl alcohol, chitosan, polycaprolactone, and diltiazem (PVA/CTS/PCL/DTZ). SEM analysis revealed a bilayer structure with 89.23 ± 51.47 % porosity and uniformly distributed nanofibers. The scaffold tensile strength, with pore sizes of 100, 300, and 500 μm, was comparable to native skin. However, smaller pore sizes reduced water vapor transmission from 4211.59 ± 168.53 to 2358.49 ± 203.63 g/m2. The incorporation of DTZ lowered the contact angle to 35.23 ± 3.65°, while the addition of PCL reduced the degradation rate and modulated the release of DTZ by approximately 50 %. Moreover, lower pH increased the degradation rate and decreased swelling. The inclusion of propolis enhanced antibacterial activity, and 10 % DTZ promoted the viability, proliferation, and migration of fibroblasts and adipose-derived stem cells. However, increasing DTZ concentration to 12 % reduced cell viability. In vivo tests on rats demonstrated effective wound healing and anti-inflammatory properties of the bilayer samples. Regarding the aforementioned results, the PCL/PP-PVA/CTS/PCL/DTZ (10 % w/w) bilayer wound dressing is a promising candidate for wound healing applications.

Transdermal Drug Delivery Systems: Different Generations and Dermatokinetic Assessment of Drug Concentration in Skin

Transdermal drug delivery systems (TDDS) are a highly appealing and innovative method of administering drugs through the skin, as it enables the drugs to achieve systemic effects. A TDDS offers patient convenience, avoids first-pass hepatic metabolism, enables local targeting, and reduces the toxic effect of drug. This review details several generations of TDDS and the advancements made in their development to address the constraints associated with skin delivery systems. Transdermal delivery methods of the first generation have been consistently growing in their clinical application for administering small, lipophilic, low-dose drugs. Second-generation TDDS, utilizing chemical enhancers and iontophoresis, have led to the development of clinical products. Third-generation delivery systems employ microneedles, thermal ablation, and electroporation to specifically target the stratum corneum, which is the skin's barrier layer. Dermatokinetics is the study of the movement of drugs and formulations applied to the skin over a period of time. It provides important information regarding the rate and extent to which drugs penetrate skin layers. Several dermatokinetic techniques, including tape stripping, microdialysis, and laser scanning microscopy, have been used to study the intricate barrier properties and clearance mechanisms of the skin. This understanding is essential for developing and improving effective TDDS.

Pharmacodynamic Studies of Pravastatin Sodium Nanoemulsion Loaded Transdermal Patch for Treatment of Hyperlipidemia

Pravastatin sodium (PVS) is a hypolipidemic drug with poor oral bioavailability due to the first-pass effect. Therefore, this study aims to formulate and evaluate transdermal patches containing PVS-loaded nanoemulsions (PVS-NEs) to increase PVS's hypolipidemic and hepatoprotective activities. PVS-NEs were prepared using the aqueous titration method, where oleic acid was chosen as an oil phase, and span 80 and tween 80 were used as surfactant and cosurfactant respectively. Droplet size (DS), polydispersity index (PDI), zeta potential (ZP), clarity, and thermodynamic stability of NEs were all characterized. Also, PVS-NEs (NE2) with 50% oil phase, 40% SC mix 2:1, and 10% water were selected as an optimum formula based on the results of DS (251 ± 16), PDI (0.4 ± 0.16), and ZP (-70 ± 10.4) to be incorporated into a transdermal patch, and PVS-NE2 loaded transdermal patches (PVS-NE2-TDPs) were prepared by solvent evaporation method. F1 patch with HPMC E15 and PVP K30 in a ratio of 3:1 represented satisfactory patch properties with good drug-excipients compatibility. Thus, it was selected as an optimum patch formula. The optimized F1 patch was characterized for thickness, moisture content, weight variation, and drug-excipients incompatibility. Therefore, it was subjected to ex vivo skin permeation and finally pharmacodynamic studies. Ex vivo permeation studies of F1 revealed that the cumulative amount of PVS permeated across rat skin was 271.66 ± 19 µg/cm2 in 72 h, and the pharmacodynamic studies demonstrated that the F1 patch was more effective in treating hyperlipidemia than PVS-TDP (control patch) based on both blood analysis and histopathological examination. .

The Fate of 1,8-cineole as a Chemical Penetrant: A Review

The stratum corneum continues to pose the biggest obstacle to transdermal drug delivery. Chemical penetrant, the first generation of transdermal drug delivery system, offers a lot of potential. In order to fully examine the permeation mechanism of 1,8-cineole, a natural monoterpene, this review summarizes the effects of permeation-enhancing medications on drugs that are lipophilic and hydrophilic as well as the toxicity of this substance on the skin and other tissues. For lower lipophilic drugs, 1,8-cineole appears to have a stronger osmotic-enhancing impact. An efficient and secure tactic would be to combine enhancers and dose forms. 1,8-cineole is anticipated to be further developed in the transdermal drug delivery system and even become a candidate drug for brain transport due to its permeability and low toxicity.

Natural polysaccharide-based biodegradable polymeric platforms for transdermal drug delivery system: a critical analysis

Natural biodegradable polymers generally include polysaccharides (starch, alginate, chitin/chitosan, hyaluronic acid derivatives, etc.) and proteins (collagen, gelatin, fibrin, etc.). In transdermal drug delivery systems (TDDS), these polymers play a vital role in controlling the device's drug release. It is possible that natural polymers can be used for TDDS to attain predetermined drug delivery rates due to their physicochemical properties. These polymers can be employed to market products and scale production because they are readily available and inexpensive. As a result of these polymers, new pharmaceutical delivery systems can be developed that is both regulated and targeted. The focus of this article is the application of a biodegradable polymeric platform based on natural polymers for TDDS. Due to their biocompatibility and biodegradability, natural biodegradable polymers are frequently used in biomedical applications. Additionally, these natural biodegradable polymers are being studied for their characteristics and behaviors.

Poly (vinyl alcohol) copolymerized with xanthan gum/hypromellose/sodium carboxymethyl cellulose dermal dressings functionalized with biogenic nanostructured materials for antibacterial and wound healing application

Effective treatment of infected wounds requires a comprehensive wound dressing with a combination of antibacterial, antioxidative, and anti-inflammatory effects. Biodegradable wound dressings incorporating nanostructured material were developed using polyvinyl alcohol with xanthan gum, hypromellose, or sodium carboxymethyl cellulose and extensively evaluated for antibacterial and wound healing efficacy. Synthesized silver nanoparticles and wound dressings displayed λ_max at 420 nm with zeta potential ≈ - 35 mV. Significant growth inhibition with >99 % reduction in CFU/ml (p < 0.05) against important wound pathogens including Acinetobacter baumannii, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Staphylococcus aureus, Staphylococcus epidermidis, and Candida albicans were observed. Within 1 h of treatment, hypromellose nanocomposite demonstrated excellent bactericidal effects with a 99.9 % of reduction in growth. In addition, wound dressings demonstrated inhibitory activities against free radical scavengers. Wound dressings demonstrated a significant reduction in the inflammatory response in RAW 264.7 macrophages (p < 0.001). Ex-vivo diffusion demonstrated zero-order release and steady-state flux between 0.1571-0.2295 μg/ml/cm²h with 0.124-0.144 permeability coefficient after 10 h. Usage in animals further confirmed that the hypromellose nanocomposite accelerated the wound healing process with biocompatibility. The results suggested that hybrid biodegradable dressings can be effectively applied to treat infected wounds and attenuate inflammatory responses.

Development, optimization and characterization of flurbiprofen matrix transdermal drug delivery system using Box–Behnken statistical design

Background

Present investigation for research was to develop matrix-type transdermal drug delivery system of flurbiprofen (FBP) with the various ratio of matrix polymers (hydrophilic and hydrophobic), the concentration of plasticizer and natural penetration enhancer by Box–Behnken statistical design to investigate the combined outcome of selected independent variables for effective management of rheumatoid arthritis.

The influence of a binary mixture of polymers, plasticizer and penetration enhancer on physicochemical considerations including thickness, tensile strength, percent elongation, weight variation, percent moisture content, percent moisture uptake, water vapour transmission rate, folding endurance, drug content, in vitro drug dissolution study and then ex vivo drug permeation study was evaluated.

Results

The study demonstrated that the tensile strength of films improved by matrix polymer ratio and to a slighter gradation in the rise of plasticizer and natural penetration enhancer. Ex vivo drug permeation study was accompanied via excised porcine skin as a permeation barrier in Franz diffusion cell. Ex vivo drug permeation study indicated that matrix polymer ratio (HPMC K15M:ERL100) at 3:1 and natural penetration enhancer (d-limonene) at highest concentration 7.5% w/w containing formulation FBPT7 delivered maximum flux and supplementary improved the permeation of drug. The result of the skin irritation test revealed that the developed formulation is free from any type of skin irritation effects like erythema and oedema.

Conclusion

Based on the findings of this research, it can be established that a well-controlled release and very effective skin penetration of the drug was accomplished by the film FBPT7 in the existence of permeation enhancers for prolonged periods.

Diltiazem-loaded electrospun nanofibers as a new wound dressing: fabrication, characterization, and experimental wound healing

Calcium channel blockers such as diltiazem have recently been investigated for their wound-healing potential. The aims of this study were to fabricate diltiazem-loaded nanofibers for a new wound dressing and investigate their beneficial properties for wound healing. Nanofibers were electrospun using polyvinyl alcohol solution containing 0, 2 or 4% diltiazem. Fibers were characterized in terms of physicochemical properties, drug release and fibroblast viability, and in animal wound healing assays. Compared to other formulations, nanofibers containing 4% diltiazem showed thin fiber size (152.7 nm), high porosity (88.4%), high swelling (110.4%), low water contact angle (29.1°) and little weight loss (17.3%). Drug release from 4%-diltiazem nanofibers showed good fit to a Korsmeyer-Peppas model, suggesting a non-Fickian release mechanism (R ² = 96%, n = 0.52). In vitro, 4%-diltiazem mats were not cytotoxic and enhanced fibroblast proliferation by 263% after 5 days of treatment compared to control. In vivo, wounds treated with this mat for 14 days showed the smallest size (14.7%) and better histopathologic characteristics compared to other wounds. The 4%-diltiazem mat also demonstrated significant antioxidant activity by reducing tissue MDA and nitrite levels by 63 and 59% compared to normal saline. The findings support the eligibility of this novel wound dressing for additional clinical research.

In situ microemulsion-gel obtained from bioadhesive hydroxypropyl methylcellulose films for transdermal administration of zidovudine

This study aims to develop in situ microemulsion-gel (ME-Gel) obtained from hydroxypropyl methylcellulose (HPMC) films for transdermal administration of Zidovudine (AZT). Firstly, HPMC films containing propylene glycol (PG) and eucalyptus oil (EO) were obtained and characterized. Later, a pseudo-ternary phase diagram composed of water, EO, tween 80 and PG was obtained and one microemulsion (ME) with a similar proportion of the film components was obtained. ME was transformed in ME-Gel by the incorporation of HPMC. Finally, HPMC films were hydrated with Tween 80 solution to yield in situ ME-Gel and its effect on AZT skin permeation was compared with HPMC film hydrated with water (F5_hyd). The results showed that the ME and ME-Gel presented a droplet size of 16.79 and 122.13 μm, respectively, polydispersity index (PDI) < 0.39 and pH between 5.10 and 5.40. The incorporation of HPMC resulted in viscosity about 2 times higher than the use of ME. The presence of AZT did not alter the formulation properties. The in situ ME-Gel promoted a two-fold increase in the permeated amount of AZT compared to F5_hyd. The results suggest that it was possible to obtain an ME-Gel in situ from HPMC films and that its effect on transdermal permeation of AZT was significant.

Design and optimization of film-forming gel of etoricoxib using research surface methodology

The present investigation is focused on the development of transdermal film-forming gel (FFG) loaded with etoricoxib employing research surface methodology (RSM). Box-Behnken surface design method was used to develop experimental run using different concentrations of etoricoxib, hydroxypropyl methylcellulose (HPMC K100M), and eudragit RL100 as independent variables, and Derringer's optimization tool was employed to optimize best possible formulation. The dependent variables considered in this study were viscosity and drug permeation at 24 h (Q24, μg/cm²). Anti-inflammatory study was performed on Wistar albino rats for 8 h. Skin irritation studies and accelerated stability studies were performed for validated FFG formulations. Quadratic model was found to be best fit model (p < 0.0001) for both the responses. The influence of HPMC concentration on the viscosity was found to be highest whereas concentration of etoricoxib was maximum for Q24. The optimum composition of the FFG was observed to be 4% of etoricoxib, 1.1246% of HPMC, and 0.4% of eudragit. Above composition resulted in viscosity of 1549.5 mPa.s and maximum Q24 of 4639.11 μg/cm² with desirability 0.918. The in vivo anti-inflammatory study demonstrated better sustained release effect (for 8 h) of optimized FFG compared to orally administered drug suspension. An average irritation score of 0.555 was observed on Draize scoring system. The validated FFG formulation was found to be stable for the 3 months in accelerated conditions. It can be concluded from the above investigations that the validated FFG formulation of etoricoxib is well tolerated and could provide sustained drug release for 8 h. Graphical abstract.

Development of an optimized avanafil-loaded invasomal transdermal film: Ex vivo skin permeation and in vivo evaluation

Avanafil (AVA) is a recent FDA approved selective phosphodiesterase type 5 inhibitor used for oral treatment of erectile dysfunction. The oral bioavailability of the drug is challenged by its reduced water solubility, considerable presystemic metabolism, and altered absorption in the presence of food. Accordingly, this work aimed to surmount the aforementioned challenges through the development of optimized nanosized AVA invasomes with enhanced transdermal delivery. AVA invasomes were prepared according to a Box-Behnken experimental design to explore the impact of the following formulation factors: phospholipid % (X₁), ethanol % (X₂), terpene % (X₃), and terpene type (X₄) on vesicle size (Y₁) and entrapment efficiency (Y₂). The three numerical variables were used at three levels, while the categorical variable was used at two levels. The optimized formulation with vesicular size of 109.92 nm and entrapment efficiency of 96.98% was incorporated into a hydroxypropyl methyl cellulose-based transdermal film and characterized for its ex vivo permeation behavior and in vivo performance in rats. The optimized AVA invasomal film showed enhanced ex vivo permeation with an enhancement factor of 2.514 and a more than four-fold increase in relative bioavailability compared to the raw AVA film. These results provide insight into the capability of the optimized invasomal film to enhance the transdermal permeation and bioavailability of AVA.

The Influence of Microneedles on the Percutaneous Penetration of Selected Antihypertensive Agents: Diltiazem Hydrochloride and Perindopril Erbumine

BACKGROUND

It is well documented in the scientific literature that high blood pressure can lead to cardiovascular disease. Untreated hypertension has clinical consequences such as coronary artery disease, stroke or kidney failure. Diltiazem hydrochloride (DH), a calcium-channel blocker, and perindopril erbumine (PE), an inhibitor of the angiotensin converting enzyme are used for the management of hypertension.

OBJECTIVE

This project will examine the effect of microneedle rollers on the transport of DH and PE across pig ear skin. The use of the transcutaneous route of administration reduces and in sometimes eliminates the trauma and pain associated with injections. Furthermore, there is increased patient compliance. The purpose of this project was to study the effect of stainless steel microneedles on the transdermal delivery of DH and PE.

METHOD

We utilized vertical Franz diffusion cells to study in vitro transport of DH and PE across microneedle- treated pig ear skin. Confocal laser scanning microscopy (CLSM) was used to characterize microchannel depth. Transdermal flux values were determined from the slope of the linear portion of the cumulative amount versus time curve.

RESULTS

There was a 113.59-fold increase in the transdermal permeation of DH following the application of microneedle roller compared to passive diffusion.

CONCLUSION

In the case of PE, there was an 11.99-fold increase in the drug transport across pig skin following the application of microneedle rollers in comparison with passive diffusion. Student's t-test and Mann-Whitney's rank sum test were used to determine statistically significant differences between experimental and control groups.

TRPA1-dependent reversible opening of tight junction by natural compounds with an α,β-unsaturated moiety and capsaicin

The delivery of hydrophilic macromolecules runs into difficulties such as penetration of the cell membrane lipid bilayer. Our prior experiment demonstrated that capsaicin induces the reversible opening of tight junctions (TJs) and enhances the delivery of hydrophilic macromolecules through a paracellular route. Herein, we screened paracellular permeability enhancers other than capsaicin. As TJ opening by capsaicin is associated with Ca²⁺ influx, we first screened the compounds that induce Ca²⁺ influx in layered MDCK II cells, and then we determined the compounds' abilities to open TJs. Our results identified several natural compounds with α,β-unsaturated moiety. A structure-activity relationship (SAR) analysis and the results of pretreatment with reducing reagent DTT suggested the importance of α,β-unsaturated moiety. We also examined the underlying mechanisms, and our findings suggest that the actin reorganization seen in capsaicin treatment is important for the reversibility of TJ opening. Furthermore, our analyses revealed that TRPA1 is involved in the Ca²⁺ influx and TJ permeability increase not only by an α,β-unsaturated compound but also by capsaicin. Our results indicate that the α,β-unsaturated moiety can be a potent pharmacophore for TJ opening.

In vitro and in vivo investigation for optimization of niosomal ability for sustainment and bioavailability enhancement of diltiazem after nasal administration

Diltiazem hydrochloride (DTZ) is a calcium channel antagonist depicted by extensive first pass metabolism and low oral bioavailability. The aim of this work was to develop niosomes for potential nasal delivery of DTZ. Niosomes protect hydrophilic drugs inside their core while nasal route offers both rapid onset and evasion of first-pass metabolism. Niosomes were prepared using a combination of Span 60 or Brij-52 with cholesterol (CHOL) in different molar ratios followed by determination of entrapment efficiency, particle size and in vitro drug release. A parallel design was adopted to evaluate the pharmacokinetic performance of DTZ-loaded niosomes in male Wistar rats. Non-compartmental analysis was performed where Cmax, Tmax, t1/2, MRT, area under the release curve (AUC) and Ke were assessed. The prepared niosomes were spherical with mean particle size 0.82-1.59 μm. Span 60-cholesterol niosomes (1:1 molar ratio) showed the highest entrapment and release efficiencies. In vivo study revealed an increase in MRT, t1/2 and AUC with a decrease in Ke. In conclusion, nasal niosomal formulation of DTZ expressed suitable pharmacokinetic parameters and bioavailability through prolonged duration of action inside the body as well as low rate of elimination depicting a promising alternate to the conventional oral route.

Fabrication of a Ti porous microneedle array by metal injection molding for transdermal drug delivery

Microneedle arrays (MA) have been extensively investigated in recent decades for transdermal drug delivery due to their pain-free delivery, minimal skin trauma, and reduced risk of infection. However, porous MA received relatively less attention due to their complex fabrication process and ease of fracturing. Here, we present a titanium porous microneedle array (TPMA) fabricated by modified metal injection molding (MIM) technology. The sintering process is simple and suitable for mass production. TPMA was sintered at a sintering temperature of 1250°C for 2 h. The porosity of TPMA was approximately 30.1% and its average pore diameter was about 1.3 μm. The elements distributed on the surface of TPMA were only Ti and O, which may guarantee the biocompatibility of TPMA. TPMA could easily penetrate the skin of a human forearm without fracture. TPMA could diffuse dry Rhodamine B stored in micropores into rabbit skin. The cumulative permeated flux of calcein across TPMA with punctured skin was 27 times greater than that across intact skin. Thus, TPMA can continually and efficiently deliver a liquid drug through open micropores in skin.