Design, Development, and Optimization of Dexibuprofen Microemulsion Based Transdermal Reservoir Patches for Controlled Drug Delivery

Preparing a novel baicalin-loaded microemulsion-based gel for transdermal delivery and testing its anti-gout effect

We previously demonstrated that baicalin had efficacy against gouty arthritis (GA) by oral administration. In this paper, a novel baicalin-loaded microemulsion-based gel (B-MEG) was prepared and assessed for the transdermal delivery of baicalin against GA. The preparation method and transdermal capability of B-MEG was screened and optimized using the central composite design, Franz diffusion cell experiments, and the split-split plot design. Skin irritation tests were performed in guinea pigs. The anti-gout effects were evaluated using mice. The optimized B-MEG comprised of 50 % pH 7.4 phosphate buffered saline, 4.48 % ethyl oleate, 31.64 % tween 80, 13.88 % glycerin, 2 % borneol, 0.5 % clove oil and 0.5 % xanthan gum, with a baicalin content of (10.42 ± 0.08) mg/g and particle size of (15.71 ± 0.41) nm. After 12 h, the cumulative amount of baicalin permeated from B-MEG was (672.14 ± 44.11) μg·cm-2. No significant skin irritation was observed following B-MEG application. Compared to the model group, B-MEG groups significantly decreased the rate of auricular swelling (P < 0.01) and number of twists observed in mice (P < 0.01); and also reduced the rate of paw swelling (P < 0.01) and inflammatory cell infiltration in a mouse model of GA. In conclusion, B-MEG represents a promising transdermal carrier for baicalin delivery and can be used as a potential therapy for GA.

Strategies to Improve the Transdermal Delivery of Poorly Water-Soluble Non-Steroidal Anti-Inflammatory Drugs

The transdermal delivery of non-steroidal anti-inflammatory drugs (NSAIDs) has the potential to overcome some of the major disadvantages relating to oral NSAID usage, such as gastrointestinal adverse events and compliance. However, the poor solubility of many of the newer NSAIDs creates challenges in incorporating the drugs into formulations suitable for application to skin and may limit transdermal permeation, particularly if the goal is therapeutic systemic drug concentrations. This review is an overview of the various strategies used to increase the solubility of poorly soluble NSAIDs and enhance their permeation through skin, such as the modification of the vehicle, the modification of or bypassing the barrier function of the skin, and using advanced nano-sized formulations. Furthermore, the simple yet highly versatile microemulsion system has been found to be a cost-effective and highly successful technology to deliver poorly water-soluble NSAIDs.

In vitro and Ex vivo study targeting the development of a Lavandula stoechas L. (Ustukhuddūs) loaded Unani Transdermal patch: Implication of Unani Medicine in the treatment of Nisyan (Dementia)

Ustukhuddūs (Lavandula stoechas L.) has been extensively used orally and topically in treating various neurological disorders, including dementia. The optimum potential of traditional dosage forms of Ustukhuddūs is limited for various reasons. Transdermal drug delivery system (TDDS) is a novel means of drug delivery and is known to overcome the drawbacks associated with traditional dosage forms. The current study aimed at fabricating and evaluating Ustukhuddūs hydro-alcoholic extract (UHAE) and essential oil (UEO) loaded matrix-type transdermal patches having a combination of hydrophilic - hydroxyl propyl methyl cellulose (HPMC) and hydrophobic - ethyl cellulose (EC) polymers. ATR-FTIR, DSC, XRD, and SEM analysis were carried out to study drug-polymer interactions, confirming the formation of developed patches and drug compatibility with excipients. We assessed the fabricated patches to evaluate their physicochemical properties, in vitro drug release, and permeation characteristics via ex vivo experiments. The physicochemical characteristics of patches showcased the development of good and stable films with clarity, smoothness, homogeneity, optimum flexibility and free from causing skin irritancy or sensitization. In vitro drug release and ex vivo permeation profile of developed patches were evaluated employing Franz diffusion cells. UHAE and UEO patches exhibited a cumulative drug release of 81.61 and 85.24 %, respectively, in a sustained-release manner and followed non-Fickian release mechanisms. The ex vivo permeation data revealed 66.82 % and 76.41 % of drug permeated from UHAE and UEO patches, respectively. The current research suggests that the formulated patches are more suitable for TDDS and hold potential significance in the treatment of dementia, contributing to enhanced patient compliance, thereby highlighting the implication of Unani Medicine in Nisyan (Dementia) treatment.

Improvement in Skin Penetration Capacity of Linalool by Using Microemulsion as a Delivery Carrier: Formulation Optimization and In Vitro Evaluation

Linalool is an aromatic oil with analgesic, anti-inflammatory and anti-UVB-induced skin damage effects. The aim of this study was to develop a linalool-loaded microemulsion formulation for topical application. In order to quickly obtain an optimal drug-loaded formulation, statistical tools of the response surface methodology and a mixed experimental design with four independent variables of oil (X₁), mixed surfactant (X₂), cosurfactant (X₃) and water (X₄) were used to design a series of model formulations in order to analyze the effect of the composition on the characteristics and permeation capacity of linalool-loaded microemulsion formulations and to obtain an appropriate drug-loaded formulation. The results showed that the droplet size, viscosity and penetration capacity of linalool-loaded formulations were significantly affected by formulation component proportions. The skin deposition amount of the drug and flux of such formulations expressively increased about 6.1-fold and 6.5-fold, respectively, when compared to the control group (5% linalool dissolved in ethanol). After 3 months of storage, the physicochemical characteristics and drug level did not show a significant change. The linalool formulation-treated rat skin showed non-significant irritation compared to skin treatments in the distilled-water-treated group. The results showed that specific microemulsion applications might be considered as potential drug delivery carriers for essential oil topical application.

Development of Oral Microemulsion Spray Containing Pentacyclic Triterpenes-Rich Centella asiatica (L.) Urb. Extract for Healing Mouth Ulcers

Several publications have shown that Centella asiatica (L.) Urb. and its active constituents (pentacyclic triterpenes) are effective in wound healing. The pentacyclic triterpenes-rich C. asiatica extract (PRE) was prepared following a previous study by microwave-assisted extraction (MAE) and fractionation with macroporous resin. This method provided the pentacyclic triterpene content in the extract up to 59.60% w/w. The PRE showed potent anti-inflammatory activity by inhibiting nitric oxide (NO) production with an IC50 value of 20.59 ± 3.48 μg/mL and a potent fibroblast proliferative effect (165.67%) at concentrations of 10 μg/mL. The prepared microemulsion consisted of a water: oil: surfactant mixture of 2: 2: 6, using coconut oil: clove oil (1:1) as the oil phase and Tween 20: Span 20 (2:1) as the surfactant mixture and 1.0, 2.5, and 5.0% PRE. Cell proliferation, migration, and collagen production of the microemulsion base and microemulsions containing 1.0%, 2.5%, and 5.0% PRE were evaluated. The results revealed that the microemulsion containing 1% PRE had the highest proliferation effect (136.30 ± 3.93% to 152.65 ± 3.48% at concentrations of 10 μg/mL), migration activities (100.00 ± 0.0% at 24 h), and collagen production in human dermal fibroblast (HDF) and human gingival fibroblast (HGF) cells when compared with other formulations or blank. Moreover, the anti-inflammatory activity of microemulsions containing 1% PRE was slightly lower than standard indomethacin. Anti-inflammation of the microemulsion containing PRE exhibited a dose-dependent trend, while 5% PRE was more potent than the standard drug. Considering the potent wound-healing activities and the good anti-inflammatory activity of the microemulsion containing PRE, the microemulsion with 1% PRE was identified as the most suitable oral spray formulation for oral ulcer treatment.

Microemulsions and nanoemulsions modified with cationic surfactants for improving the solubility and therapeutic efficacy of loaded drug indomethacin

In this work, a noncovalent strategy was successfully used to modify colloidal stability andin vitroandin vivoefficacy of two amphiphilic formulations of the anti-inflammatory drug indomethacin. Namely, nanoemulsions and microemulsions based on oleic acid and nonionic surfactants have been produced and compared. The influence of cationic surfactants cetyltrimethylammonium bromide and its carbamate bearing analogue on the size characteristics, stability and ability to provide prolonged action of loaded drug indomethacin has been evaluated. Adding the positively charged molecules in the surface layer of nanoemulsions and microemulsions has shown the stability increase along with maintaining the size characteristics and homogeneity in time. Moreover, the carbamate modified analogue demonstrated beneficial behavior. Indomethacin loaded in microemulsions and nanoemulsions showed prolonged-release (10%-15% release for 5 h) compared to a free drug (complete release for 5 h). The rate of release of indomethacin from nanoemulsions was slightly higher than from microemulsions and insignificantly decreased with an increase in the concentration of the cationic surfactant. For carbamate surfactant nanocarrier loaded with fluorescence probe Nile Red, the ability to penetrate into the cell was supported by flow cytometry study and visualized by fluorescence microscopy.In vitrotests on anti-inflammatory activity of the systems demonstrated that the blood cell membrane stabilization increased in the case of modified microemulsion. The anti-inflammatory activity of the encapsulated drug was tested in rats using a carrageenan-induced edema model. Nanoemulsions without cationic surfactants appeared more efficient compared to microemulsions. Indomethacin emulsion formulations with carbamate surfactant added showed slower carrageenan-induced edema progression compared to unmodified compositions. Meanwhile, the edema completely disappeared upon treatment with emulsion loaded indomethacin after 4 h in the case of microemulsions versus 5 h in the case of nanoemulsions.

Fabrication, optimisation and evaluation of cisplatin-loaded nanostructured carriers for improved urothelium permeability for intravesical administration

AIM

To design microemulsions as carriers to improve cisplatin permeation capability for intravesical administration.

METHOD

The response surface methodology with factorial design was used to investigate and optimise the influence of the compositions e.g. capryol 90 and 5-pentanediol/transcutol mixture on the permeation accumulation amount and tissue deposition amount of cisplatin-loaded microemulsions. The in vitro permeation study and in vivo intravesical test were conducted to prove the effect of microemulsions.

RESULTS

The droplet size and the viscosity of all drug-loaded formulations ranged 235.8-309.3 nm and 550.8-861.7 cps, respectively. The permeation accumulation amounts significantly increased about 26-fold, by used microemulsion as carriers. In vivo study, the cisplatin deposition amount in bladder tissue significantly increased 4.1-fold (p < 0.05) and the penetration depth increased from 60 μm up 120 μm. The nanocarrier showed considerable thermodynamic stability.

CONCLUSION

The designed nanocarrier was considered to be a promising delivery system for cisplatin intravesical administration.

Dexibuprofen Therapeutic Advances: Prodrugs and Nanotechnological Formulations

S-(+) enantiomer of ibuprofen (IBU) dexibuprofen (DXI) is known to be more potent than its R-(−) form and exhibits many advantages over the racemic mixture of IBU such as lower toxicity, greater clinical efficacy, and lesser variability in therapeutic effects. Moreover, DXI potential has been recently advocated to reduce cancer development and prevent the development of neurodegenerative diseases in addition to its anti-inflammatory properties. During the last decade, many attempts have been made to design novel formulations of DXI aimed at increasing its therapeutic benefits and minimizing the adverse effects. Therefore, this article summarizes pharmacological information about DXI, its pharmacokinetics, safety, and therapeutic outcomes. Moreover, modified DXI drug delivery approaches are extensively discussed. Recent studies of DXI prodrugs and novel DXI nanoformulations are analyzed as well as reviewing their efficacy for ocular, skin, and oral applications.

Lornoxicam controlled release transdermal gel patch: Design, characterization and optimization using co-solvents as penetration enhancers

The aim of the current study was to develop membrane-based transdermal patches of lornoxicam gel using oleic acid (OA)and propylene glycol (PG) as penetration enhancers to improve drug delivery across the skin and to evaluate in vivo analgesic and anti-inflammatory activity. For this purpose, nine formulations were developed in accordance with 32 factorial design using Design Expert® 11. The concentration of propylene glycol (X1) and oleic acid (X2) were selected as independent variable whereas Q10 (Y1), flux (Y2) and lag time (Y3) were considered as the response variables. The impact of drug loading, surface area, gel concentration, membrane variation and agitation speed on drug release and permeation was also studied. The skin sensitivity reaction, analgesic activity and anti-inflammatory action of the optimized patch were also determined in Albino Wistar rats. Stability studies were performed for three months at three different temperature conditions. The result suggests that a membrane-based system with controlled zero-order drug release of 95.8 ± 1.121% for 10 h exhibiting flux of 126.51±1.19 μg/cm2/h and lag time of 0.908 ±0.57h was optimized with the desired analgesic and anti-inflammatory effect can be obtained by using propylene glycol and oleic acid co-solvents as a penetration enhancer. The patch was also found stable at 4˚C for a period of 6.44 months. Formulation F9 comprising of 10% PG and 3% OA was selected as an optimized formulation. The study demonstrates that the fabricated transdermal system of lornoxicam can deliver the drug through the skin in a controlled manner with desired analgesic and anti-inflammatory activity and can be considered as a suitable alternative of the oral route.

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.

Effect of hydrophilic and hydrophobic polymers on permeation of S-amlodipine besylate through intercalated polymeric transdermal matrix: 3(2) designing, optimization and characterization

OBJECTIVE

Innovation in material science has made it possible to fabricate a pharmaceutical material of modifiable characteristics and utility, in delivering therapeutics at a sustained/controlled rate. The objective of this study is to design and optimize the controlled release transdermal films of S-Amlodipine besylate by intercalating hydrophilic and hydrophobic polymers.

METHODS

3(2) factorial design and response surface methodology was utilized to prepare formulations by intercalating the varied concentration of polymers(A) and penetration enhancer(B) in solvent. The effect of these independent factors on drug release and flux was investigated to substantiate the ex-vivo, stability and histological findings of the study.

RESULTS

FTIR, DSC revealed the compatibility of drug with polymers; however, the semicrystallinity in drug was observed under PXRD. SEM micrographs showed homogeneous dispersion and entanglement of drug throughout the matrix. Results from the permeation study suggested the significant effect of factors on the ex vivo permeation of drug. It was observed that drug release was found to be increased with an increase in hydrophilic polymer concentration and PE. The formulations having polymers (EC:PVPK-30) at 7:3 showed maximum drug release with highest flux (102.60 ± 1.12 µg/cm²/h) and permeability coefficient (32.78 ± 1.38 cm/h). Significant effect of PE on lipid and protein framework of the skin was also observed which is responsible for increased permeation. The optimized formulation was found to be stable and showed no-sign of localized reactions, indicating safety and compatibility with the skin.

CONCLUSION

Thus, results indicated that the prepared intercalated transdermal matrix can be a promising nonoral carrier to deliver effective amounts of drug.

Biomedical applications of microemulsion through dermal and transdermal route

Microemulsions are thermodynamically stable, transparent, colloidal drug carrier system extensively used by the scientists for effective drug delivery across the skin. It is a spontaneous isotropic mixture of lipophilic and hydrophilic substances stabilized by suitable surfactant and co-surfactant. The easy fabrication, long-term stability, enhanced solubilization, biocompatibility, skin-friendly appearance and affinity for both the hydrophilic and lipophilic drug substances make it superior for skin drug delivery over the other carrier systems. The topical administration of most of the active compounds is impaired by limited skin permeability due to the presence of skin barriers. In this sequence, the microemulsion represents a cost-effective and convenient drug carrier system which successfully delivers the drug to and across the skin. In the present review work, we compiled various attempts made in last 20 years, utilizing the microemulsion for dermal and transdermal delivery of various drugs. The review emphasizes the potency of microemulsion for topical and transdermal drug delivery and its effect on drug permeability.