Delivery of ibuprofen to the skin

Evaluation of Emulgel and Nanostructured Lipid Carrier-Based Gel Formulations for Transdermal Administration of Ibuprofen: Characterization, Mechanical Properties, and Ex-Vivo Skin Permeation

In transdermal applications of nonsteroidal anti-inflammatory drugs, the rheological and mechanical properties of the dosage form affect the performance of the drug. The aim of this study to develop emulgel and nanostructured lipid carrier NLC-based gel formulations containing ibuprofen, evaluate their mechanical properties, bioadhesive value and ex-vivo rabbit skin permeability. All formulations showed non-Newtonian pseudoplastic behavior and their viscosity values are suitable for topical application. The particle size of the nanostructured lipid carrier system was found to be 468 ± 21 nm, and the encapsulation efficiency was 95.58 ± 0.41%. According to the index of viscosity, consistency, firmness, and cohesiveness values obtained as a result of the back extrusion study, E2 formulation was found to be more suitable for transdermal application. The firmness and work of shear values of the E2 formulation, which has the highest viscosity value, were also found to be the highest and it was chosen as the most suitable formulation in terms of the spreadability test. The work of bioadhesion values of NLC-based gel and IBU-loaded NLC-based gel were found as 0.226 ± 0.028 and 0.181 ± 0.006 mJ/cm2 respectively. The percentages of IBU that penetrated through rabbit skin from the Ibuactive-Cream and the E2 were 87.4 ± 2.11% and 93.4 ± 2.72% after 24 h, respectively. When the penetration of ibuprofen through the skin was evaluated, it was found that the E2 formulation increased penetration due to its lipid and nanoparticle structure. As a result of these findings, it can be said that the NLC-based gel formulation will increase the therapeutic efficacy and will be a good alternative transdermal formulation.

Confocal Raman Spectroscopy for Assessing Bioequivalence of Topical Formulations

The evaluation of bioequivalence (BE) for topical dermatological drug products is challenging, and there has been significant interest from regulatory authorities in developing new BE methodologies in recent years. Currently, BE is demonstrated by comparative clinical endpoint studies; these are costly and time-consuming and often lack sensitivity and reproducibility. Previously, we reported excellent correlations between in vivo Confocal Raman Spectroscopy in human subjects and in vitro skin permeation testing (IVPT) with the human epidermis for skin delivery of ibuprofen and a number of excipients. The aim of the present proof-of-concept study was to evaluate CRS as a method to assess BE of topical products. Two commercially available formulations, Nurofen Max Strength 10% Gel and Ibuleve Speed Relief Max Strength 10% Gel, were selected for evaluation. Delivery of ibuprofen (IBU) to the skin was determined in vitro and in vivo by IVPT and CRS, respectively. The formulations examined were found to deliver comparable amounts of IBU across the skin over 24 h in vitro (p > 0.05). Additionally, the formulations resulted in similar skin uptake values measured with CRS in vivo, either at 1 h or 2 h after application (p > 0.05). This is the first study to report the capability of CRS for the demonstration of BE of dermal products. Future studies will focus on the standardisation of the CRS methodology for a robust and reproducible pharmacokinetic (PK)-based evaluation of topical BE.

Liposome and microemulsion loaded with ibuprofen: from preparation to mechanism of drug transport

To compare the difference between liposome (LP) and microemulsion (ME) in delivering ibuprofen (IBU) transdermally and explore relative mechanism. IBU-LP and IBU-ME were prepared by ethanol injection and spontaneous emulsification, respectively. The percutaneous delivery was evaluated using Franz diffusion cells. Fourier transform infra-red spectroscopy (FTIR), differential scanning calorimetry (DSC), activation energy (Ea), and confocal laser scanning microscopy (CLSM) were used to investigate the transdermal mechanism. The particle size and encapsulation efficiency were 228.00 ± 8.60 nm, 86.68 ± 1.43%(w/w) for IBU-LP, and 56.74 ± 7.11 nm, 91.08 ± 3.27%(w/w) for IBU-ME. Percutaneous study showed that formulations enhanced permeation and drug retention in the skin. FTIR and DSC showed that the permeation occurred due to the interaction of the formulations with the lipid bilayer and the protein. The decrease in Ea (1.506 and 0.939 kcal/mol) revealed that the stratum corneum (SC) lipid bilayers were significantly disrupted and this destructive effect of IBU-LP was stronger. IBU-LP was superior to IBU-ME in the aspects of transdermal delivery of IBU.

Preparation, in vitro and in vivo Evaluation of Thermosensitive in situ Gel Loaded with Ibuprofen-Solid Lipid Nanoparticles for Rectal Delivery

Background

Ibuprofen (IBU), a nonsteroidal anti-inflammatory drug, shows poor gastrointestinal absorption due to its low solubility, which limits its clinical application.

Objective

In the present study, we aimed to develop thermosensitive gel-mediated ibuprofen-solid lipid nanoparticles (IBU-SLN-ISG) to improve the dissolution and bioavailability of IBU after rectal delivery.

Methods

IBU-loaded SLNs (IBU-SLNs) were developed and optimized applying Box-Behnken design. The optimized IBU-SLNs were characterized by physicochemical parameters and morphology. Then, the optimized IBU-SLNs was incorporated into the gel and characterized for gel properties and rheology and investigated its release in vitro, pharmacokinetics in vivo, rectal irritation and rectal retention time.

Results

The optimized SLNs had an EE of 90.74 ± 1.40%, DL of 11.36 ± 1.20%, MPS of 166.77 ± 2.26 nm, PDI of 0.27 ± 0.08, and ZP of −21.00 ± 0.59 mV. The FTIR spectra confirmed successful encapsulation of the drug inside the nanoparticle as only peaks responsible for the lipid could be identified. This corroborated well with XRD spectra, which showed a completely amorphous state of the IBU-SLNs as compared to the crystalline nature of the pure drug. The gelation temperature of the prepared IBU-SLN-ISG was 33.30 ± 0.78°C, the gelation time was 14.67 ± 2.52 s, the gel strength was 54.00 ± 1.41 s, and the mucoadhesion was (11.54±0.37) × 10²dyne/cm². The in vitro results of IBU-SLNs and IBU-SLN-ISG showed a biphasic release pattern with initial burst release followed by sustained release. More importantly, IBU-SLN-ISG produced much better absorption of IBU and improved bioavailability in rats. In addition, IBU-SLN-ISG caused no irritation or damage to rectal tissues, and could be retained in the rectum for a long time.

Conclusion

Thermosensitive in situ gel loaded with IBU-solid lipid nanoparticles might be further developed as a more convenient and effective rectal dosage form.

Comparative Study of Polysaccharide-Based Hydrogels: Rheological and Texture Properties and Ibuprofen Release

Polysaccharides are attractive gelling agents in pharmacy due to their safety, biocompatibility, biodegradability, relatively easy way of preparation, and low price. Due to their variable physical-chemical properties, polysaccharides have potentialities to be used for designing new drug delivery systems for controlled drug release. In this comparative study, rheological and texture properties as well as the in vitro release of model drug ibuprofen (IBU) with 11 polysaccharide-based hydrogels were investigated. The in vitro release of IBU significantly differed between (i) neutral (hydroxy/alkylcelluloses), (ii) anionic (carboxyalkylcellulose and its sodium salt, tragacanth, carrageenan, xanthan gum), and (iii) cationic (chitosans) hydrogels due to different contribution of provided interactions and viscosity within the hydrogel groups. The drug release kinetics of each hydrogel system was evaluated for five kinetic models. Several combinations of cationic hydrogels with neutral or anionic ones were performed to illustrate possibilities of providing modified IBU release profiles. In this context, chitosan was presented as an effective modifier of diffusion profiles for negatively charged drugs formulated into combined polymeric systems, providing their prolonged release. The most appropriate hydrogel for the topical application (i.e., providing favorable rheological and texture properties along with the highest drug release) was selected from a studied series of polysaccharide-based hydrogels.

[Conservative treatment options for arthritis of the ankle : What is possible, what is effective?]

In this article the causes of arthritis in the region of the ankle are introduced and the conservative treatment options are described and discussed more extensively. The risks of treatment with nonopioid analgesics (NOPA) are presented in detail. The topical use of nonsteroidal anti-inflammatory drugs (NSAID) should always be considered in the clinical routine. If contraindications for oral NSAIDs are present, intra-articular treatment is a meaningful option. The best evidence is currently available for viscosupplementation but the study situation for the use of platelet-rich plasma (PRP) is still not sufficiently comprehensive and there are only a few case reports on the use of mesenchymal stem cells..

Modified Single-Walled Carbon Nanotube Membranes for the Elimination of Antibiotics from Water

The hydrophilic and hydrophobic single-walled carbon nanotube membranes were prepared and progressively applied in sorption, filtration, and pertraction experiments with the aim of eliminating three antibiotics—tetracycline, sulfamethoxazole, and trimethoprim—as a single pollutant or as a mixture. The addition of SiO₂ to the single-walled carbon nanotubes allowed a transparent study of the influence of porosity on the separation processes. The mild oxidation, increasing hydrophilicity, and reactivity of the single-walled carbon nanotube membranes with the pollutants were suitable for the filtration and sorption process, while non-oxidized materials with a hydrophobic layer were more appropriate for pertraction. The total pore volume increased with an increasing amount of SiO₂ (from 743 to 1218 mm³/g) in the hydrophilic membranes. The hydrophobic layer completely covered the carbon nanotubes and SiO₂ nanoparticles and provided significantly different membrane surface interactions with the antibiotics. Single-walled carbon nanotubes adsorbed the initial amount of antibiotics in less than 5 h. A time of 2.3 s was sufficient for the filtration of 98.8% of sulfamethoxazole, 95.5% of trimethoprim, and 87.0% of tetracycline. The thicker membranes demonstrate a higher adsorption capacity. However, the pertraction was slower than filtration, leading to total elimination of antibiotics (e.g., 3 days for tetracycline). The diffusion coefficient of the antibiotics varies between 0.7–2.7 × 10⁻¹⁰, depending on the addition of SiO₂ in perfect agreement with the findings of the textural analysis and scanning electron microscopy observations. Similar to filtration, tetracycline is retained by the membranes more than sulfamethoxazole and trimethoprim.

Enhancement of Skin Delivery of Drugs Using Proposome Depends on Drug Lipophilicity

The study aims to investigate the propylene glycol-based liposomes named 'proposomes' in enhancing skin permeation of drugs with different physicochemical properties. Ibuprofen, tofacitinib citrate, rhodamine B, and lidocaine were loaded into proposomes. These drug formulations were analyzed for particle size, zeta potential, polydispersity index, entrapment efficiency, and in vitro skin permeation. The confocal laser scanning microscopy was performed on skin treated with calcein and rhodamine B laden proposomes. The transdermal delivery relative to physicochemical properties of drugs such as logP, melting point, molecular weight, solubility, etc., were analyzed. We tested the safety of the proposomes using reconstructed human skin tissue equivalents, which were fabricated in-house. We also used human cadaver skin samples as a control. The proposomes had an average diameter of 128 to 148 nm. The drug's entrapment efficiencies were in the range of 42.9-52.7%, translating into the significant enhancement of drug permeation through the skin. The enhancement ratio was 1.4 to 4.0, and linearly correlated to logP, molecular weight, and melting point. Confocal imaging also showed higher skin permeation of calcein and rhodamine B in proposome than in solution. The proposome was found safe for skin application. The enhancement of skin delivery of drugs through proposomes was dependent on the lipophilicity of the drug. The entrapment efficiency was positively correlated with logP of the drug, which led to high drug absorption.

Transdermal Delivery Systems for Ibuprofen and Ibuprofen Modified with Amino Acids Alkyl Esters Based on Bacterial Cellulose

The potential of bacterial cellulose as a carrier for the transport of ibuprofen (a typical example of non-steroidal anti-inflammatory drugs) through the skin was investigated. Ibuprofen and its amino acid ester salts-loaded BC membranes were prepared through a simple methodology and characterized in terms of structure and morphology. Two salts of amino acid isopropyl esters were used in the research, namely L-valine isopropyl ester ibuprofenate ([ValOiPr][IBU]) and L-leucine isopropyl ester ibuprofenate ([LeuOiPr][IBU]). [LeuOiPr][IBU] is a new compound; therefore, it has been fully characterized and its identity confirmed. For all membranes obtained the surface morphology, tensile mechanical properties, active compound dissolution assays, and permeation and skin accumulation studies of API (active pharmaceutical ingredient) were determined. The obtained membranes were very homogeneous. In vitro diffusion studies with Franz cells were conducted using pig epidermal membranes, and showed that the incorporation of ibuprofen in BC membranes provided lower permeation rates to those obtained with amino acids ester salts of ibuprofen. This release profile together with the ease of application and the simple preparation and assembly of the drug-loaded membranes indicates the enormous potentialities of using BC membranes for transdermal application of ibuprofen in the form of amino acid ester salts.

In Vitro-In Vivo Correlation in Dermal Delivery: The Role of Excipients

The composition of topical and transdermal formulations is known to determine the rate and the extent of drug delivery to and through the skin. However, to date, the role of excipients in these formulations on skin delivery of actives has received little attention from scientists in the field. Monitoring skin absorption of both drug and vehicle may provide insights into the mechanism by which excipients promote permeation and may facilitate the design of effective and safer products. Previously, we have investigated the use of quantitative Confocal Raman Spectroscopy (CRS) to investigate the delivery of an active to the skin, and we also reported the first fully quantitative study that compared this method with the well-established in vitro permeation test (IVPT) model. To further explore the potential of quantitative CRS in assessing topical delivery, the present work investigated the effects of commonly used excipients on the percutaneous absorption of a model drug, ibuprofen (IBU). Permeation of IBU and selected solvents following finite dose applications to human skin was determined in vitro and in vivo by Franz diffusion studies and quantitative CRS, respectively. The solvents used were propylene glycol (PG), dipropylene glycol (DPG), tripropylene glycol (TPG), and polyethylene glycol 300 (PEG 300). Overall, the cumulative amounts of IBU that permeated at 24 h in vitro were similar for PG, DPG, and TPG (p > 0.05). These three vehicles outperformed PEG 300 (p < 0.05) in terms of drug delivery. Concerning the vehicles, the rank order for in vitro skin permeation was DPG ≥ PG > TPG, while PEG 300 did not permeate the skin. A linear relationship between maximum vehicle and IBU flux in vitro was found, with a correlation coefficient (R²) of 0.95. When comparing in vitro with in vivo data, a positive in vitro–in vivo (IVIV) correlation between the cumulative permeation of IBU in vitro and the total amount of IBU that penetrated the stratum corneum (SC) in vivo was observed, with a Pearson correlation coefficient (R²) of 0.90. A strong IVIV correlation, R² = 0.82, was found following the linear regression of the cumulative number of solvents permeated in vitro and the corresponding skin uptake in vivo measured with CRS. This is the first study to correlate in vivo permeation of solvents measured by CRS with data obtained by in vitro diffusion studies. The IVIV correlations suggest that CRS is a powerful tool for profiling drug and vehicle delivery from dermal formulations. Future studies will examine additional excipients with varying physicochemical properties. Ultimately, these findings are expected to lead to new approaches for the design, evaluation, and optimization of formulations that target actives to and through the skin.

Dense nanolipid fluid dispersions comprising ibuprofen: Single step extrusion process and drug properties

Dense nanolipid fluid (DNLF) dispersions are highly concentrated aqueous dispersions of lipid nanocarriers (LNCs) with more than 10¹⁵ lipid particles per cubic centimeter. Descriptions of dense nanolipid fluid dispersions in the scientific literature are rare, and they have not been used to encapsulate drugs. In this paper we describe the synthesis of DNLF dispersions comprising ibuprofen using a recently described twin-screw extrusion process. We report that such dispersions are stable, bind ibuprofen tightly and yet provide high transdermal drug permeation. Ibuprofen DNLF dispersions prepared according to the present study provide up to five times greater flux of the pharmacologically active S-ibuprofen isomer through human skin than a commercially available racemic ibuprofen emulsion product. We demonstrate scaling up the twin-screw extrusion method to pilot production for a stable, highly permeating ibuprofen DNLF composition based on excipients approved by the US FDA for use in topical products as a key step towards development of a commercially viable, FDA approvable topical ibuprofen medicine to treat osteoarthritis, which has never before been accomplished.

Hydrogel-assisted delivery of lipophilic molecules into aqueous medium for transdermal medication based on environment-specific, regioselective adsorption of graphene oxides

Graphene oxide (GO)-laden agarose composite hydrogels (GOACHs) were utilized to deliver lipophilic molecules from organic to aqueous media without alteration of the lipophilic nature of the molecules and the hydrophilic nature of the GOACHs. After the agarose host networks of the GOACHs were impregnated with the non-polar organic solution of lipophilic molecules via stepwise solvent exchange, their GO guests wielded the edge polar groups to effectively adsorb the lipophilic molecules via hydrogen bonding. After being transferred to aqueous media, the GOACHs were able to not only release the loaded lipophilic molecules but also to adsorb the released lipophilic molecules on the GO non-polar carbon lattice planes via hydrophobic interactions, thus resulting in deliberately balanced release of lipophilic molecules in aqueous media. Based on this environment-specific, regioselective adsorption of their GO guests, the GOACHs were harnessed as carriers for sustained delivery of ibuprofen across rat skin, underpinning their applicability in transdermal medication.

The effect of alcohols as vehicles on the percutaneous absorption and skin retention of ibuprofen modified with l-valine alkyl esters

The effect of various alcohols as vehicles on skin permeability was compared for unmodified ibuprofen (IBU) and ion pairs of ibuprofen with l-valine alkyl esters [ValOR][IBU], in which the alkyl chain R was changed from C1 to C8. In vitro permeation experiments were conducted in a Franz cell with porcine skin. Methanol, ethanol, and isopropanol solutions of 70% (v/v) were chosen as vehicles for penetrants and a buffer solution of pH 5.4 or 7.4 as the acceptor phase. The comparisons of permeation profiles for various [ValOR][IBU] from different alcohols were determined. The cumulative mass, skin accumulation, steady-state flux, diffusion coefficient, and lag time were investigated and compared. It was observed that i-propanol was the best enhancer of skin permeation of both unmodified ibuprofen and its salts with l-valine alkyl esters for both acceptor phases. The permeability of the various carriers increases with increasing chain-length of the alcohol. In most cases, significantly higher cumulative mass was found in the acceptor buffer of pH 7.4. The conjugate of ibuprofen with l-valine propyl ester [ValOPr][IBU] permeated the skin to the highest degree in comparison to unmodified ibuprofen. The accumulation of ibuprofen was higher for all salts in relation to the parent acid applied onto the skin. The greatest amounts of ibuprofen were accumulated in the skin when ibuprofen was used as the ionic pair with l-valine butyl ester, [ValOBu][IBU] in the i-propanol solution and pH 7.4 buffer as the acceptor phase.

The effect of various alcohols as vehicles on skin permeability was compared for unmodified ibuprofen (IBU) and ion pairs of ibuprofen with l-valine alkyl esters [ValOR][IBU], in which the alkyl chain R was changed from C1 to C8.

Ibuprofen gargle for chemo- or Chemoradiotherapy-induced Oral Mucositis: a feasibility study

Background

Oral mucositis frequently occurs in cancer patients treated with chemotherapy and chemoradiotherapy (CRT). This study examined the safety and efficacy of ibuprofen gargle in healthy volunteers and patients with chemotherapy- and concomitant CRT-induced oral mucositis.

Methods

We enrolled healthy volunteers and patients with chemotherapy- and CRT-induced oral mucositis. In cohort I, single and multiple doses of ibuprofen gargle (0.6% or 1.0%) were administered to healthy volunteers on day 1 and days 4–10. In cohort II, multiple doses of ibuprofen gargle (0.6%) were administered to patients with complicated grade 2–3 oral mucositis based on the Common Terminology Criteria for Adverse Events (CTCAE) version 4.0. The primary endpoint of cohort I was the treatment-related adverse events (TRAEs) as defined by CTCAE version 4.0. The primary endpoint of cohort II was the change in the visual analogue scale (VAS) pain score from before to 15 min after gargle use on day 3. The incidence and severity of TRAEs were assessed based on the CTCAE version 4.0 and a subjective rating scale completed by healthy volunteers and patients.

Results

In cohort I, 9 of 10 healthy volunteers were evaluable for safety. All 9 healthy volunteers reported the TRAE of oral irritation with single or multiple use of the gargle. In cohort II, 10 patients were enrolled and evaluable for safety and 7 of 10 patients were evaluable for efficacy. The mean change in the VAS pain score from before to 15 min after using the gargle on day 3 was − 1.28 (95% confidence interval: − 2.06, − 0.51), and all patients experienced some degree of pain relief (range: − 0.2 to − 2.5). All 10 patients reported the TRAE of oral irritation. No other TRAEs of ibuprofen gargle were observed in the healthy volunteers and patients.

Conclusion

Despite oral irritation, the ibuprofen gargle appeared to be safe and effective for the pain related to chemo- or CRT-induced oral mucositis. However, ibuprofen-related oral irritation warrants further formulation improvement.

Trial registration

This study was registered with the University Hospital Medical Information Network Clinical Trials Registry (UMIN000014433).

Ex Vivo Permeation of Carprofen Vehiculated by PLGA Nanoparticles through Porcine Mucous Membranes and Ophthalmic Tissues

(1) Background: Carprofen (CP), 2-(6-chlorocarbazole) propionic acid, is used as an anti-inflammatory, analgesic and anti-pyretic agent and it belongs to the family of non-steroidal anti-inflammatory drugs (NSAIDs). CP has some adverse reactions in systemic administration; for this reason, topical administration with CP nanoparticles (CP-NPs) can be an optimal alternative. The main objective of this work is the investigation of ex vivo permeation of CP through different types of porcine mucous membranes (buccal, sublingual and vaginal) and ophthalmic tissues (cornea, sclera and conjunctiva) to compare the influence of CP-NPs formulation over a CP solution (CP-Solution). (2) Methods: The ex vivo permeation profiles were evaluated using Franz diffusion cells. Furthermore, in vivo studies were performed to verify that the formulations did not affect the cell structure and to establish the amount retained (Qr) in the tissues. (3) Results: Permeation of CP-NPs is more effective in terms of drug retention in almost all tissues (with the exception of sclera and sublingual). In vivo studies show that neither of the two formulations affects tissue structure, so both formulations are safe. (4) Conclusions: It was concluded that CP-NPs may be a useful tool for the topical treatment of local inflammation in veterinary and human medicine.

Transdermal Administration of Ibuprofen-Loaded Gel: Preparation, Pharmacokinetic Profile, and Tissue Distribution

The purpose of this study was to compare the pharmacokinetics and tissue distribution of ibuprofen (IBU) gel in female rats after transdermal administration through the skin of the abdomen and back. IBU was used as the model drug to prepare carbomer gel. After the abdominal and back administration, the concentration of IBU in rat plasma was detected by high-performance liquid chromatography (HPLC). Besides, the contents of IBU in the uterus, heart, liver, spleen, lung, and kidney were detected, respectively, to clarify the distribution characteristics in vivo. Through abdominal route, the AUC0- ∞ (area under the concentration-time curve from time zero to infinity) of uterus was 424.75 μg/g h, which is 3.60 times higher than that of plasma, and was significantly higher than that of other tissues (P < 0.0001). Tmax (peak time) of uterus and plasma was 4 h and 2 h, respectively. Upon transdermal application of IBU to the back, the AUC0-∞ of uterus was 75.47 μg/g h, which is 12.63 times lower than that of plasma, while Tmax of uterus and plasma was not lower than 20 h. These results indicated that IBU entered the blood circulation through abdominal administration in a small amount and mainly of the drug entered the uterus, while IBU entered the blood circulation and redistributed to tissues after absorption through the dorsal skin slowly. IBU could effectively reach the uterus and have a certain targeting through abdominal administration, which provides a prospect for clinical transdermal administration in the treatment of dysmenorrhea.

Enhancement of ibuprofen solubility and skin permeation by conjugation with l-valine alkyl esters

New ibuprofen derivatives were made via conjugation with l-valine alkyl esters (ValOR), where R was changed from an ethyl to a hexyl group. The ionic structure was confirmed using NMR and FTIR. Specific rotation, solubility in commonly used solvents, thermal properties including phase transitions temperatures, and thermal stability were also determined. The ionic structure with a protonated amine group on an l-valine ester and melting points below 100 °C allowed inclusion of these ibuprofen derivatives into the pharmaceutically active protic ionic liquids. The ibuprofen salt solubility in deionised water and two buffer solutions at pH 5.4 and 7.4 were established and compared with the parent acid solubility. The octanol/water (buffer) partition coefficient, permeation through porcine skin, and accumulation in the skin were also measured. Ibuprofen pairing with l-valine alkyl esters [ValOR][IBU], caused higher solubility and a greater drug molecule absorption through biological membranes. log P was lower for ibuprofen salts than for the acid and it increased with a longer l-valine ester cation alkyl chain. In vitro porcine skin tests showed that ibuprofen salts with a propyl or isopropyl ester in l-valine are particularly relevant for topical application. They provide transport for ibuprofen through the skin at much higher rate than the unmodified acid and a higher permeated ibuprofen concentration, which can improve efficacy. Thus, synthesised ibuprofen derivatives could be used as drug carriers in transdermal systems to provide better drug bioavailability, and they can be also be the source of exogenous l-valine.

New ibuprofen derivatives made via conjugation with l-valine alkyl esters have better solubility in aqueous solutions and a lower log P value compared to the parent acid. They provide faster and more completely permeation of drug through the skin.

Long-Lasting, Antinociceptive Effects of pH-Sensitive Niosomes Loaded with Ibuprofen in Acute and Chronic Models of Pain

Ibuprofen is one of the non-steroidal anti-inflammatory drugs (NSAIDs) widely used to treat pain conditions. NSAIDs encounter several obstacles to passing across biological membranes. To overcome these constraints, we decided to study the effects of a new pH-sensitive formulation of niosomes containing Polysorbate 20 derivatized by Glycine and loaded with ibuprofen (NioIbu) in several animal models of pain in mice. We performed two tests commonly used to study acute antinociceptive activity, namely the writhing test and the capsaicin test. Our results demonstrated that NioIbu, administered 2 h before testing, reduced nociception, whereas the free form of ibuprofen was ineffective. In a model of inflammatory pain, hyperalgesia induced by zymosan, NioIbu induced a long-lasting reduction in hyperalgesia in treated mice. In a model of neuropathic pain induced by sciatic nerve chronic constriction, NioIbu reduced both neuropathy-induced allodynia and hyperalgesia. The results obtained in our experiments suggest that pH-sensitive niosomes containing Polysorbate 20 derivatized by Glycine is an effective model for NSAIDs delivery, providing durable antinociceptive effects and reducing the incidence of side effects.

Cutaneous irritancy of an ibuprofen medicated plaster in healthy volunteers

OBJECTIVES

To assess the irritation and contact sensitization potential of a 200 mg ibuprofen medicated plaster.

METHODS

This double-blind, phase-1 placebo controlled study had two phases; the induction phase to evaluate the irritant potential of continuous application of the plaster, and the challenge phase to assess contact sensitivity (allergy). The cumulative irritancy potential was evaluated using an adaptation of the Shelanski method. Healthy adults (≥18 years of age) (N = 210) were treated simultaneously with one ibuprofen medicated and one placebo plaster applied in a randomized fashion to either the left or right side of the lower back. During the induction phase, plasters were applied on Days 1, 3, 5, 8, 10, 12, 15, 17, and 19 and the final plaster removed on Day 22. At each scheduled visit plasters and applications sites were assessed for degree of adhesion and skin irritation (score of 1 = no irritation to 7 = strong reaction spreading beyond test sites), respectively. The challenge phase followed a two-week washout period. A plaster was applied on Day 36 for 48 h and assessment occurred on Days 38, 39, and 40.

RESULTS

The mean cumulative irritation score during the induction phase was lower for the ibuprofen medicated plaster than the placebo plaster (0.32 vs. 1.23, respectively). Three (1.4%) subjects experience a dermal reaction of grade ≥3 for the ibuprofen medicated plaster compared with 27 (12.7%) for the placebo plaster. Following challenge with ibuprofen or placebo plasters, 12 subjects (6.2%) with the ibuprofen medicated plaster and four (2.2%) with the placebo plaster had skin reaction of assessment grade higher than the induction phase. One subject for the ibuprofen and two for the placebo plaster had reactions with grade >2. No subjects showed an increase in sensitization on Day 39 or 40 compared with Day 38.

CONCLUSIONS

The findings indicate that the both the irritancy and contact sensitization of the ibuprofen medicated plaster is acceptable.

A Pharmacokinetic Study of an Ibuprofen Topical Patch in Healthy Male and Female Adult Volunteers

The pharmacokinetics of a novel locally applied ibuprofen topical patch was evaluated. Healthy subjects (n = 28) were administered a 200-mg ibuprofen patch every 24 hours for 5 days, and steady-state pharmacokinetics was determined. The amount of ibuprofen remaining in the patch following each patch removal was also assessed. The maximum steady-state drug concentration and area under the concentration curve from time 0 on day 5 (t = 0) to the 24-hours sample on day 6 were 514 ng/mL (95% CI 439 to 603 ng/mL) and 9.78 kg·h/mL (95% CI 8.43 to 11.4 kg·h/mL), respectively. Maximum ibuprofen concentration on day 5 occurred at 20 hours post-patch application. No evidence of drug accumulation was observed, and steady state was achieved between days 2 and 5. Ibuprofen levels attenuated rapidly to baseline within 24 hours after treatment discontinuation. The amount of ibuprofen remaining in the patch was high (≥80%). Treatment-emergent adverse events were generally mild, with the most prevalent being headache (n = 6; 21.4%). Only 4 TEAEs were considered related to the ibuprofen patch: paresthesia (n = 1), headache (n = 2), and pruritic rash (n = 1). The study found that the systematic absorption of ibuprofen from a 200-mg patch was low and that the levels of ibuprofen leaving the patch over a 24-hour period are consistent with levels required for therapeutic relief as shown in other studies.

Efficacy and tolerability of a new ibuprofen 200mg plaster in patients with acute sports-related traumatic blunt soft tissue injury/contusion

BACKGROUND

Ibuprofen is used for the treatment of non-serious pain. This study assessed the efficacy and safety of a new ibuprofen plaster for the treatment of pain associated with acute sports impact injuries/contusions.

METHODS

In this randomised, double-blind, multi-centre, placebo controlled, parallel group study, adults (n = 130; 18-58 years of age) diagnosed with acute sports-related blunt soft tissue injury/contusion were randomized to receive either ibuprofen 200 mg plaster or placebo plaster. Plasters were administered once daily for five consecutive days. The primary assessment was area under the visual analogue scale (VAS) of pain on movement (POM) over 0 to three days (VAS AUC_0-3d). Other endpoints included algometry AUC from 0 to three days (AUC_0-3d) and 0 to five days (AUC_0-5d), to evaluate improvement of sensitivity at the injured site, and patient and investigator global assessment of efficacy. Safety was monitored throughout the study.

RESULTS

The ibuprofen plaster resulted in superior reduction in AUC_0-3d compared with placebo; the Least Squares (LS) mean difference was 662.82 mm*h in favour of the ibuprofen 200mg plaster (P = 0.0011). The greater improvement in VAS AUC of POM was also observed after 12 h, 24 h, and five days of therapy. Tenderness also significantly improved with the ibuprofen plaster compared with placebo; LS mean difference in algometry/tenderness AUC_0-3d was 1.87 N/cm²*d and AUC_0-5d was 1.87 N/cm²*d (P values ≤0.0004). At all study timepoints, a greater percentage of patients and investigators rated the effectiveness of the ibuprofen 200 mg plaster as good/excellent than the placebo plaster. Treatment-emergent adverse events for the ibuprofen plaster were few (≤1.5%) and were mild in severity.

CONCLUSIONS

The results of this study indicate 200 mg plaster is effective and safe for the treatment of pain due to acute sports-related traumatic blunt soft tissue injury/contusion in adults.

Efficacy and safety assessment of acute sports-related traumatic soft tissue injuries using a new ibuprofen medicated plaster: results from a randomized controlled clinical trial

OBJECTIVE

To investigate the efficacy and safety of a recently developed ibuprofen medicated plaster in the treatment of acute sports impact injuries/contusions.

METHODS

In this double-blind, multi-center, placebo-controlled, parallel group, phase 3 study (EudraCT Number: 2012-003257-2) patients (n = 132; ages 18 to 60 years) diagnosed with acute sports-related traumatic blunt soft tissue injury/contusion to the upper or lower limbs were randomized to receive either ibuprofen 200 mg plaster (n = 64) or placebo plaster (n = 68). Plasters were administered once daily for five consecutive days. The primary assessment was the area under the curve (AUC) of the visual analogue scale (VAS) of pain on movement (POM) over 0 to 72 h (VAS_0-72).

RESULTS

The ibuprofen medicated plaster was associated with a reduction in pain on movement (POM) based on lower VAS AUC_0-72h (2399.4 mm*h) compared with placebo (4078.9 mm*h) (least squares mean difference: - 1679.5 mm*h; P < 0.0001). The reduction in AUC of POM was also significantly greater for the ibuprofen medicated plaster compared with placebo at 12, 48, 24, and 120 h (P < 0.0001). Algometry/tenderness measurements found that the ibuprofen medicated plaster was associated with greater reduction in tenderness/pain than placebo at each timepoint (P values <0.0001). Seven patients experienced drug-related adverse events (n = 1 [1.6%] for the ibuprofen plaster, and n = 6 [8.8%] for placebo). All drug-related AEs were administration site reactions and were mild in intensity.

CONCLUSIONS

The results of this study indicate that ibuprofen medicated plaster results in rapid and clinically relevant reduction of pain in patients suffering from blunt musculoskeletal injuries or recurrent pain. The ibuprofen medicated plaster was well tolerated.

Cutaneous irritancy of an ibuprofen medicated plaster in healthy volunteers

OBJECTIVE

Ibuprofen is a commonly used non-steroidal anti-inflammatory drug administered to treat injuries, joint pain, and recurrent muscular skeletal pain. The aim of this study was to determine the cutaneous irritancy of a medicated ibuprofen plaster compared with a placebo plaster in healthy volunteers.

METHODS

Healthy volunteers (N = 31) were treated at the same time with one ibuprofen and one placebo plaster. The ibuprofen and placebo plaster were applied in a randomized fashion to sites on the left or right side of subjects' lower backs. At each scheduled visit, the plasters and applications sites were assessed for degree of adhesion and skin irritancy, respectively. The plasters were applied on study Days 1, 2, 3, 5, 8, 10, 12, 15, 17, and 19, with final plaster removal on Day 22.

RESULTS

The ibuprofen medicated plaster compared with placebo had a lower percentage of Grade 1 (23.3% vs. 46.7%, respectively), Grade 2 (10% vs. 20%), and ≥Grade 3 (3% vs. 16.1%) irritancy scores after 21 days of application. The mean irritation score across the study was 0.40 for the ibuprofen medicated plaster and 1.18 for the placebo plaster. The irritation score on Day 22 of the study was 0.53 for the ibuprofen medicated plaster and 1.50 for placebo. The placebo plaster was associated with a higher number of stopped applications due to Grade 3 or above skin reactions compared with the ibuprofen medicated plaster (5 vs. 1, respectively).

CONCLUSION

The ibuprofen medicated plaster was well tolerated and was associated with lower irritancy than the placebo plaster.

Formulation and delivery strategies of ibuprofen: challenges and opportunities

Ibuprofen, a non-steroidal anti-inflammatory drug (NSAID), is mostly administered orally and topically to relieve acute pain and fever. Due to its mode of action this drug may be useful in the treatment regimens of other, more chronic conditions, like cystic fibrosis. This drug is poorly soluble in aqueous media and thus the rate of dissolution from the currently available solid dosage forms is limited. This leads to poor bioavailability at high doses after oral administration, thereby increasing the risk of unwanted adverse effects. The poor solubility is a problem for developing injectable solution dosage forms. Because of its poor skin permeability, it is difficult to obtain an effective therapeutic concentration from topical preparations. This review aims to give a brief insight into the status of ibuprofen dosage forms and their limitations, particle/crystallization technologies for improving formulation strategies as well as suggesting its incorporation into the pulmonary drug delivery systems for achieving better therapeutic action at low dose.

Development of ibuprofen-loaded nanostructured lipid carrier-based gels: characterization and investigation of in vitro and in vivo penetration through the skin

An ibuprofen-loaded nanostructured lipid carrier (IBU-NLC) was developed for enhanced skin penetration to improve the treatment of osteoarthritis and other musculoskeletal diseases. The mean particle size was 106 nm, with a spherical morphology, a smooth surface, and a zeta potential of -18.4 mV. X-ray diffraction studies revealed the amorphous state of the lipid matrix. Both Raman spectroscopy and Fourier transformation infrared analysis indicated no major shifts in the spectra of the formulations, which suggest rapid drug dissolution from the nanoparticles. The drug loading was 9.85%, and the entrapment efficiency was 98.51%. In vitro release of the NLC dispersion, in vitro permeation, and in vivo animal studies of IBU-NLC gel all confirmed that the permeation of IBU was significantly better than that of a reference after 6 hours. In conclusion, IBU-NLC gel is of great potential to enhance drug permeation through the skin and hence the efficacy of the treatment of chronic joint inflammation.

Ex vivo permeation of carprofen from nanoparticles: A comprehensive study through human, porcine and bovine skin as anti-inflammatory agent

The purpose of this study was the development of poly(d,l-lactide-co-glycolide) acid (PLGA) nanoparticles (NPs) for the dermal delivery of carprofen (CP). The developed nanovehicle was then lyophilized using hydroxypropyl-β-cyclodextrin (HPβCD) as cryoprotectant. The ex vivo permeation profiles were evaluated using Franz diffusion cells using three different types of skin membranes: human, porcine and bovine. Furthermore, biomechanical properties of skin (trans-epidermal water loss and skin hydration) were tested. Finally, the in vivo skin irritation and the anti-inflammatory efficacy were also assayed. Results demonstrated the achievement of NPs 187.32 nm sized with homogeneous distribution, negatively charged surface (-23.39 mV) and high CP entrapment efficiency (75.38%). Permeation studies showed similar diffusion values between human and porcine skins and higher for bovine. No signs of skin irritation were observed in rabbits. Topically applied NPs significantly decreased in vivo inflammation compared to the reference drug in a TPA-induced mouse ear edema model. Thus, it was concluded that NPs containing CP may be a useful tool for the dermal treatment of local inflammation.

Ex vivo skin permeation and retention studies on chitosan-ibuprofen-gellan ternary nanogel prepared by in situ ionic gelation technique--a tool for controlled transdermal delivery of ibuprofen

The chemical potentials of drug-polymer electrostatic interaction have been utilized to develop a novel ternary chitosan-ibuprofen-gellan nanogel as controlled transdermal delivery tool for ibuprofen. The ternary nanogels were prepared by a combination of electrostatic nanoassembly and ionic gelation techniques. The electrostatic and hydrophobic interactions as well as hydrogen bonding between ibuprofen and chitosan were confirmed with FTIR, while DSC, TGA and SEM confirmed the physical state, thermal and morphological characteristics, respectively. The ex vivo delivery of ibuprofen onto and across the skin was evaluated based on system specific drug release parameters such as steady state permeation rate, permeability coefficient, permeability enhancement ratio, skin/gel partition coefficient, diffusion coefficient, lag time and release rate constant and mechanisms of release were determined using mathematical models. Interaction between ibuprofen and chitosan produced new spherical eutectic nanoconjugates with remarkable decrease in particle size of ibuprofen from 4580 (length-to-breadth aspect ratio) to a minimum of 14.15 nm (324-times), and thermally stable amorphous characteristics. The nanogels exhibited significant elastic and pseudoplastic characteristics dictated by the concentration of chitosan with maximum swelling capacity of 775% w/w at 6.55 mM chitosan compared with 281.16 and 506.50% for plain gellan and control ibuprofen hydrogel, respectively. Chitosan enhanced the skin penetration, permeability and the rate of transdermal release of ibuprofen by a factor of 4, dictated by the extent of ibuprofen-chitosan ionic interaction and its concentration. The major mechanism of ibuprofen release through the pig skin was drug diffusion however drug partition and matrix erosion also occurred. It was evident that ternary nanogels are novel formulations with potential application in controlled transdermal delivery of ibuprofen.

Human skin penetration of hyaluronic acid of different molecular weights as probed by Raman spectroscopy

BACKGROUND

Topical delivery of molecules into the human skin is one of the main issues in dermatology and cosmetology. Several techniques were developed to study molecules penetration into the human skin. Although widely accepted, the conventional methods such as Franz diffusion cells are unable to provide the accurate localization of actives in the skin layers. A different approach based on Raman spectroscopy has been proposed to follow-up the permeation of actives. It presents a high molecular specificity to distinguish exogenous molecules from skin constituents.

METHODS

Raman micro-imaging was applied to monitor the skin penetration of hyaluronic acids (HA) of different molecular weights. The first step, was the spectral characterization of these HA. After, we have determined spectral features of HA by which they can be detected in the skin. In the second part, transverse skin sections were realized and spectral images were recorded.

RESULTS

Our results show a difference of skin permeation of the three HA. Indeed, HA with low molecular weight (20-300 kDa) passes through the stratum corneum in contrast of the impermeability of high molecular weight HA (1000-1400 kDa).

CONCLUSION

Raman spectroscopy represents an analytical, non-destructive, and dynamic method to evaluate the permeation of actives in the skin layers.

Transdermal delivery of Angiotensin Converting Enzyme inhibitors

The Angiotensin Converting Enzyme (ACE) inhibitor class of drugs has been in clinical use since the 1970s for the management of all grades of heart failure, hypertension, diabetic nephropathy and prophylaxis of cardiovascular events. Because of the advantages associated with transdermal delivery compared with oral delivery many researchers have investigated the skin as a portal for administration of ACE inhibitors. This review summarises the various studies reported in the literature describing the development and evaluation of transdermal formulations of ACE inhibitors. Captopril, enalapril maleate, lisinopril dihydrate, perindopril erbumine and trandolapril are the most studied in connection with transdermal preparations. The methodologies reported are considered critically and the limitations of the various skin models used are also highlighted. Finally, opportunities for novel transdermal preparations of ACE inhibitor drugs are discussed with an emphasis on rational formulation design.

Fabrication of degradable polymer microspheres via pH-responsive chitosan-based Pickering emulsion photopolymerization

Degradable polymer microspheres were facilely fabricated by chitosan-based Pickering emulsion photopolymerization.