A novel transdermal patch incorporating meloxicam: In vitro and in vivo characterization

Long-Acting Drug Delivery Technologies for Meloxicam as a Pain Medicine

Meloxicam, a selective COX-2 inhibitor, has demonstrated clinical effectiveness in managing inflammation and acute pain. Although available in oral and parenteral formulations such as capsule, tablet, suspension, and solution, frequent administration is necessary to maintain therapeutic efficacy, which can increase adverse effects and patient non-compliance. To address these issues, several sustained drug delivery strategies such as oral, transdermal, transmucosal, injectable, and implantable drug delivery systems have been developed for meloxicam. These sustained drug delivery strategies have the potential to improve the therapeutic efficacy and safety profile of meloxicam, thereby reducing the frequency of dosing and associated gastrointestinal side effects. The choice of drug delivery system will depend on the desired release profile, the target site of inflammation, and the mode of administration. Overall, meloxicam sustained delivery systems offer better patient compliance, and reduce the side effects, thereby improving the clinical applications of this drug. Herein, we discuss in detail different strategies for sustained delivery of meloxicam.

Brønsted acid-promoted ring-opening and annulation of thioamides and 2H-azirines to synthesize 2,4,5-trisubstituted thiazoles

In this study, a metal-free synthesis of 2,4,5-trisubstituted thiazoles using 2H-azirines and thioamides is disclosed. Under the catalysis of HClO₄, the protocol was realized through a novel chemical bond breaking of 2H-azirine, which is usually achieved using a metal catalyst. It provides an efficient and green route for the synthesis of substituted thiazoles with a broad substrate scope. Preliminary mechanistic studies show that such a reaction may involve a ring-opening reaction, annulation, and a hydrogen atom rearrangement process.

Effect of plasticizers on drug-in-adhesive patches containing 5-fluorouracil

Topical patches containing 5-fluorouracil (5-FU) are a feasible alternative to overcome the shortcomings of commercial cream for the treatment of non-melanoma skin cancer (NMSC). Plasticizers are a critical component of drug-in-adhesive (DIA) patches as they can significantly affect the mechanical, adhesive and drug release characteristics of the patches. Eudragit® E (EuE) is a methacrylate-based cationic copolymer capable of producing flexible and adhesive films for topical application. In this study, the effect of plasticizers on the mechanical, adhesive and 5-FU release characteristics of EuE-based patches was comprehensively evaluated. While the elongation at break (%) and adhesion of the films were significantly increased with increasing triacetin, dibutyl sebacate (DBS) and triethyl citrate (TEC) concentrations, the tensile strength showed an inverse relationship. EuE plasticized with 40% triacetin, 30% DBS or 40% w/w TEC produced elastic and adhesive films most suitable for topical application. In vitro release studies of the 5-FU-loaded patches demonstrated an initial burst release pattern during the first 10 min followed by a slow release over 120 min. In summary, this study provides important information on effect of plasticizers for preparation of EuE-based patches with desired mechanical, adhesive and release characteristics of 5-FU towards their potential application in the treatment of NMSC.

[Detection and Analysis of Drug Crystals in Medical Transdermal Patches by Using X-ray Diffraction Measurement]

The crystallization of active pharmaceutical ingredients (APIs) in matrix-type transdermal patches has implications for the rate of drug absorption through the skin and patch adhesion strength. Therefore, the presence or absence and the degree of API crystallinity must be controlled to guarantee the quality of patches. In this study, the utility of laboratory-level X-ray diffractometers for the detection and analysis of crystalline APIs in transdermal patches was investigated using medical patches of tulobuterol and isosorbide dinitrate. Several matrix-type patches employ a controlled drug delivery system containing intentionally crystallized API. Both benchtop and high-resolution laboratory X-ray diffractometers can detect several characteristic peaks of the APIs in these patches even if the patches are wrapped in an outer bag, although a benchtop model provides peak heights one-seventh to one-fifth that of a high-resolution instrument. An isosorbide dinitrate patch containing an unintentionally crystallized spot was wrapped in an outer bag, followed by measurements using both X-ray diffractometers. For both instruments, several isosorbide dinitrate-derived peaks were detected only at the crystallized spot, although the signal-to-noise ratio was poorer for the benchtop model. These results show that a high-resolution X-ray diffractometer is advantageous for high-detection sensitivity and offers a high degree of freedom of the measurement position on the sample. It was concluded that a laboratory-level high-resolution X-ray diffractometer can be used to examine the crystalline state of APIs in patches inside an unopened outer bag.

Discovery of Novel Pyrazole Carboxylate Derivatives Containing Thiazole as Potential Fungicides

Inspired by commercially established fluxapyroxad as the lead compound of novel efficient antifungal ingredients, novel pyrazole carboxylate derivatives containing a flexible thiazole backbone were successfully designed, synthesized, and detected for their in vitro and in vivo biological activities against eight agricultural fungi. The antifungal bioassay results showed that compound 24 revealed excellent bioactivities against Botrytis cinerea and Sclerotinia sclerotiorum, with median effective concentrations (EC₅₀) of 0.40 and 3.54 mg/L, respectively. Compound 15 revealed remarkable antifungal activity against Valsa mali, with an EC₅₀ value of 0.32 mg/L. For in vivo fungicide control against B. cinerea and V. mali, compounds 3 and 24 at 25 mg/L, respectively, displayed prominent efficacy on cherry tomatoes and apple branches. Molecular docking results demonstrated that compound 15 could form an interaction with several crucial residues of succinate dehydrogenase (SDH), and the in vitro enzyme assay indicated that the target compound 15 displayed an inhibitory effect toward SDH, with an IC₅₀ value of 82.26 μM. The experimental results indicated that phenyl pyrazole carboxylate derivatives displayed a weak antifungal property and low activity compared to the other title substituent pyrazole carboxylate derivatives. Compounds 3, 15, and 24 are promising antifungal candidates worthy of further fungicide development due to their prominent effectiveness.

Mechanism insight on drug skin delivery from polyurethane hydrogels: Roles of molecular mobility and intermolecular interaction

Though polyurethane (PU) hydrogel had great potential in topical drug delivery system, drug skin delivery behavior from hydrogel and the underlying molecular mechanism were still unclear. In this study, PU and Carbomer (CP as control) hydrogels were prepared with lidocaine (LID) and ofloxacin (OFX) as model drugs. In vitro skin permeation and tissue distribution study were conducted to evaluate the drug delivery behaviors. The underlying molecular mechanisms were characterized by drug release with octanol as release medium, rheological study, ATR-FTIR, NMR, and molecular simulation. The results showed that the skin permeation amount of LID-PU (45.50 ± 7.12 μg) was lower than LID-CP (45.50 ± 7.12 μg). And the LID diffusion coefficient of PU (26.21 μg/h^0.5) was also lower than CP (31.30 μg/h^0.5), which attributed to H-bonding between LID (-CONH) and PU (-NHCOO). However, the OFX-PU showed a higher skin permeation amount (10.06 ± 1.29 μg) than OFX-CP (5.28 ± 1.39 μg). And the OFX-PU also showed a higher diffusion coefficient (30.0 μg/h^0.5) than OFX-CP (21.37 μg/h^0.5), which was caused by increased mobility of hydrogel when interaction action site was C-O-C in PU. In conclusion, drug skin delivery behavior from PU hydrogel was controlled by molecular mobility and intermolecular interaction, which clarified the influence of the functional group of PU hydrogel on drug skin delivery behavior and broadened our understanding of PU hydrogel application in topical drug delivery system.

A comparison study of lipid and polymeric nanoparticles in the nasal delivery of meloxicam: Formulation, characterization, and in vitro evaluation

With the increasingly widespread of central nervous system (CNS) disorders and the lack of sufficiently effective medication, meloxicam (MEL) has been reported as a possible medication for Alzheimer's disease (AD) management. Unfortunately, following the conventional application routes, the low brain bioavailability of MEL forms a significant limitation. The intranasal (IN) administration route is considered revolutionary for CNS medications delivery. The objective of the present study was to develop two types of nanocarriers, poly (lactic-co-glycolic acid) nanoparticles (PLGA NPs) and solid lipid nanoparticles (SLNs), for the IN delivery of MEL adapting the Quality by Design approach (QbD). Turning then to further enhance the optimized nanoformulation behavior by chitosan-coating. SLNs showed higher encapsulation efficacy (EE) and drug loading (DL) than PLGA NPs 87.26% (EE) and 2.67% (DL); 72.23% (EE) and 2.55% (DL), respectively. MEL encapsulated into the nanoformulations improved in vitro release, mucoadhesion, and permeation behavior compared to the native drug with greater superiority of chitosan-coated SLNs (C-SLNs). In vitro-in vivo correlation (IVIVC) results estimated a significant in vivo brain distribution of the nanoformulations compared to native MEL with estimated greater potential in the C-SLNs. Hence, MEL encapsulation into C-SLNs towards IN route can be promising in enhancing its brain bioavailability.

Formulation optimization and characterization of transdermal film of curcumin by response surface methodology

Objective

India is referred as goldmine of herbal drugs but still lack of optimization of herbal drugs, which has kept us on the back foot. The rationale of the study is to prepare optimized transdermal drug delivery system of curcumin employing response surface methodology to study the collective effect of independent variables like concentration of ethyl cellulose, hydroxyl propyl methyl cellulose and dibutyl phthalate which significantly influenced characteristics like percentage elongation and in vitro drug release.

Method

Twenty formulations containing varying concentrations of polymers and permeation enhancer were prepared using solvent casting technique.

Result

The study revealed that the effect of dibutyl phthalate (DBP) concentration was the highest on percentage elongation (P < 0.0001), while hydroxy propyl methyl cellulose (HPMC) concentration exhibited pronounced effect on drug release (P < 0.0001) through dialysis membrane. Linear model fitted the best for curcumin release and elongation for all formulations. According to Derringer’s desirability prediction tool, the composition of optimized film was found to be 242.14% of HPMC, 109.59% of ethyl cellulose (EC), and 1.03% of DBP. Under these conditions, the optimized patch exhibited a predicted value of %elongation and in vitro drug release of 94.35% and 80.0306%, respectively, which was comparable to the actual values of percent elongation and in vitro drug release i.e. 95.02% and 81.03% respectively. FTIR and thermal studies were also performed which revealed no interaction or complexation between drug and excipients. The ex vivo study performed using rat skin showed that the cumulative drug release from the optimized patch showed flux of (30.68 ± 18) µg/cm²/h.

Conclusion

It can be concluded that in future if proper optimization of herbal formulations is carried out, they can become the first choice for patients as compare to synthetic drugs.

Access to thiazoles via [3 + 2] cycloaddition of 1,2,3-thiadiazoles with isonitriles

The formal [3 + 2] cycloaddition of 1,2,3-thiadiazoles with isonitriles is developed to access structurally diverse 4,5-disubstituted thiazoles, in which the thioketene as a sulfo-2C-synthon is first disclosed.

Co-nanoencapsulated meloxicam and curcumin improves cognitive impairment induced by amyloid-beta through modulation of cyclooxygenase-2 in mice

Alzheimer’s disease (AD) is a progressive brain disorder and complex mechanisms are involved in the physiopathology of AD. However, there is data suggesting that inflammation plays a role in its development and progression. Indeed, some non-steroidal anti-inflammatory drugs, such as meloxicam, which act by inhibiting cyclooxygenase-2 (COX-2) have been used as neuroprotective agents in different neurodegenerative disease models. The purpose of this study was to investigate the effects of co-nanoencapsulated curcumin and meloxicam in lipid core nanocapsules (LCN) on cognitive impairment induced by amyloid-beta peptide injection in mice. LCN were prepared by the nanoprecipitation method. Male Swiss mice received a single intracerebroventricular injection of amyloid-beta peptide aggregates (fragment 25–35, 3 nmol/3 μL) or vehicle and were subsequently treated with curcumin-loaded LCN (10 mg/kg) or meloxicam-loaded LCN (5 mg/kg) or meloxicam + curcumin-co-loaded LCN (5 and 10 mg/kg, respectively). Treatments were given on alternate days for 12 days (i.e., six doses, once every 48 hours, by intragastric gavage). Our data showed that amyloid-beta peptide infusion caused long-term memory deficits in the inhibitory avoidance and object recognition tests in mice. In the inhibitory avoidance test, both meloxicam and curcumin formulations (oil or co-loaded LCN) improved amyloid-beta-induced memory impairment in mice. However, only meloxicam and curcumin-co-loaded LCN attenuated non-aversive memory impairment in the object recognition test. Moreover, the beneficial effects of meloxicam and curcumin-co-loaded LCN could be explained by the anti-inflammatory properties of these drugs through cortical COX-2 downregulation. Our study suggests that the neuroprotective potential of meloxicam and curcumin co-nanoencapsulation is associated with cortical COX-2 modulation. This study was approved by the Committee on Care and Use of Experimental Animal Resources, the Federal University of Pampa, Brazil (approval No. 02-2015) on April 16, 2015.

Novel Herbal Topical Patch Containing Curcumin and Arnica montana for the Treatment of Osteoarthritis

BACKGROUND

Osteoarthritis (OA) ranks fifth among all forms of disability affecting 10% of the world population. Current treatments available are associated with multiple side effects and do not slow down the progression of the disease. Moreover, no such effective treatment is available to date in various systems of medicine to treat osteoarthritis. Curcumin and Arnica have shown evident clinical advances in the treatment of osteoarthritis.

OBJECTIVE

The aim of the present study was to design, optimize and characterize novel herbal transdermal patches of curcumin and Arnica montana using factorial design.

METHODS

A multiple factorial design was employed to investigate the effect of hydroxypropyl methyl cellulose, ethyl cellulose and jojoba oil on elongation and drug release. Transdermal patches were evaluated by FTIR, DSC, FESEM, ex vivo drug permeation, anti osteoarthritic activity and analgesic activity.

RESULTS

Independent variables exhibited a significant effect on the physicochemical properties of the prepared formulations. The higher values of drug release and elongation were observed with the higher concentration of hydroxypropyl methylcellulose and jojoba oil. Anti osteoarthritic activity was assessed by complete Freund's adjuvant arthritis model; using rats and analgesic activity by Eddy's hot plate method, using mice. Combination patch exhibited good anti osteoarthritic and analgesic activity as compare to individual drug patches.

CONCLUSION

The design results revealed that the combination patch exhibited good physicochemical, anti osteoarthritic and analgesic activity for the treatment of osteoarthritis in animals. More plants and their combinations should be explored to get reliable, safe and effective formulations that can compete with synthetic drugs.

Development of an optimized febuxostat self-nanoemulsified loaded transdermal film: in-vitro, ex-vivo and in-vivo evaluation

Febuxostat (FBX) is used to treat gout and chronic hyperuricemia. However, its bioavailability is moderate (49%) as a result of low solubility and first-pass metabolism. Therefore, the aim of our study is to improve FBX bioavailability by enhancement its solubility using self-nanoemulsifying drug delivery system (SNEDDS) technique in the form of transdermal film to avoid hepatic metabolism. To accomplish this goal, Eight SNEDDS formulae were prepared according to a three-factor, two-level D-Optimal mixture design to evaluate the effect of different ratios of the Lemon oil (X1), the surfactant Tween-20 (X2), and the co-surfactant PEG-400 (X3) on the globule size in order to reach smallest globular size. Results revealed that SNEDDS globule size ranged from 177 to 454 nm. The optimized formula consisted of 20% oil, 40% surfactant and 40% co-surfactant. Diffusion study showed improved enhancement in skin permeation that was confirmed by imaging using fluorescence microscope. In vivo plasma data showed significant (p < 0.05) difference in FBX plasma levels and pharmacokinetic parameters when compared with raw FBX loaded film. In conclusion, FBX-SNEDDS loaded transdermal film could be a successful way to improve solubility and skin permeability that would lead to improvement in patient's compliance.

Development Of Saquinavir Mesylate Nanoemulsion-Loaded Transdermal Films: Two-Step Optimization Of Permeation Parameters, Characterization, And Ex Vivo And In Vivo Evaluation

Background

Saquinavir mesylate (SQR) tablets are widely used against human immunodeficiency virus. SQR has bioavailability issues owing to its poor aqueous solubility, extensive first-pass metabolism, and even low gastrointestinal tract permeability and absorption.

Objective

An in-depth optimization process was carried out using factorial design to improve the permeation parameters and thereby the bioavailability of SQR by formulating self-nanoemulsifying drug delivery system (SNEDDS)-loaded polymeric transdermal films.

Methods

The solubility of SQR in different nanoemulsion components was examined. Various combinations of selected components were prepared in an extreme vertices mixture design to identify the useful nanoemulsion zone and to develop SNEDDS with minimum globule size. The optimized SQR-SNEDDS was loaded in polyvinyl alcohol (PVA)-based transdermal films. The Box-Behnken design was used to optimize and evaluate SQR permeability. The prepared films were characterized for thickness, tensile strength, elongation, folding endurance, and accelerated stability studies. The optimized film was examined for ex vivo skin permeation and in vivo pharmacokinetic parameters.

Results

The optimized SQR-SNEDDS was prepared in proportions of 0.1, 0.55, and 0.35 of clove oil, labrasol, and Transcutol, respectively. The implemented Box-Behnken design indicated the optimized film consisted of 1.0% PVA, 0.25% propylene glycol, and clove oil as the oil phase. The tensile strength, thickness, percent elongation, and folding endurance of the optimized SQR-SNEDDS film were 0.93 ± 0.013 kg/cm², 0.22 ± 0.006 mm, 43.1 ± 0.022%, and >200 times, respectively. A higher Cmax and double the AUC were observed for SQR-SNEDDS–loaded film in comparison to pure SQR-loaded films.

Conclusion

Implementation of a two-step design to optimize and control experimental factors in the preparation of SQR-SNEDDS and its loading onto PVA-based transdermal films was achieved. The films indicated improved ex vivo skin permeation, enhanced bioavailability, and overcame the limitations of the oral dosage form.

Controlled Release of Lidocaine-Diclofenac Ionic Liquid Drug from Freeze-Thawed Gelatin/Poly(Vinyl Alcohol) Transdermal Patches

The objectives of this work were to prepare a 5 wt% lidocaine-diclofenac ionic liquid drug-loaded gelatin/poly(vinyl alcohol) transdermal patch using a freeze/thaw method and to evaluate its physicochemical properties, in vitro release of lidocaine and diclofenac, and stability test. The lidocaine-diclofenac ionic liquid drug was produced by the ion pair reaction between the hydrochloride salts of lidocaine and the sodium salts of diclofenac. The thermal properties of the final drug product were significantly changed from the primary drugs. The ionic liquid drug could be dissolved in water and mixed in a polymer solution. The resulting transdermal patch was then exposed to 10 cycles of freezing and thawing preparation at - 20°C for 8 h and at 25°C for 4 h, respectively. As a result, it was found that the lidocaine-diclofenac ionic liquid drug-loaded transdermal patch showed good physicochemical properties and could feasibly be used in pharmaceutical applications. The lidocaine-diclofenac ionic liquid drug was not affected by the properties of the transdermal patch due to the lack of chemical interaction between polymer base and drug. The high drug release values of both lidocaine and diclofenac were controlled by the gelatin/poly(vinyl alcohol) transdermal patch. The patch showed good stability over the study period of 3 months when kept at 4°C or under ambient temperature.

Transdermal patches: Design and current approaches to painless drug delivery

Use of transdermal patches can evade many issues associated with oral drug delivery, such as first-pass hepatic metabolism, enzymatic digestion attack, drug hydrolysis and degradation in acidic media, drug fluctuations, and gastrointestinal irritation. This article reviews various transdermal patches available in the market, types, structural components, polymer role, and the required assessment tools. Although transdermal patches have medical applications for smoking cessation, pain relief, osteoporosis, contraception, motion sickness, angina pectoris, and cardiac disorders, advances in formulation development are ongoing to make transdermal patches capable of delivering more challenging drugs. Transdermal patches can be tailored and developed according to the physicochemical properties of active and inactive components, and applicability for long-term use. Therefore, a number of chemical approaches and physical techniques for transdermal patch development are under investigation.

Localized and targeted delivery of NSAIDs for treatment of inflammation: A review

IMPACT STATEMENT

This work provides an overview of research currently being done exploring potential drug delivery device strategies for NSAIDs as an alternative to systemic delivery. Commentary on this field is made in an attempt to aid future experimental design, enabling researchers to determine the drugs and delivery vehicles which are most advantageous for them to pursue, as well as suggestions to standardize the reporting of such future research.

A novel albumin wrapped nanosuspension of meloxicam to improve inflammation-targeting effects

Background

The objective of this study was to develop a more bio-available and safe nanosuspension of meloxicam (MX), which could dramatically improve inflammation targeting.

Methods and results

MX-loaded bovine serum albumin (BSA) nanosuspensions were prepared using acid–base neutralization in aqueous solution and the prepared nanosuspensions were characterized. The results obtained showed that the prepared nanosuspensions had a narrow size distribution with a mean particle size of 78.67±0.22 nm, a polydispersity index of 0.133±0.01, and a zeta potential of −11.87±0.91 mV. The prepared MX nanosuspensions were spherically wrapped by BSA with a smooth surface as shown by transmission electron microscopy. Stability studies showed that the nanosuspensions were physically stable at 4°C with a shelf life of at least 6 months. In the in vitro dissolution test, the MX-loaded BSA nanosuspension (MX-BSA-NS) exhibited sustained release. In addition, an in vivo pharmacokinetic study in rats following intravenous injection showed that the half-life (t_1/2), mean residence time (MRT), and area under the concentration–time curve (AUC_0–∞) of MX-BSA-NS was increased by 169.83%, 150.13%, and 148.80%, respectively, in comparison with MX conventional solution (MX solution). Furthermore, results from inflammation targeting studies showed that the concentration of MX increased significantly in inflamed tissues but was reduced in normal tissues compared with the MX solution group after injection of MX-BSA-NS.

Conclusion

The prepared MX-BSA-NS significantly increased the inflammation-targeting properties and bioavailability of MX, suggesting its potential as a promising formulation for the targeted drug delivery of MX in future clinical applications.

Cocrystallization as a novel approach to enhance the transdermal administration of meloxicam

Despite its large effectiveness, the long-term oral administration of high doses of meloxicam (MLX) may lead to gastrointestinal events such as abdominal pain, diarrhea, dyspepsia, ulceration, hemorrhage, and gastrointestinal perforation. Moreover, the pH-dependent solubility of MLX makes the development of new oral formulations even more challenging. As an alternative to overcome these limitations, the transdermal delivery of this drug has been purposed. Although various physical and chemical approaches to enhance the absorption of MLX may be found in literature, the use of cocrystallization has not been reported so far. Cutaneous permeation of MLX and 1:1 meloxicam-salicylic acid cocrystal (MLX-SLC) were evaluated using Franz diffusion cells. Cocrystal was suspended in an aqueous solution and in a gel to evaluate the vehicle effect on permeation parameters. In aqueous medium, the cocrystallization showed to enhance the drug permeation coefficient from 1.38 to 2.15 × 10^-3 cm/h. MLX-SLC generated supersaturation with respect to the drug during dissolution studies simulating the conditions in the Franz cell donor chamber. This greater amount of free drug in the solution could contribute to explain the higher transdermal absorption and shorter lag time of this system. In addition, the acidic coformer ionization led to a pH reduction from 7.4 to 5.8, which, in turn, provided an increase in the unionized species of the drug, enhancing its permeation rate. The gel containing cocrystals reduced MLX permeation rate significantly (P = 0.42 × 10^-3 cm/h), which was attributed to its higher viscosity.

Enhanced transdermal delivery of meloxicam by nanocrystals: Preparation, in vitro and in vivo evaluation

Meloxicam (MLX) is efficient in relieving pain and inflammatory symptoms, which, however, is limited by the poor solubility and gastrointestinal side effects. The objective of this study is to develop a nanocrystal formulation to enhance transdermal delivery of MLX. MLX nanocrystals were successfully prepared by the nanoprecipitation technique based on acid-base neutralization. With poloxamer 407 and Tween 80 (80/20, w/w) as mixed stabilizers, MLX nanocrystals with particle size of 175 nm were obtained. The crystalline structure of MLX nanocrystals was confirmed by both differential scanning calorimetry and X-ray powder diffractometry. However, the nanoprecipitation process reduced the crystallinity of MLX. Nanocrystals increased both in vitro and in vivo transdermal permeation of MLX compared with the solution and suspension counterparts. Due to the enhanced apparent solubility and dissolution as well as the facilitated hair follicular penetration, nanocrystals present a high and prolonged plasma MLX concentration. And 2.58- and 4.4-fold increase in AUC_0→24h was achieved by nanocrystals comparing with solution and suspension, respectively. In conclusion, nanocrystal is advantageous for transdermal delivery of MLX.

Polymeric nanocapsules as a technological alternative to reduce the toxicity caused by meloxicam in mice

This study determined whether meloxicam in nanocapsules modifies stomach and liver damage caused by free meloxicam in mice. Male Swiss mice were treated with blank nanocapsules or meloxicam in nanocapsules or free meloxicam (10 mg/kg, intragastrically, daily for five days). On the seventh day, blood was collected to determine biochemical markers (glutamic oxaloacetic transaminase, glutamic pyruvic transaminase, total bilirubin, unconjugated bilirubin, albumin and alkaline phosphatase). Stomachs and livers were removed for histological analysis. There was no significant difference in the biochemical markers in the plasma of mice. Meloxicam in nanocapsules did not have an ulcerogenic potential in the stomach or cause lipid peroxidation in the stomach and liver. Free meloxicam increased the ulcerogenic potential in the stomach and lipid peroxidation in the stomach and liver. Meloxicam in nanocapsules caused less histological changes than free meloxicam. In conclusion, polymeric nanocapsules can represent a technological alternative to reduce the toxicity caused by meloxicam.

Assessment of simvastatin niosomes for pediatric transdermal drug delivery

The prevalence of childhood dyslipidemia increases and is considered as an important risk factor for the incidence of cardiovascular disease in the adulthood. To improve dosing accuracy and facilitate the determination of dosing regimens in function of the body weight, the proposed study aims at preparing transdermal niosomal gels of simvastatin as possible transdermal drug delivery system for pediatric applications. Twelve formulations were prepared to screen the influence of formulation and processing variables on critical niosomal characteristics. Nano-sized niosomes with 0.31 μm number-weighted size displayed highest simvastatin release rate with 8.5% entrapment capacity. The niosomal surface coverage by negative charges was calculated according to Langmuir isotherm with n = 0.42 to suggest that the surface association was site-independent, probably producing surface rearrangements. Hypolipidemic activities after transdermal administration of niosomal gels to rats showed significant reduction in cholesterol and triglyceride levels while increasing plasma high-density lipoproteins concentration. Bioavailability estimation in rats revealed an augmentation in simvastatin bioavailability by 3.35 and 2.9 folds from formulation F3 and F10, respectively, compared with oral drug suspension. Hence, this transdermal simvastatin niosomes not only exhibited remarkable potential to enhance its bioavailability and hypolipidemic activity but also considered a promising pediatric antihyperlipidemic formulation.

Transdermal delivery of meloxicam using niosomal hydrogels: in vitro and pharmacodynamic evaluation

Non-ionic surfactant vesicles were prepared using Span-60 and cholesterol in the mass ratios of 1:1, 2:1, 1:2 and 3:1 for transdermal delivery of an anti-inflammatory drug meloxicam (MXM). The drug encapsulation efficiencies and particle size were observed in the range of 32.9-80.7% and 56.5-133.4 nm, respectively. Three different gel bases were also prepared using Poloxamer-407, Chitosan and Carbopol-934 as polymers to study the performance of the in vitro release of the drug. Prepared gels were also converted into niosomal gels. In vitro release characteristics of MXM from different gels were carried out using dialysis membrane in phosphate buffer (pH 7.4). The poloxamer-407 gel or niosomal poloxamer-407 gel showed the superior drug release over the other formulations. The release data were treated with various mathematical models to assess the relevant parameters. The results showed that the release of MXM from the prepared gels and niosomal gels followed Higuchi's diffusion model. The flux of MXM was found to be independent on the viscosity of the formulations. The anti-inflammatory effects of MXM from different niosomal gel formulations were evaluated using carrageenan-induced rat paw edema method, which showed superiority of niosomal gels over conventional gels.

Optimization of self-nanoemulsifying systems for the enhancement of in vivo hypoglycemic efficacy of glimepiride transdermal patches

OBJECTIVES

To optimize and use of glimepiride (GMD)-loaded self-nanoemulsifying delivery systems (SNEDs) for the preparation of transdermal patches.

METHODS

Mixture design was utilized to optimize GMD-loaded SNEDs in acidic and aqueous pH media. Optimized GMD-loaded SNEDs were used in the preparation of chitosan (acidic) and hydroxypropyl methyl cellulose (HPMC) (aqueous) films. The prepared optimized formulations were investigated for ex vivo skin permeation, for in vivo hypoglycemic activity and for their pharmacokinetic parameters using animal model.

RESULTS

The optimized formulations showed flux value of (2.88 and 4.428 μg/cm(2)/h) through rat skin for chitosan and HPMC films, respectively. The pattern of GMD release from both formulations was in favor of Higuchi and approaching zero order models. The n values for Korsmeyer-Peppas equation were characteristic of anomalous (non-Fickian) release mechanism. Moreover, HPMC patches have shown significant reductions (p < 0.05) in blood glucose levels; (213.33 ± 15.19) mg/100 ml from the base-line measurement after 12 h of application.

CONCLUSIONS

Optimized GMD SNEDs patches were found to improve GMD skin permeability and the essential pharmacokinetic parameters. Further extensive pre/clinical studies are necessary prior to use transdermal GMD as a valuable alternative to peroral dosage forms with improved bioavailability, longer duration of action and more patient convenience.

Enhanced anti-inflammatory activity of carbopol loaded meloxicam nanoethosomes gel

The aim of the current investigation is to develop nanoethosomes for transdermal meloxicam delivery. The ethosomes were prepared by varying the variables such as concentrations of phospholipids 90G, ethanol, and sonication time while entrapment efficiency, vesicle size and transdermal flux were the chosen responses. Results indicate that the nanoethosomes of meloxicam provides lesser vesicles size, better entrapment efficiency and improved flux for transdermal delivery as compared to rigid liposomes. The optimized formulation (MCEF-OPT) obtained was further evaluated for an in vivo anti-inflammatory activity in rats. Optimized nanoethosomal formulation with vesicles size of 142.3nm showed 78.25% entrapment efficiency and achieved transdermal flux of 10.42μg/cm(2)/h. Nanoethosomes proved to be significantly superior in terms of, amount of drug permeated into the skin, with an enhancement ratio of 3.77 when compared to rigid liposomes. In vivo pharmacodynamic study of carbopol(®) loaded nanoethosomal gel showed significant higher percent inhibition of rat paw edema compared with oral administration of meloxicam. Our results suggest that nanoethosomes are an efficient carrier for transdermal delivery of meloxicam.

Evaluation of meloxicam-loaded cationic transfersomes as transdermal drug delivery carriers

The aim of this study is to develop meloxicam (MX)-loaded cationic transfersomes as skin delivery carriers and to investigate the influence of formulation factors such as cholesterol and cationic surfactants on the physicochemical properties of transfersomes (i.e., particle size, size distribution, droplet surface charge and morphology), entrapment efficiency, stability of formulations and in vitro skin permeation of MX. The transfersomes displayed a spherical structure. Their size, charge, and entrapment efficiency depended on the composition of cholesterol and cationic surfactants in the formulation. Transfersomes provided greater MX skin permeation than conventional liposomes and MX suspensions. The penetration-enhancing mechanism of skin permeation by the vesicles prepared in this study may be due to the vesicle adsorption to and/or fusion with the stratum corneum. Our results suggest that cationic transfersomes may be promising dermal delivery carriers of MX.

A thermoplastic elastomer patch matrix for traditional Chinese medicine: design and evaluation

OBJECTIVE

To design and evaluate a novel pressure sensitive adhesive (PSA) patch containing traditional Chinese medicine (TCM) using styrene-isoprene-styrene (SIS) copolymer.

METHOD

A mixture D-optimal design with ternary response surface diagram was employed in the optimization process. The proportions of SIS copolymer, tackifying resin and plasticizer were selected as the independent variables while tack force, peel strength of the patch and skin penetrability of methyl salicylate were selected as the dependent variables. The optimized patch was then evaluated including in vivo absorption, pharmacological activities and skin irritation, by comparing with a commercial patch based on natural rubber.

RESULTS

The optimized patch, which comprised 30.0% SIS copolymer, 26.6% tackifying resin and 43.4% plasticizer, was superior to commercial patch in skin permeation, pharmacological activities and skin biocompatibility.

CONCLUSION

SIS copolymer was a suitable substitute to natural rubber in producing patches containing TCM formula.

Development of meloxicam in situ implant formulation by quality by design principle

OBJECTIVE

The focus of this study was to develop and optimize in situ implant formulation of meloxicam by quality by design (QbD) principle for long-term management of musculoskeletal inflammatory disorders.

METHODS

The formulation was optimized by Box-Behnken design with polylactide-co-glycolide (PLGA) level (X1), N-methyl pyrrolidone level (X2) and PLGA intrinsic viscosity (X3) as the independent variables and initial burst release of drug (Y1), cumulative release (Y2), and dissolution efficiency (Y3) as the dependent variables. The formulation was physicochemically characterized by scanning electron microscopy (SEM), Fourier transform infrared (FT-IR) spectroscopy and powder X-ray diffraction (PXRD). Pharmacokinetic studies of the optimized formulation were performed on Sprague-Dawley rats.

RESULTS

Y1 was significantly affected by X2 and X3. Y2 was affected by X1 and X3 while Y3 was affected by all three independent variables employed in the formulations. Responses for the optimized formulation were in close agreement with the values predicted by the model. SEM photomicrographs indicated uniform gel formulation. No chemical interaction between the components of formulation was observed by FT-IR and meloxicam was found to be present in the amorphous form in the gel matrix as revealed by PXRD. The maximum plasma concentration (Cmax), time to achieve Cmax and area under plasma concentration curve were significantly different from those of the solution formulation used as the control. Plasma concentration of meloxicam was maintained above its IC50 concentration required for COX-2 inhibition for 23 days.

CONCLUSION

Meloxicam in situ implant may provide long-term management of inflammatory conditions with improved patient compliance and better therapeutic index.

A drug-in-adhesive matrix based on thermoplastic elastomer: evaluation of percutaneous absorption, adhesion, and skin irritation

A novel drug-in-adhesive matrix was designed and prepared. A thermoplastic elastomer, styrene-isoprene-styrene (SIS) block copolymer, in combination with tackifying resin and plasticizer, was employed to compose the matrix. Capsaicin was selected as the model drug. The drug percutaneous absorption, adhesion properties, and skin irritation were investigated. The results suggested that the diffusion through SIS matrix was the rate-limiting step of capsaicin percutaneous absorption. [SI] content in SIS and SIS proportions put important effects on drug penetration and adhesion properties. The chemical enhancers had strong interactions with the matrix and gave small effect on enhancement of drug skin permeation. The in vivo absorption of samples showed low drug plasma peaks and a steady and constant plasma level for a long period. These results suggested that the possible side effects of drug were attenuated, and the pharmacological effects were enhanced with an extended therapeutic period after application of SIS matrix. The significant differences in pharmacokinetic parameters produced by different formulations demonstrated the influences of SIS copolymer on drug penetrability. Furthermore, the result of skin toxicity test showed that no skin irritation occurred in guinea pig skin after transdermal administration of formulations.