Formulation and evaluation of clotrimazole transdermal spray

Context: Transdermal spray (TS) of clotrimazole (CTZ) was formulated to improve the drug transport through the skin up to 12?h to achieve the antifungal efficacy.

Objective: The aim of present study was to formulate and evaluate antifungal transdermal spray to improve the permeation of clotrimazole across the skin and to decrease the dosing frequency in fungal infection.

Materials and methods: Different ratios of ethanol and acetone and various grades of eudragit and ethyl cellulose were evaluated according to six criteria: viscosity, drying time, stickiness, appearance and integrity on skin and water washability. Propylene glycol (PG) and polyethylene glycol 400 (PEG 400) were used in the study as plasticizer and solubilizer. The TS was evaluated for in vitro drug release, spray angle, spray pattern, average weight per dose, pH, drug content, evaporation time, leak test and antifungal efficacy study.

Results and discussion: Eudragit E100 and blend of ethanol and acetone (80:20) satisfied the desired criteria. The selection of optimized batch was based on the results of in vitro drug release, spray pattern and spray angle. The optimized batch showed the spray angle <85° and uniform spray pattern. The formulation containing PG showed higher drug release than PEG 400. The inclusion of eutectic mixture consisting of camphor and menthol (1:1) showed improved drug transport through the rat skin and larger mean zone of inhibition indicating the improved antifungal efficacy.

Conclusion: The TS of CTZ can be an innovative and promising approach for the topical administration in the fungal diseases.     

Development and evaluation of topical films containing phytoestrogenic diaryheptanoids from Curcuma comosa extract

Rational: Phytoestrogens have been found to delay signs of skin aging in post-menopausal women, in a way similar to the effects of estrogens. Diarylheptanoids from a rhizome of traditional Thai herb named Curcuma comosa is considered to be a novel class of phytoestrogens.

Objectives: The aims of this study were to prepare effective topical films using mixed types and vary ratios of hydrophobic (Eudragit RL, Eudragit RS, and Eudragit NE) and hydrophilic polymer (hydroxylpropyl methycellulose, HPMC) with Transcutol as a permeation enhancer for delivery of diarylheptanoids to improve signs of skin aging in post-menopausal women.

Material and methods: Topical films were characterized for their physical and mechanical properties. In vitro release, skin permeation and accumulation were evaluated using Franz diffusion cell and the concentrations of diarylheptanoids were determined using high-performance liquid chromatography.

Results: The combined formulations between HPMC and Eudragit NE showed the satisfactory physical and mechanical properties, and also provided the highest amount of drug released compared to Eudragit RL and Eudragit RS. When the proportion of HPMC amount in the polymer matrix increased, the cumulative drug release also increased (HPMC: Eudragit NE 6:4?>?5:5?>?4:6). Moreover, they provided a high accumulation of diarylheptanoids within skin when using transcutol as a permeation enhancer.

Conclusion: The obtained data provided the skin permeation and accumulation behavior of diarylheptanoids, indicating the feasibility of a skin delivery of the C. comosa extract. The developed films might be topically used as an alternative therapy for protection of skin aging in peri and post-menopausal women.     

Practical Considerations for Compendial Method Selection

Abstract

The objective of this study was to develop and validate an in vitro test method that can be used as a tool for accessing batch-to-batch uniformity of finished topical products. The studies were performed by utilizing topical creams containing the 13-cis isomer of retinoic acid. Various physicochemical factors which may affect drug release from topical cream formulations were evaluated including drug concentration, internal phase droplet size distribution, viscosity and the composition of the emulsion internal and external phases. Utilizing a modified Franz diffusion cell with a cellulose membrane, the in vitro drug release profile from various cream formulations was established

The effect of varying the concentrations of various key ingredients by 30% does affect the viscosities and release rates compared to a standard formulation. However, there is no correlation between the viscosities and the release rates. No significant differences in pH and droplet size distribution were observed in these cream formulations compared to a standard formulation. The oil phase volume ratio appears to have the largest influence on the in vitro release of the drug. Intra- and inter-batch comparisons of the finished cream products show reproducible release profiles. Based on the results obtained in this study, when used together, both in vitro release and viscosity measurements may be useful as tools to assess batch-to-batch uniformity and consistent manufacturing of the finished cream product     

Development of a Soluplus budesonide freeze-dried powder for nasal drug delivery

Objective: The aim of this work was to develop an amorphous solid dispersions/solutions (ASD) of a poorly soluble drug, budesonide (BUD) with a novel polymer Soluplus^® (BASF, Germany) using a freeze-drying technique, in order to improve dissolution and absorption through the nasal route.

Significance: The small volume of fluid present in the nasal cavity limits the absorption of a poorly soluble drug. Budesonide is a corticosteroid, practically insoluble and normally administered as a suspension-based nasal spray.

Methods: The formulation was prepared through freeze-drying of polymer-drug solution. The formulation was assessed for its physicochemical (specific surface area, calorimetric analysis and X-ray powder diffraction), release properties and aerodynamic properties as well as transport in vitro using RPMI 2650 nasal cells, in order to elucidate the efficacy of the Soluplus–BUD formulation.

Results: The freeze-dried Soluplus–BUD formulation (LYO) showed a porous structure with a specific surface area of 1.4334?±?0.0178 m²/g. The calorimetric analysis confirmed an interaction between BUD and Soluplus and X-ray powder diffraction the amorphous status of the drug. The freeze-dried formulation (LYO) showed faster release compared to both water-based suspension and dry powder commercial products. Furthermore, a LYO formulation, bulked with calcium carbonate (LYO-Ca), showed suitable aerodynamic characteristics for nasal drug delivery. The permeation across RPMI 2650 nasal cell model was higher compared to a commercial water-based BUD suspension.

Conclusions: Soluplus has been shown to be a promising polymer for the formulation of BUD amorphous solid suspension/solution. This opens up opportunities to develop new formulations of poorly soluble drug for nasal delivery.     

Selection of excipient,solvent and packaging to optimize the performance of spray-dried formulations: case example fenofibrate

Context: Along with other options, solid dispersions prepared by spray drying offer the possibility of formulating poorly soluble drugs in a rapidly dissolving format. As a wide range of potential excipients and solvents is available for spray drying, it is usually necessary to carry out a comprehensive array of studies to arrive at an optimal formulation.

Objective: To study the influence of formulation parameters such as co-sprayed excipients, solvents and packaging on the manufacture, in vitro performance and stability of spray-dried oral drug products using fenofibrate as a model drug.

Materials and methods: Solid dispersions of fenofibrate with different amorphous polymers were manufactured from two solvent systems by spray drying. These were characterized in terms of physicochemical properties, crystalline content and dissolution behavior in biorelevant media upon production and after storage in two packaging systems (Glass and Activ-Vials^?).

Results and discussion: Spray drying the same formulation from two different solvents led to different physicochemical properties, dissolution behavior and long-term stability. The dissolution behavior and long-term stability also varied significantly among excipients. The viscosity of the polymer and the packaging material proved to be important to the long-term stability.

Conclusion: For spray-dried products containing fenofibrate, the excipients were ranked according to dissolution and stability performance as follows: PVP derivatives >> HPMC 2910/15, HPMCAS-MF, HP-β-CD >> PVP:PVA 2:8. EtOH 96% proved superior to acetone/water for spray drying with polymers. The results were used to propose a general approach to developing spray-dried formulations of poorly soluble drugs.     

The Release Rate of Indomethacin from Solid Dispersions with Eudragite

Abstract

The coprecipitates were prepared by a solvent technique using Eudragit E as carrier and indomethacin as a model drug.

X-Ray diffractometry, differential scanning calorimetry (DSC) and wettability tests were employed to investigate the physical state of the studied formulations. Up to 50% of indomethacin can be dispersed in an amorphous state in Eudragit E.

The influence of the pH on the in vitro release of solid dispersions has been evaluated. Because of the good solubility of Eudragit E at pH 1.2 a fast dissolution rate of the drug was observed while a marked delay was noticed at pH 7.5 where the polymer is only permeable to water. At pH 5.8 the kinetics of drug release can be modulated by the drug/polymer ratio. The dissolution rate of the drug can be increased by decreasing its amount in the coevaporate.     

Preparation of polymer-blended quinine nanocomposite particles by spray drying and assessment of their instrumental bitterness-masking effect using a taste sensor

Abstract

Context: The development of taste-masking technologies for foods and drugs is essential because it would enable people to consume and receive healthy and therapeutic effect without distress.

Objective: In the current study, in order to develop a novel method to prepare nanocomposite particles (microparticles containing bitter nanoparticles) in only one step, by using spray drying, a two-solution mixing nozzle-equipped spray dryer that we previously reported was used. The nanocomposite particles with or without poorly water-soluble polymers prepared using our spray-drying technique were characterized.

Methods: (1) The organic solution containing quinine, a model of bitter compound and poorly water-soluble polymers and (2) sugar alcohol (mannitol) aqueous solution were separately flown in tubes and two solutions were spray dried through two-solution type spray nozzle to prepare polymer-blended quinine nanocomposite particles. Mean diameters of nanoparticles, taste-masking effect and dissolution rate of quinine were evaluated.

Results: The results of taste masking by taste sensor suggested that the polymer (Eudragit EPO, Eudragit S100 or Ethyl cellulose)-blended quinine nanocomposite particles exhibited marked masking of instrumental quinine bitterness compared with the quinine nanocomposite particles alone. Quinine nanocomposite formulations altered the quinine dissolution rate, indicating that they can control intestinal absorption of quinine.

Conclusion: These results suggest that polymer-blended quinine composite particles prepared using our spray-drying technique are useful for masking bitter tastes in the field of food and pharmaceutical industry.     

Preparation and In Vitro/In Vivo Evaluation of Gliclazide Loaded Eudragit Nanoparticles as a Sustained Release Carriers

ABSTRACT

The aim of this study was to formulate and optimize gliclazide-loaded Eudragit nanoparticles (Eudragit L100 and Eudragit RS) as a sustained release carrier with enhanced efficacy. Eudragit L 100 nanoparticles (ELNP) were prepared by controlled precipitation method whereas Eudragit RSPO nanoparticles (ERSNP) were prepared by solvent evaporation method. The influence of various formulation factors (stirring speed, drug:polymer ratio, homogenization, and addition of surfactants) on particle size, drug loading, and encapsulation efficiency were investigated. The developed Eudragit nanoparticles (L100 and RS) showed high drug loading and encapsulation efficiencies with nanosize. Mean particle size altered by changing the drug:polymer ratio and stirring speed. Addition of surfactants showed a promise to increase drug loading, encapsulation efficiency, and decreased particle size of ELNP as well as ERSNP. Dissolution study revealed sustained release of gliclazide from Eudragit L100 as well as Eudragit RSPO NP. SEM study revealed spherical morphology of the developed Eudragit (L100 and RS) NP. FT-IR and DSC studies showed no interaction of gliclazide with polymers. Stability studies revealed that the gliclazide-loaded nanoparticles were stable at the end of 6 months. Developed Eudragit NPs revealed a decreased t_min (ELNP), and enhanced bioavailability and sustained activity (ELNP and ERSNP) and hence superior activity as compared to plain gliclazide in streptozotocin induced diabetic rat model and glucose-loaded diabetic rat model. The developed Eudragit (L100 and RSPO) NP could reduce dose frequency, decrease side effects, and improve patient compliance.     

Dry powder nasal drug delivery: challenges,opportunities and a study of the commercial Teijin Puvlizer Rhinocort device and formulation

Purpose: To discuss the challenges and opportunities for dry powder nasal medications and to put this in to perspective by evaluating and characterizing the performance of the Teijin beclomethasone dipropionate (BDP) dry powder nasal inhaler; providing a baseline for future nasal products development.

Methods: The aerosol properties of the formulation and product performance of Teijin powder intranasal spray were assessed, with a particular focus on particle size distribution (laser diffraction), powder formulation composition (confocal Raman microscope) and aerosol performance data (British Pharmacopeia Apparatus E cascade impactor, aerosol laser diffraction).

Results: Teijin Rhinocort^® (BDP) dry powder spray formulation is a simple blend of one active ingredient, BDP with hydroxypropylcellulose (HPC) carrier particles and a smaller quantity of lubricants (stearic acid and magnesium stearate). The properties of the blend are mainly those of the carrier (D_v50?=_?98?±?1.3?µm). Almost the totality of the capsule fill weight (96.5%) was emitted with eight actuations of the device. Using the pharmacopeia suggested nasal chamber deposition apparatus attached to an Apparatus E impactor. The BDP main site of deposition was found to be in the nasal expansion chamber (90.2?±?4.78%), while 4.64?±?1.38% of the BDP emitted dose was deposited on Stage 1 of the Apparatus E.

Conclusions: The Teijin powder nasal device is a simple and robust device to deliver pharmaceutical powder to the nasal cavity, thus highlighting the robustness of intranasal powder delivery systems. The large number of actuations needed to deliver the total dose (eight) should be taken in consideration when compared to aqueous sprays (usually two actuations), since this will impact on patient compliance and consequently therapeutic efficacy of the formulation.     

Development and Optimization of a Methotrexate Topical Formulation

Abstract

A topical methotrexate (MTX) formulation that would achieve optimal drug buildup in the epidermis and diminish potential systemic toxicity could be of great utility in the treatment of a variety of hyperproliferative skin disorders. In an attempt to develop an optimized MTX topical formulation containing pharmaceutically acceptable excipients, a 2³ factorial design was used to investigate the effects of a fatty alcohol, propylene glycol, and ethanol on the in vitro skin permeation and uptake of MTX. In vitro skin permeation studies were performed using excised human epidermis mounted in flow-through diffusion cells. The results of steady-state flux and skin uptake of MTX from these formulations ranged from 0.035 to 0.315 μg/cm²/hr and 1.146 to 7.929 μg/cm², respectively. Response surface analysis was used to determine the optimum formulation in terms of skin permeation and uptake of MTX.

An optimized cream formulation was developed and compared to a gel formulation containing 3% Azone in hairless mice to evaluate the uptake of MTX in the treated and untreated skin sites as well as the distribution of MTX in the blood and liver following topical application. The results of the in vivo study demonstrated the localization of MTX at the treated site for both formulations without significant uptake of MTX in the distant untreated epidermis and dermis. The levels of MTX in the blood and liver following topical application of the optimized cream were significantly less than those of the gel formulation with 3% Azone.     

Controlled Release Salbutamol Sulphate Molded Tablets Using Eudragit Retard

Abstract

Permeable acrylic resins were used as efficient retarding materials to prepare controlled release salbutamol sulphate molded tablets. The formulation is simple, efficient, economic and is easily shaped into molded tablets. The effects of two types of acrylic resins, namely: Eudragit RL100 ad Eudragit RS100 in concentrations 1, 2 and 5% w/w on the physical characteristics as well as on the in vitro release patterns of salbutamol sulphate from molded tablets prepared with either polyethylene glycol (PEG) 4000 or 6000 were studied. It was revealed that, as the molecular weight of the PEG increased, the hardness of the tablets increased. Considerable retardation in the drug release was observed by using Eudragit RS100 as compared to Eudragit RL100. The formulation prepared with PEG 6000 and 5% Eudragit RS100 produced much more release time prolongation than the other tested formulations. On the other hand, tablets prepared by the direct compression technique produced a faster release of salbutamol sulphate than those prepared by molding.     

Preparation and Evaluation of Sustained-Release Solid Dispersions of Drugs with Eudragit Polymers

Abstract

Coevaporates of paracetamol and rifampicin with Eudragit polymers of different natures (anionic, cationic, and zwitterionic) were prepared. Determination of dissolution rate of these coevaporates in dissolution media simulating those of the gastrointestinal tract (GIT) revealed that the release rate of paracetamol is retarded from all the coevaporates studied. In this respect, Eudragit L100-SS shows the highest sustainment of drug release, while Eudragit E100 shows the lowest. Conversely, the release of rifampicin from its coevaporates with the anionic Eudragit S100 polymer is more retarded than the corresponding coevaporate with the zwitterionic Eudragit RL100 or from coevaporates with equal mixtures of the two polymers.

Increasing the polymer weight fraction in rifampicin coevaporates with Eudragit S100 up to 0.5 resulted in a corresponding decrease in the dissolution rate. However, beyond this weight fraction, the polymer effect on the dissolution rate of the drug becomes minimized. The results confirmed that the process of dissolution of the two drugs from their coevaporates is a diffusion-controlled release process.

The biological performance of paracetamol coevaporates was monitored in rabbits; paracetamol level in plasma was found to follow first-order kinetics. for all the investigated paracetamol coevaporates, the peak plasma level was less than 50 μg/ml compared to a value of 60, μg/ml for the drug per se. The coevaporates of the drug with Eudragit L100-55 showed slowest rates of absorption and elimination as well as greatest half-peak and half-life times. Biological peformance of rifampicin coevaporates was assessed in human subjects receiving a single oral dose equivalent to 300 mg of the drug. The results depicted sustainment of drug release as a function of polymer weight fraction. A strict correlation was shown to exist between the total amount of drug excreted during 24 hr post dosing of the coevaporates and its in vitro dissolution rate.

The results depicted that paracetamol can be formulated in the form of a coevaporate with Eudragit L100-55 to prepare a more safe sustained-release formulation with minimal side effects, and also revealed the advantages of administration of rifampicin in the form of a coevaporate with Eudragit S100 (4:1) at a single oral dose equivalent to 600 mg of drug.     

Preparation of an optimized ciprofloxacin-loaded chitosan nanomicelle with enhanced antibacterial activity

Objective: The objective of this study was to evaluate the effect of lipid structure on physicochemical properties of chitosan-fatty acid nanomicelles and prepare an optimum ciprofloxacin-loaded formulation from these conjugates which could enhance the antibacterial effects of drug against some important pathogens like P. aeruginosa.

Significance: Nowadays, resistance in infectious diseases is a growing worldwide concern. Nanocarriers can increase the therapeutic index and consequently reduce the antibiotic resistance. By site-specific delivery of drug, the adverse effects of broad-spectrum antibiotics such as ciprofloxacin would be reduced.

Methods: Fatty acid grafted chitosan conjugates were synthetized in the presence of 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide. The effects of fatty acid type (stearic acid, palmitic acid, and linoleic acid) on physicochemical properties of conjugates were investigated. Ciprofloxacin was encapsulated in nanomicelles by thin film hydration method. Also, the preparation process was optimized with a central composite design. The antibacterial effect of optimum formulation against P. aeruginosa, K. pneumoniae, and S. pneumoniae species was determined.

Results: All conjugates were synthetized with high yield values and the substitution degrees ranged between 2.13 and 35.46%. Ciprofloxacin was successfully encapsulated in nanomicelles. The optimum formulation showed high drug loading (≈?19%), with particle size of about 260?nm and a sustained release profile of ciprofloxacin. The minimum inhibitory concentrations of ciprofloxacin in optimum formulation against P. aeruginosa and K. pneumoniae species were 4 and 2 times lower in comparison with the free drug, respectively.

Conclusions: The antibacterial effect of ciprofloxacin was improved by encapsulation of drug in chitosan nanomicelles.     

Preparation and dissolution characteristics of controlled release diltiazem pellets

Abstract

Different series of Diltiazem pellets with slow release of the active substance were prepared, by pan coating technique, using different mixtures of acrylic polymers (Eudragit E, Eudragit L, Eudragit RL and Eudragit RS) as film coating agents. The thickness of the coatings were varied by different amounts of Eudragit. Release profiles of Diltiazem hydrochloride were investigated using USP XX rotating basket method (Erweka DT-D6) with 1000 ml buffer solution (pH values 1.5; 2.2; 5.5; 6.8; 7.0) at 37°C as solvent. In vitro dissolution findings showed that Eudragit coatings gave prolonged release of Diltiazem hydrochloride. The permeability of coatings in gastric and intenstinal juices was found to be influenced by the amount of Eudragit L in the formulation. Also, the drug release rate was found to be dependent on the amount of coating applied. In order to understand the drug release mechanism better, the release data were tested assuming common kinetic models. In the present study square - root of the time plots and Weibull plots were not sufficiently linear, although several correlation coefficients were high. When the goodness of fit of release data to first - order kinetics and Hixson - Crowell ‘s equation was evaluated, the difference between these two models was often noted to be minimal.     

Sustained Release Tablet Formulation for a New Iron Chelator

Abstract

Sustained release tablet formulations for a new orally active iron chelator (1, 2, dimethyl-3-hydroxy-pyrid-4-one, DMHP or L1) have been developed. Coprecipitates containing DMHP and polymer were prepared and compressed into matrix-type tablets. The dissolution profiles as a function of (1) the type of polymer, and (2) polymer content, were determined. Both Eudragit types (RLPM and RSPM) and all hydroxypropylmethylcellulose (HPMC) grades (E4M, E10M, and K4M) exhibited significant sustained release activity. Above a certain ratio, increase in the polymer concentration did not provide any further decrease in the release rates. All grades of HPMC and both Eudragit RSPM and RLPM showed non-Fickian release kinetics. The role of HPMC and Eudragits in the formulation of a sustained release tablet of a water soluble drug is demonstrated.     

Exploring the antioxidant potentiality of two food by-products into a topical cream: stability,in vitro and in vivo evaluation

Abstract

Context: Coffee silverskin (CS), a food by-product of the coffee roasting industry, has been studied as an active ingredient for skin care products due to its high potential of antioxidant activity and low cytotoxicity. Another food waste used as ingredient with promising characteristics is obtained from Medicago sativa (MS), which antioxidants and isoflavones content is high.

Objective: The aim of this study is to evaluate and characterize a new body formulation containing two food by-products extracts.

Materials and methods: Different parameters (such as pH, rheological behavior, color, antioxidant content and microbiological analysis) of a body cream formulation containing by-products (CSMS) and a formulation without extracts (F) were evaluated under a stability study during 180 days at different temperatures. Moreover, the in vitro cell toxicity and the in vivo skin safety and protective effects were also assessed.

Results: Formulation showed stable physical properties and antioxidant activity during 180 days of storage. In vitro toxicity was screened in two skin cell lines (fibroblasts and keratinocytes) and any toxicity was reported. The in vivo test carried out showed that, with respect to irritant effects, CSMS formulation can be regarded as safe for topical application and the skin hydratation improved after 30 days of its use. Also, considering the consumer acceptance, more than 90% of volunteers classified it as very pleasant.

Conclusions: CSMS formulation is stable and safe for topical use as no adverse and/or side effects were observed during the application period of testing, improving skin protective properties.     

Film-Coated Enteric Tablet Formulation of Ketorolac Tromethamine

Abstract

A great majority of polymers used for pharmaceutical film-coating purposes have been derivatives of cellulose or methacrylate copolymers (Eudragit series) in most recent studies. The type and frequency of the ester substituents in the chemical structure of these polymers determines their water permeability and pH-solubility characteristics; therefore, different members of the series may be employed for taste-masking or as enteric-coating agents or dissolution rate-controlling membranes in sustained-release dosage forms. Ketorolac tromethamine (KT) is a non-steroidal drug with potent analgesic and anti-inflammatory activity and is absorbed rapidly (T_max < 1.0 hr) with an efficiency of > 87% following oral and intramuscular administration. The most frequent adverse effects occurring with KT are gastrointestinal disturbances such as peptic ulceration and gastrointestinal bleeding. For this reason, enteric-coated film tablets of KT were prepared in this study by the spray technique. Eudragit S-100 and L-100 were selected as coating materials. Polyethylene glycol (PEG) 4000 was used as a plastifying agent. Core tablets of KT were prepared by the direct compression technique. Tablet specifications were determined and evaluated statistically.     

A Study of the Effects of Sucrose Concentration,Lacquer Concentration and Coating Time on the Formulation of Stable and Effective Carbenicillin Indanyl Sodium Microcapsules

Abstract

Carbenicillin indanyl sodium, commonly known as Geocillin (GC), is an orally effective derivative of carbenicillin employed in the treatment of gram negative infections of the urinary tract. GC exhibits an extremely bitter taste which affects patient compliance upon oral dosing (1). A novel coating approach allows Geocillin to be prepared as a suspension for oral administration. GC is available only as a tablet.

Eudragit E100^R [EE] is a tasteless, acid soluble cationic polymer. Encapsulation of GC with [EE] inhibited its release in the mouth, thus overcoming its bitter taste. Dissolution studies were carried out in simulated gastric fluid and simulated intestinal fluid. Three factors, viz. sucrose concentration, lacquer concentration and coating time were evaluated to arrive at an optimally acceptable formulation.

The formulation containing GC and sucrose in the ratio of 1:3, suspension coated using a 5% w/w lacquer solution for 40 mins. yielded taste free microcapsules with optimal release characteristics.     

Development of novel pH-sensitive nanoparticles loaded hydrogel for transdermal drug delivery

Objective: Difference of pH that exists between the skin surface and blood circulation can be exploited for transdermal delivery of drug molecules by loading drug into pH-sensitive polymer. Eudragit S100 (ES100), a pH-sensitive polymer having dissolution profile above pH 7.4, is used in oral, ocular, vaginal and topical delivery of drug molecules. However, pH-sensitive potential of this polymer has not been explored for transdermal delivery. The aim of this research work was to exploit the pH-sensitive potential of ES100 as a nanocarrier for transdermal delivery of model drug, that is, Piroxicam.

Methods: Simple nanoprecipitation technique was employed to prepare the nanoparticles and response surface quadratic model was applied to get an optimized formulation. The prepared nanoparticles were characterized and loaded into Carbopol 934 based hydrogel. In vitro release, ex vivo permeation and accelerated stability studies were carried out on the prepared formulation.

Results: Particles with an average size of 25–40?nm were obtained with an encapsulation efficiency of 88%. Release studies revealed that nanoparticles remained stable at acidic pH while sustained release with no initial burst effect was observed at pH 7.4 from the hydrogel. Permeation of these nanocarriers from hydrogel matrix showed significant permeation of Piroxicam through mice skin.

Conclusion: It can be concluded that ES100 based pH-sensitive nanoparticles have potential to be delivered through transdermal route.