Development and characterization of magnetic hydrogels loaded with greenly synthesized iron-oxide nanoparticles conjugated with cisplatin.

A novel approach was devised to address the challenges in delivering cisplatin (CIS) for lung cancer treatment. This involved the development of a non-invasive hydrogel delivery system, aiming to minimize side effects associated with its administration. Using carbopol 971 (CP) and chitosan (CH) at varying ratios, the hydrogels were prepared and loaded with eco-friendly iron oxide nanoparticles (IONPs) conjugated to CIS. The physical properties, yield, drug loading, and cytotoxicity against lung cancer cell lines (A549) were assessed, along with hydrogel rheological properties and in vitro drug diffusion. Hydrogel A1 that composed of 1:1 of CP:CH hydrogel loaded with 100 mg IONPs and 250 µg CIS demonstrated distinctive properties that indicate its suitability for potential delivery. The loaded greenly synthesized IONPs@CIS exhibited a particle size of 23.0 nm, polydispersity index of 0.47, yield of 71.6%, with 88.28% drug loading. They displayed significant cytotoxicity (61.7%) against lung cancer cell lines (A549), surpassing free CIS cytotoxicity (28.1%). Moreover, they demonstrated shear-thinning behaviour, viscoelastic properties, and Fickian drug release profile over 24 h (flux 2.34 µg/cm2/h, and permeability 0.31 cm/h).

Minoxidil Nanosuspension-Loaded Dissolved Microneedles for Hair Regrowth.

Minoxidil (MIN) is used topically to treat alopecia. However, its low absorption limits its use, warranting a new strategy to enhance its delivery into skin layers. The objective of this study was to evaluate the dermal delivery of MIN by utilizing dissolved microneedles (MNs) loaded with MIN nanosuspension (MIN-NS) for hair regrowth. MIN-NS was prepared by the solvent-antisolvent precipitation technique. The particle size of MIN-NS was 226.7 ± 9.3 nm with a polydispersity index of 0.29 ± 0.17 and a zeta potential of -29.97 ± 1.23 mV. An optimized formulation of MIN-NS was selected, freeze-dried, and loaded into MNs fabricated with sodium carboxymethyl cellulose (Na CMC) polymeric solutions (MIN-NS-loaded MNs). MNs were evaluated for morphology, dissolution rate, skin insertion, drug content, mechanical properties, ex vivo permeation, in vivo, and stability studies. MNs, prepared with 14% Na CMC, were able to withstand a compression force of 32 N for 30 s, penetrate Parafilm M® sheet at a depth of 374-504 µm, and dissolve completely in the skin within 30 min with MIN %recovery of 95.1 ± 6.5%. The release of MIN from MIN-NS-loaded MNs was controlled for 24 h. MIN-NS-loaded MNs were able to maintain their mechanical properties and chemical stability for 4 weeks, when kept at different storage conditions. The in vivo study of the freeze-dried MIN-NS and MIN-NS-loaded MNs proved hair regrowth on rat skin after 11 and 7 days, respectively. These results showed that MIN-NS-loaded MNs could potentially improve the dermal delivery of MIN through the skin to treat alopecia.

Preparation and Evaluation of Polyvinylpyrrolidone Electrospun Nanofiber Patches of Pioglitazone for the Treatment of Atopic Dermatitis.

Nanofibers have many promising biomedical applications. They can be used for designing transdermal and dermal drug delivery systems. This project aimed to prepare and characterize polyvinylpyrrolidone-based nanofibers as a dermal and transdermal drug delivery system using pioglitazone. Pioglitazone is an oral antidiabetic drug. In addition, it can act as an inflammatory process modulator, making it a good candidate for managing different skin inflammatory conditions such as atopic dermatitis, skin ulcers, and diabetic foot wound healing. Several nanofiber formulations were prepared using the electrospinning method at different drug loadings, polyvinylpyrrolidone concentrations, and flow rates. A cast film with the exact composition of selected nanofiber formulations was prepared as a control. Nanofibers were characterized using a scanning electron microscope to calculate the diameter. Fourier-transform infrared spectroscopy, differential scanning calorimetry, thermogravimetric analysis, and powder X-ray diffraction were performed for physical and biochemical characterizations. In vitro release, drug loading efficiency, and swelling studies were performed. Ex vivo permeation studies were performed using Franz diffusion cells with or without applying a solid microneedle roller. Round uniform nanofibers with a smooth surface were obtained. The diameter of nanofibers was affected by the drug loading and polymer concentration. Fourier-transform infrared spectra showed a potential physical interaction between the drug and the polymer. According to X-ray diffraction, pioglitazone existed in an amorphous form in prepared nanofibers, with partial crystallinity in the casted film. Nanofibers showed a higher swelling rate compared to the casted film. The drug dissolution rate for nanofibers was 2.3-folds higher than the casted films. The polymer concentration affected the drug dissolution rate for nanofibers; however, drug loading and flow rate did not affect the drug dissolution rate for nanofibers. The application of solid microneedles slightly enhances the total amount of drug permeation. However, it did not affect the flux of the drug through the separated epidermis layer for pioglitazone. The drug permeation flux in nanofibers was approximately five times higher than the flux of the casted film. It was observed that pioglitazone is highly retained in skin layers. Graphical abstract.

Surface rheological properties alter aerosol formation from mucus mimetic surfaces.

The effects of surface tension and surface viscoelastic properties on the formation of aerosol droplets generated from mucus-like viscoelastic gels (mucus mimetics) during shearing with a high velocity air stream were investigated. Mucus mimetic samples were formulated with similar composition (94% water and 6% dissolved solids, consisting of mucins, proteins, and ions), surface tension (via the addition of surfactant to the mimetic surface) and bulk viscoelastic properties (via crosslinking of mucin macromolecules in the mimetic) to that of native non-diseased tracheal mucus. The surface tension of the mucus mimetic was decreased by spreading one of two surfactants, dipalmitoyl phosphatidylcholine (DPPC) or calf lung surfactant (Infasurf®), on the mimetic surface. Aerosols were generated from the mimetic surfaces during simulated coughing using an enhanced simulated cough machine (ESCM) operating under controlled environmental conditions. The size distribution of aerosol droplets generated during simulated coughing from the surfactant-coated mimetic surfaces was multimodal, while no droplets were generated from the bare mimetic surface due to its high surface viscoelastic properties and high surface tension. The concentration of aerosols generated from the DPPC-coated mimetic was higher than that of the Infasurf®-coated mimetic, even though the surface tension of the two interfaces was the same. The experimental results suggest that a balance of surface elastic behavior and surface viscous behavior is required for the generation of aerosols from the viscoelastic surfaces.

Diclofenac diethylamine nanosystems-loaded bigels for topical delivery: development, rheological characterization, and release studies.

The objective of this study was to develop novel topical drug delivery systems of the nonsteroidal anti-inflammatory drug diclofenac diethylamine (DDEA). Toward this objective, DDEA was loaded into two nanosystems, the oil in water (O/W) nanoemulsion (DDEA-NE) and the gold nanorods (GNR) that were conjugated to DDEA, forming DDEA-GNR. The DDEA-NE and DDEA-GNR were characterized in terms of particle size, zeta potential, morphology, thermodynamic stability, DDEA loading efficiency, and UV-Vis spectroscopy. These nanosystems were then incorporated into the biphasic gel-based formulations (bigels) for topical delivery. The rheological characterization and release studies of the DDEA NE- and DDEA GNR-incorporated bigels were performed and compared to those of DDEA traditional bigel. DDEA-NE exhibited a droplet size 15.2 ± 1.5 nm and zeta potential -0.37 ± 0.06 mV. The particle size of GNR was approximately 66 nm × 17 nm with an aspect ratio of approximately 3.8. The bigels showed composition-dependent viscoelastic properties, which in turn play a vital role in determining the rate and mechanism of DDEA release from the bigels. Bigels showed a controlled-release pattern where 61.6, 91.7, and 50.0% of the drug was released from DDEA traditional bigel, DDEA NE-incorporated bigel, and DDEA GNR-incorporated bigel, respectively, after 24 h. The ex vivo permeation studies showed that the amount of DDEA permeated through excised skin was relatively low, between 2.7% and 18.2%. The results suggested that the incorporation of the nanosystems NE and GNR into bigels can potentially improve the topical delivery of DDEA.

The Effect of Enzymes and Sodium Lauryl Sulfate on the Surface Tension of Dissolution Media: Toward Understanding the Solubility and Dissolution of Carvedilol.

The objective of this work was to study the effect of the physiologically relevant enzymes pepsin, pancreatin, and the synthetic surfactant sodium lauryl sulfate (SLS) on the surface tension of the dissolution media and the solubility and dissolution of the weakly basic drug carvedilol. Compendial dissolution media and buffer solutions that simulate the gastrointestinal fluid, prepared with and without the addition of SLS, were used in this study. The surface tension of the dissolution media; critical micelle concentration (CMC) of SLS in buffer solutions; and size, polydispersity index, and zeta potential of SLS micelles loading carvedilol were determined. The solubility and dissolution of carvedilol were investigated and compared with those of the corresponding media prepared without the addition of pepsin, pancreatin, and SLS. Results showed that the addition of pepsin, pancreatin, and SLS lowered the surface tension of the dissolution media to 54.8, 55.7, and ~ 30 mN/m, respectively. The solubility of carvedilol was significantly enhanced with pepsin and SLS; however, no significant difference was found with pancreatin. The dissolution rate of carvedilol was fast in simulated gastric fluid with and without pepsin. The dissolution was further enhanced in media with pancreatin and SLS. The dissolution data were corroborated with the molar micellar solubilization (X) of SLS, ranging between 0.02 and 3.09. Understanding the effect of pepsin, pancreatin, and SLS on the surface tension of the dissolution media and the solubility and dissolution of poorly soluble drugs can improve our knowledge of the performance of these drugs in vivo.

Gelation and rheological characterization of Carbopol® in simulated gastrointestinal fluid of variable chemical properties.

Carbopol® is a hydrophilic polymer commonly used in the preparation of oral controlled-release matrix tablets. These matrices are subjected to dissolution testing to investigate the rate and mechanism of drug release. The rate of drug release from these matrices is influenced by the viscoelastic properties of the gel layer formed upon hydration and surrounded tablet core. This study evaluates the gelation behavior and rheological characterization of Carbopol® in dispersion media, of varied chemical properties, commonly used in dissolution testing. The rheological properties of Carbopol® polymer underwent gelation were determined using a controlled-stress rheometer. Carbopol® gelation was not found in simulated gastric fluid of low pH (1.2-5.0) and simulated intestinal fluid of pH (5.0-6.5) during fasted (Fa) and fed (Fe) conditions. However, in water and at high pH (6.8-7.8), gelation occurred in phosphate buffers of high buffering capacity (ß). Furthermore, no gelation was found in sodium chloride solutions of different ionic strengths (µ). These results highlight the importance of investigating the gelation behavior and rheological characterization of Carbopol® in dispersion media prior to dissolution testing. These preliminary studies can give an insight on the formation/absence of the gel layer around Carbopol® matrices which is responsible for controlling the release of drugs.

Development of hydrogels, oleogels, and bigels as local drug delivery systems for periodontitis.

Periodontal disease is a chronic inflammation of gum and tissues that surround and support the teeth. Nonsteroidal anti-inflammatory drugs (NSAIDs) can be used in the treatment of periodontitis to ease swelling and inflammation. One approach of treating periodontitis is loading the NSAIDs in local drug delivery systems. Therefore, the objective of this study was to investigate the local delivery of the NSAIDs model drug ibuprofen to treat periodontitis using different types of gel formulations (hydrogel, oleogel, and bigel). Gel formulations were characterized in terms of their rheological properties (flow behavior, viscoelastic, and bioadhesive properties) using a controlled-stress rheometer. The in vitro drug release of ibuprofen from gel formulations was investigated using Franz diffusion cells. Gels exhibited more solid-like (elastic) behavior. The viscosity and viscoelastic properties were in the order of oleogel > bigel > hydrogel, respectively. In bioadhesion study, mucin dispersion/plain ibuprofen-hydrogel mixture showed a frequency-dependent interaction of ΔG' = -31 and ΔG' = + 53 Pa at 1 and 10 rad/s, respectively. A strong positive interaction (ΔG' = + 6000 and +130,667 Pa at 1 and 10 rad/s, respectively) was found in mucin dispersion/plain ibuprofen-oleogel mixture. The extent of the negative interaction increased in mucin dispersion/plain ibuprofen-bigel mixture (ΔG' = -59,000 and -79,375 Pa at 1 and 10 rad/s, respectively). After 6 h, ibuprofen release from hydrogel, oleogel, and bigel was 59.5 ± 2.2, 80.6 ± 3.9, and 94.6 ± 3.2%, respectively. Results showed that the rheological and bioadhesive properties and in vitro drug release were influenced by the type of gel formulations.

Physiological parameters of the gastrointestinal fluid impact the dissolution behavior of the BCS class IIa drug valsartan.

The objective of this study was to investigate the effect of the physiological parameters (pH, buffer capacity, and ionic strength) of the gastrointestinal (GI) fluid on the dissolution behavior of the class II weakly acidic (BCS class IIa) drug valsartan. A series of in vitro dissolution studies was carried out on Diovan® immediate release tablets using media that cover the physiological range of pH (1.2-7.8), buffer capacity (0-0.047 M/ΔpH), and ionic strength (0-0.4 mol/L) of the GI fluid during fasted and fed states using the conventional USP II apparatus. Valsartan exhibited pH- and buffer capacity-dependent dissolution behavior, where valsartan release was slow and incomplete in media simulating gastric fluid with low pH, and fast and complete in media simulating intestinal fluid with high pH. In addition, the rate of valsartan release increased with increasing the buffer capacity of the dissolution medium. In water and NaCl solutions, valsartan release was incomplete and the dissolution profiles were similar regardless of the ionic strength of the medium, indicating an ionic strength-independent dissolution behavior. These results highlight the significant effect of the physiological parameters of the GI fluid on the dissolution behavior of BCS class IIa drugs.

Correlation between the viscoelastic properties of the gel layer of swollen HPMC matrix tablets and their in vitro drug release.

Drug release from hydroxypropyl methylcellulose (HPMC) hydrophilic matrix tablets is controlled by drug diffusion through the gel layer of the matrix-forming polymer upon hydration, matrix erosion or combination of diffusion and erosion mechanisms. In this study, the relationship between viscoelastic properties of the gel layer of swollen intact matrix tablets and drug release was investigated. Two sets of quetiapine fumarate (QF) matrix tablets were prepared using the high viscosity grade HPMC K4M at low (70 mg/tablet) and high (170 mg/tablet) polymer concentrations. Viscoelastic studies using a controlled stress rheometer were performed on swollen matrices following hydration in the dissolution medium for predetermined time intervals. The gel layer of swollen tablets exhibited predominantly elastic behavior. Results from the in vitro release study showed that drug release was strongly influenced by the viscoelastic properties of the gel layer of K4M tablets, which was further corroborated by results from water uptake studies conducted on intact tablets. The results provide evidence that the viscoelastic properties of the gel layer can be exploited to guide the selection of an appropriate matrix-forming polymer, to better understand the rate of drug release from matrix tablets in vitro and to develop hydrophilic controlled-release formulations.

Transfer Behavior of the Weakly Acidic BCS Class II Drug Valsartan from the Stomach to the Small Intestine During Fasted and Fed States.

The objective of this study was to investigate the transfer behavior of the weakly acidic BCS class II drug valsartan from the stomach to the small intestine during fasted and fed states. An in vitro transfer model previously introduced by Kostewicz et al. (J Pharm Pharmacol 56(1):43-51, 2004) based on a syringe pump and a USP paddle apparatus was used to determine the concentration profiles of valsartan in the small intestine. Donor phases of simulated gastric fluid during fasted (FaSSGF) and fed (FeSSGF) states were used to predisperse Diovan® tablets (160 mg valsartan). The initial concentrations of valsartan in FaSSGF and FeSSGF were 6.2 and 91.8%, respectively. Valsartan dispersions were then transferred to acceptor phases that simulate intestinal fluid and cover the physiological properties (pH, buffer capacity, and ionic strength) of the gastrointestinal fluid at a flow rate of 2 mL/min. The pH measurements were reported at time intervals corresponded to those of the transfer experiments to investigate the effect of percent dissolved of valsartan in the donor phase on lowering the pH of the acceptor phases. The f2 similarity test was used to compare the concentration profiles in the acceptor phases. In fasted state, the concentration of valsartan in the acceptor phases ranged between 33.1 and 89.4% after 240 min. Whereas in fed state, valsartan was fully dissolved in all acceptor phases within a range of 94.5-104.9% after 240 min. Therefore, the transfer model provides a useful screen for the concentrations of valsartan in the small intestine during fasted and fed states.

Formulation and evaluation of diclofenac controlled release matrix tablets made of HPMC and Poloxamer 188 polymer: An assessment on mechanism of drug release.

In this study, hydrophilic hydroxypropyl methylcellulose matrices with various concentrations of Poloxamer 188 were used in the development of oral controlled release tablets containing diclofenac sodium. Four formulations of hydrophilic matrix tablets containing 16.7% w/w HPMC and 0, 6.7, 16.7 and 25.0% w/w Poloxamer 188, respectively, were developed. Tablets were prepared by direct compression and characterized for diameter, hardness, thickness, weight and uniformity of content. The influence of various blends of hydroxypropyl methylcellulose and Poloxamer 188 on the in vitro dissolution profile and mechanism of drug release of was investigated. In the four formulations, the rate of drug release decreased with increasing the concentration of Poloxamer 188 at the initial dissolution stages due to the increase in the apparent viscosity of the gel diffusion layer. However, in the late dissolution stages, the rate of drug release increased with increasing Poloxamer 188 concentration due to the increase in wettability and dissolution of the matrix. The kinetic of drug release from the tablets followed non-Fickian mechanism, as predicted by Korsmeyer-Peppas model, which involves diffusion through the gel layer and erosion of the matrix system.

The effect of pH, buffer capacity and ionic strength on quetiapine fumarate release from matrix tablets prepared using two different polymeric blends.

The objective of this study was to investigate the effect of the different physiological parameters of the gastrointestinal (GI) fluid (pH, buffer capacity, and ionic strength) on the in vitro release of the weakly basic BCS class II drug quetiapine fumarate (QF) from two once-a-day matrix tablet formulations (F1 and F2) developed as potential generic equivalents to Seroquel® XR. F1 tablets were prepared using blends of high and low viscosity grades of hydroxypropyl methylcellulose (HPMC K4M and K100LV, respectively), while F2 tablets were prepared from HPMC K4M and PEGylated glyceryl behenate (Compritol® HD5 ATO). The two formulations attained release profiles of QF over 24 h similar to that of Seroquel® XR using the dissolution medium published by the Food and Drug Administration (FDA). A series of solubility and in vitro dissolution studies was then carried out using media that simulate the gastric and intestinal fluids and cover the physiological pH, buffer capacity and ionic strength range of the GIT. Solubility studies revealed that QF exhibits a typical weak base pH-dependent solubility profile and that the solubility of QF increases with increasing the buffer capacity and ionic strength of the media. The release profiles of QF from F1, F2 and Seroquel® XR tablets were found to be influenced by the pH, buffer capacity and ionic strength of the dissolution media to varying degrees. Results highlight the importance of studying the physiological variables along the GIT in designing controlled release formulations for more predictive in vitro-in vivo correlations.

Nanoemulsion-based gel formulation of diclofenac diethylamine: design, optimization, rheological behavior and in vitro diffusion studies.

Chronic oral administration of the non-steroidal anti-inflammatory drug, diclofenac diethylamine (DDEA), is often associated with gastrointestinal ulcers and bleeding. As an alternative to oral administration, a nanoemulsion-based gel (NE gel) formulation of DDEA was developed for topical administration. An optimized formulation for the o/w nanoemulsion of oil, surfactant and cosurfactant was selected based on nanoemulsion mean droplet size, clarity, stability, and flowability, and incorporated into the gelling agent Carbopol® 971P. Rheological studies of the DDEA NE gel were conducted and compared to those of conventional DDEA gel and emulgel. The three gels exhibited an elastic behavior, where G' dominated G″ at all frequencies, indicating the formation of strong gels. NE gel exhibited higher G' values than conventional gel and emulgel, which indicated the formation of a stronger gel network. Strat-M® membrane, a synthetic membrane with diffusion characteristics that are well correlated to human skin, was used for the in vitro diffusion studies. The release of DDEA from conventional gel, emulgel and NE gel showed a controlled release pattern over 12 h, which was consistent with the rheological properties of the gels. DDEA release kinetics from the three gels followed super case II transport as fitted by Korsmeyer-Peppas model.

pH-Dependent Solubility and Dissolution Behavior of Carvedilol--Case Example of a Weakly Basic BCS Class II Drug.

The objective of this study was to investigate the pH-dependent solubility and dissolution of weakly basic Biopharmaceutical Classification Systems (BCS) class II drugs, characterized by low solubility and high permeability, using carvedilol, a weak base with a pK a value of 7.8, as a model drug. A series of solubility and in vitro dissolution studies was carried out using media that simulate the gastric and intestinal fluids and cover the physiological pH range of the GI from 1.2 to 7.8. The effect of ionic strength, buffer capacity, and buffer species of the dissolution media on the solubility and dissolution behavior of carvedilol was also investigated. The study revealed that carvedilol exhibited a typical weak base pH-dependent solubility profile with a high solubility at low pH (545.1-2591.4 µg/mL within the pH range 1.2-5.0) and low solubility at high pH (5.8-51.9 µg/mL within the pH range 6.5-7.8). The dissolution behavior of carvedilol was consistent with the solubility results, where carvedilol release was complete (95.8-98.2% released within 60 min) in media simulating the gastric fluid (pH 1.2-5.0) and relatively low (15.9-86.2% released within 240 min) in media simulating the intestinal fluid (pH 6.5-7.8). It was found that the buffer species of the dissolution media may influence the solubility and consequently the percentage of carvedilol released by forming carvedilol salts of varying solubilities. Carvedilol solubility and dissolution decreased with increasing ionic strength, while lowering the buffer capacity resulted in a decrease in carvedilol solubility and dissolution rate.

Factor structure and reliability of the Arabic adaptation of the Hypomania Check List-32, second revision (HCL-32-R2).

OBJECTIVE: To assess the psychometric properties of the Arabic adaptation of the Hypomania-Check-List 32-item, second revision (HCL-32-R2) for the detection of bipolarity in major depressive disorder (MDD) inpatients suffering a current major depressive episode (MDE). METHOD: The "Bipolar Disorders: Improving Diagnosis, Guidance, and Education" Arabic module of the HCL-32-R2 was administered to mother-tongue Arabic MDE inpatients between March 2013 and October 2014. Diagnostic and Statistical Manual Fourth edition (DSM-IV) diagnoses were made adopting the mini-international neuropsychiatric interview, using bipolar disorder (BD) patients as controls. RESULTS: In our sample (n=500, of whom, BD-I=329; BD-II=70; MDD=101), using a cut-off of 17 allowed the HCL-32-R2 to discriminate DSM-IV-defined MDD patients between "true unipolar" (HCL-32-R2(-)) and "sub-threshold bipolar depression" (HCL-32-R2(+)) with sensitivity=82% and specificity=77%. Area under the curve was .883; positive and negative predictive values were 93.44% and 73.23% respectively. Owing to clinical interpretability considerations and consistency with previous adaptations of the HCL-32, a two-factor solution (F1="hyperactive/elated" vs. F2="irritable/distractible/impulsive") was preferred using exploratory and confirmatory factors analyses. Item n.33 ("I gamble more") and n.34 ("I eat more") introduced in the R2 version of the HCL-32 loaded onto F1, though very slightly. Cronbach's alphas were F1=.86 and F2=.60. LIMITATIONS: No cross-validation with any additional validated screening tool. Inpatients only sample; recall bias; no systematic evaluation of eventual medical/psychiatric comorbidities, current/lifetime pharmacological history, or record of severity of current MDE. CONCLUSIONS: In our sample, the HCL-32 fairly discriminated between MDD and BD-I but not BD-II, therefore soliciting for replication studies for use in Arabic-speaking depressed inpatients.

Breaking boundaries: the advancements in transdermal delivery of antibiotics.

Transdermal drug delivery systems (TDDS) for antibiotics have seen significant advances in recent years that aimed to improve the efficacy and safety of these drugs. TDDS offer many advantages over other conventional delivery systems such as non-invasiveness, controlled-release pattern, avoidance of first-pass metabolism. The objective of this review is to provide an overview on the recent advances in the TDDS of different groups of antibiotics including ß-lactams, tetracyclines, macrolides, and lincosamides, utilized for their effective delivery through the skin and to explore the challenges associated with this field. The majority of antibiotics do not have favorable properties for passive transdermal delivery. Thus, novel strategies have been employed to improve the delivery of antibiotics through the skin, such as the use of nanotechnology (nanoparticles, solid-lipid nanoparticles, nanoemulsions, vesicular carriers, and liposomes) or the physical enhancement techniques like microneedles and ultrasound. In conclusion, the transdermal delivery systems could be a promising method for delivering antibiotics that have the potential to improve patient outcomes and enhance the efficacy of drugs. Further research and development are still needed to explore the potential of delivering more antibiotic drugs by using various transdermal drug delivery approaches.

Design of colon-targeted drug delivery of dexamethasone: Formulation and in vitro characterization of solid dispersions.

Colon-targeted drug delivery continues to generate increasing attention for its prospects in treating inflammatory bowel disease (IBD). This study aimed to develop and evaluate colon-targeted solid dispersions of dexamethasone (DEX-SDs) in vitro to reduce its systemic exposure. This would ultimately improve the therapeutic efficacy of DEX while minimizing its adverse effects. Different DEX-SDs formulations were prepared utilizing Eudragit S100 (EU S100) and a combination of hydroxypropyl methyl cellulose (HPMC) and EU S100 to tune its drug release profile suitable for colonic delivery. The fabricated formulations were extensively characterized via Attenuated Total Reflectance - Fourier Transform Infrared Spectroscopy (ATR-FTIR), differential scanning calorimetry (DSC), powder X-ray diffraction (PXRD), and polarized light microscopy (PLM). The different characterization techniques strongly suggest preparing solid solution-type solid dispersions of DEX with the other polymers (DEX-SDs). In addition, the in vitro dissolution of DEX-SDs was evaluated using two dissolution media (pH 1.2 and 7.4). The in vitro release of DEX-SDs was low in the acidic media and higher and sustained in the basic medium, leading to the conclusion that the developed DEX-SDs may represent an effective technology can overcome challenges related to poor drug solubility and bioavailability.

Transdermal Delivery System of Doxycycline-Loaded Niosomal Gels: Toward Enhancing Doxycycline Stability.

Doxycycline (DOX) is an antimicrobial agent that is susceptible to photosensitivity and thermal degradation. It addition, it causes gastrointestinal side effects when taken orally. Therefore, the development of alternative formulations is necessary to improve drug stability and promote patient compliance. The aim of the present study was to encapsulate DOX in niosomes as a nanocarrier to deliver DOX transdermally and enhance its stability in the formulation. DOX niosomes were prepared using nonionic surfactants, cholesterol, and dihexadecyl phosphate (DCP). After that, niosomes were characterized in terms of practical size (PS), zeta potential (ZP), morphology, and entrapment efficacy (EE%). DOX niosomal gels were then prepared using Carbopol and penetration enhancers (poly(ethylene glycol) 400 (PEG 400) and propylene glycol (PG)). The flux of DOX from the optimized formula was 322.86 µg/cm2/h over 5 h, which equates to 71.2% of DOX. Furthermore, neither the DOX niosomal gel (D3) nor the comparable blank niosomal gel had a negative influence on human dermal fibroblast (HDF) cells. The findings of the antimicrobial effectiveness of DOX niosomes indicated that the niosomal formulation improved the antibacterial activity of DOX against E. coli. Permeation studies demonstrated significantly higher DOX permeation when the niosomal gel was applied to rat skin, compared to the conventional gel. Permeability parameters such as flux and the permeability coefficient increased more than 10-fold using the niosomal gels compared with those of conventional gels. In conclusion, a new niosomal gel formulation could serve as an effective alternative for the commercially available form of DOX.

Topical gel formulations as potential dermal delivery carriers for green-synthesized zinc oxide nanoparticles.

This study aimed to incorporate green-synthesized zinc oxide nanoparticles (ZnO NPs), functionalized with polyethylene glycol (PEG) and linked to doxorubicin (DOX), into various topical gel formulations (hydrogel, oleogel, and bigel) to enhance their dermal delivery. The ZnO NPs were produced using the aqueous extract of the root hair of Phoenix dactylifera. The optimized green-synthesized ZnO NPs, PEGylated and conjugated to DOX, demonstrated a particle size below 100 nm, low polydispersity index, and zeta potential between - 11 and - 19 mV. The UV-Vis spectroscopy analysis confirmed characteristic absorption peaks at 351 and 545 nm for ZnO and DOX, respectively. The transmission electron microscope (TEM) images revealed well-dispersed spherical nanoparticles without aggregation. Additionally, ZnO NPs-loaded gels exhibited uniformity, cohesion, no phase separation, pseudoplastic flow, and viscoelastic properties. The in vitro release studies showed that DOX-PEG-ZnO NPs hydrogel released 99.5% of DOX after 5 h of starting the release. Moreover, the penetration of DOX-PEG-ZnO NPs through excised rat skin was visualized by TEM. In conclusion, the hydrogel formulation containing green-synthesized DOX-PEG-ZnO NPs holds great promise for dermal administration in skin cancer treatment. Furthermore, the release rate and skin penetration of DOX from gels were varied based on the type of gel matrix and corroborated with their corresponding rheological properties.