Development, optimization and in vitro evaluation of alginate mucoadhesive microspheres of carvedilol for nasal delivery

Intranasal Delivery of Carvedilol- and Quercetin-Encapsulated Cationic Nanoliposomes for Cardiovascular Targeting: Formulation and In Vitro and Ex Vivo Studies

Carvedilol (CVD), an adrenoreceptor blocker, is a hydrophobic Biopharmaceutics Classification System class II drug with poor oral bioavailability due to which frequent dosing is essential to attain pharmacological effects. Quercetin (QC), a polyphenolic compound, is a potent natural antioxidant, but its oral dosing is restricted due to poor aqueous solubility and low oral bioavailability. To overcome the common limitations of both drugs and to attain synergistic cardioprotective effects, we formulated CVD- and QC-encapsulated cationic nanoliposomes (NLPs) in situ gel (CVD/QC-L.O.F.) for intranasal administration. We designed CVD- and QC-loaded cationic nanoliposomal (NLPs) in situ gel (CVD/QC-L.O.F.) for intranasal administration. In vitro drug release studies of CVD/QC-L.O.F. (16.25%) exhibited 18.78 ± 0.57% of QC release and 91.38 ± 0.93% of CVD release for 120 h. Ex vivo nasal permeation studies of CVD/QC-L.O.F. demonstrated better permeation of QC (within 96 h), i.e., 75.09% compared to in vitro drug release, whereas CVD permeates within 48 h, indicating the better interaction between cationic NLPs and the negatively charged biological membrane. The developed nasal gel showed a sufficient mucoadhesive property, good spreadability, higher firmness, consistency, and cohesiveness, indicating suitability for membrane application and intranasal administration. CVD-NLPs, QC-NLPs, and CVD/QC-NLPs were evaluated for in vitro cytotoxicity, in vitro ROS-induced cell viability assessment, and a cellular uptake study using H9c2 rat cardiomyocytes. The highest in vitro cellular uptake of CVD/QC-cationic NLPs by H9c2 cells implies the benefit of QC loading within the CVD nanoliposomal carrier system and gives evidence for better interaction of NLPs carrying positive charges with the negatively charged biological cells. The in vitro H2O2-induced oxidative stress cell viability assessment of H9c2 cells established the intracellular antioxidant activity and cardioprotective effect of CVD/QC-cationic NLPs with low cytotoxicity. These findings suggest the potential of cationic NLPs as a suitable drug delivery carrier for CVD and QC combination for the intranasal route in the treatment of various cardiovascular diseases like hypertension, angina pectoris, etc. and for treating neurodegenerative disorders.

Spray-Dried Mucoadhesive Re-dispersible Gargle of Chlorhexidine for Improved Response Against Throat Infection: Formulation Development, In Vitro and In Vivo Evaluation

Drug delivery to the buccal mucosa is one of the most convenient ways to treat common mouth problems. Here, we propose a spray-dried re-dispersible mucoadhesive controlled release gargle formulation to improve the efficacy of chlorhexidine. The present investigation portrays an approach to get stable and free-flowing spray-dried porous aggregates of chlorhexidine-loaded sodium alginate nanoparticles. The ionic gelation technique aided with the chlorhexidine's positive surface charge-based crosslinking, followed by spray drying of the nanoparticle's dispersion in the presence of lactose- and leucine-yielded nano-aggregates with good flow properties and with a size range of about 120-350 nm. Provided with the high entrapment efficiency (87%), the particles showed sustained drug release behaviors over a duration of 10 h, where 87% of the released drug got permeated within 12 h. The antimicrobial activity of the prepared formulation was tested on S. aureus, provided with a higher zone of growth inhibition than the marketed formulation. Aided with an appropriate mucoadhesive strength, this product exhibited extended retention of nanoparticles in the throat region, as shown by in vivo imaging results. In conclusion, the technology, provided with high drug retention and extended effect, could be a potential candidate for treating several types of throat infections.

A Review of Natural Polysaccharides: Sources, Characteristics, Properties, Food, and Pharmaceutical Applications

Natural polysaccharides, which are described in this study, are some of the most extensively used biopolymers in food, pharmaceutical, and medical applications, because they are renewable and have a high level of biocompatibility and biodegradability. The fundamental understanding required to properly exploit polysaccharides potential in the biocomposite, nanoconjugate, and pharmaceutical industries depends on detailed research of these molecules. Polysaccharides are preferred over other polymers because of their biocompatibility, bioactivity, homogeneity, and bioadhesive properties. Natural polysaccharides have also been discovered to have excellent rheological and biomucoadhesive properties, which may be used to design and create a variety of useful and cost-effective drug delivery systems. Polysaccharide-based composites derived from natural sources have been widely exploited due to their multifunctional properties, particularly in drug delivery systems and biomedical applications. These materials have achieved global attention and are in great demand because to their biochemical properties, which mimic both human and animal cells. Although synthetic polymers account for a substantial amount of organic chemistry, natural polymers play a vital role in a range of industries, including biomedical, pharmaceutical, and construction. As a consequence, the current study will provide information on natural polymers, their biological uses, and food and pharmaceutical applications.

Contemporary Aspects of Designing Marine Polysaccharide Microparticles as Drug Carriers for Biomedical Application

The main goal of modern pharmaceutical technology is to create new drug formulations that are safer and more effective. These formulations should allow targeted drug delivery, improved drug stability and bioavailability, fewer side effects, and reduced drug toxicity. One successful approach for achieving these objectives is using polymer microcarriers for drug delivery. They are effective for treating various diseases through different administration routes. When creating pharmaceutical systems, choosing the right drug carrier is crucial. Biomaterials have become increasingly popular over the past few decades due to their lack of toxicity, renewable sources, and affordability. Marine polysaccharides, in particular, have been widely used as substitutes for synthetic polymers in drug carrier applications. Their inherent properties, such as biodegradability and biocompatibility, make marine polysaccharide-based microcarriers a prospective platform for developing drug delivery systems. This review paper explores the principles of microparticle design using marine polysaccharides as drug carriers. By reviewing the current literature, the paper highlights the challenges of formulating polymer microparticles, and proposes various technological solutions. It also outlines future perspectives for developing marine polysaccharides as drug microcarriers.

Preparation and Characteristics of Alginate Microparticles for Food, Pharmaceutical and Cosmetic Applications

Alginates are the most widely used natural polymers in the pharmaceutical, food and cosmetic industries. Usually, they are applied as a thickening, gel-forming and stabilizing agent. Moreover, the alginate-based formulations such as matrices, membranes, nanospheres or microcapsules are often used as delivery systems. Alginate microparticles (AMP) are biocompatible, biodegradable and nontoxic carriers, applied to encapsulate hydrophilic active substances, including probiotics. Here, we report the methods most frequently used for AMP production and encapsulation of different actives. The technological parameters important in the process of AMP preparation, such as alginate concentration, the type and concentration of other reagents (cross-linking agents, oils, emulsifiers and pH regulators), agitation speed or cross-linking time, are reviewed. Furthermore, the advantages and disadvantages of alginate microparticles as delivery systems are discussed, and an overview of the active ingredients enclosed in the alginate carriers are presented.

Investigation of Alogliptin-Loaded In Situ Gel Implants by 23 Factorial Design with Glycemic Assessment in Rats

The aim of the study was to design injectable long-acting poly (lactide-co-glycolide) (PLGA)-based in situ gel implants (ISGI) loaded with the anti-diabetic alogliptin. Providing sustained therapeutic exposures and improving the pharmacological responses of alogliptin were targeted for achieving reduced dosing frequency and enhanced treatment outputs. In the preliminary study, physicochemical characteristics of different solvents utilized in ISGI preparation were studied to select a proper solvent possessing satisfactory solubilization capacity, viscosity, water miscibility, and affinity to PLGA. Further, an optimization technique using a 2³ factorial design was followed. The blood glucose levels of diabetic rats after a single injection with the optimized formulation were compared with those who received daily oral alogliptin. N-methyl-2-pyrrolidone (NMP) and dimethyl sulfoxide (DMSO), as highly water-miscible and low viscous solvents, demonstrated their effectiveness in successful ISGI preparation and controlling the burst alogliptin release. The impact of increasing lactide concentration and PLGA amount on reducing the burst and cumulative alogliptin release was represented. The optimized formulation comprising 312.5 mg of PLGA (65:35) and DMSO manifested a remarkable decrease in the rats’ blood glucose levels throughout the study period in comparison to that of oral alogliptin solution. Meanwhile, long-acting alogliptin-loaded ISGI systems demonstrated their feasibility for treating type 2 diabetes with frequent dosage reduction and patient compliance enhancement.

Microencapsulation of Lactobacillus plantarum with enzymatic hydrolysate of soybean protein isolate for improved acid resistance and gastrointestinal survival in vitro

This study aimed to improve the acid resistance effect of Lactobacillus plantarum through microencapsulation with enzymatic hydrolysate of soybean protein isolate (EHSPI) and modified phospholipid. Response surface methodology was adopted to establish the optimal microencapsulation technology of L. plantarum, while coating characters were evaluated. Through response surface methodology, the optimal conditions were obtained as follows based on microencapsulation efficiency: the ratio of bacteria/EHSPI 1:1.83, EHSPI content 4.01%, modified phospholipid content 11.41%. The results of digestion in vitro showed that after passing through the simulated gastric fluid (SGF), the L. plantarum was released and reached 3.55 × 108 CFU/mL in the simulated intestinal fluid. Meanwhile, the surviving bacteria number of control significantly decreased to 2.63 × 104 CFU/mL (P < 0.05) at 120 min in SGF. In sum, the acid resistance and survival of L. plantarum were improved in SGF in vitro, through the microencapsulation technology based on EHSPI.

Engineered nasal dry powder for the encapsulation of bioactive compounds

In this review, we present the potential of nasal dry powders to deliver stable bioactive compounds and their manufacture using spray-drying (SD) techniques to achieve encapsulation. We also review currently approved and experimental excipients used for powder manufacturing for specific target drugs. Polymers, sugars, and amino acids are recommended for specific actions, such as mucoadhesive interactions, to increase residence time on the nasal mucosa; for example, high-molecular weight polymers, such as hydroxypropyl methylcellulose, or mannitol, which protect the bioactive compounds, increase their stability, and enhance drug absorption in the nasal mucosa; and leucine, which promotes particle formation and improves aerosol performance. Teaser: XXXX.

Recent advances in microencapsulation of drugs for veterinary applications

Microencapsulation is a process where very minute droplets or particles of solid or liquid or gas are trapped with a polymer to isolate the internal core material from external environmental hazards. Microencapsulation is applied mostly for flavor masking, fortification, and sustained and control release. It improves palatability, absorption, and bioavailability of drugs with good conformity. Microencapsulation has been widely studied in numerous drug delivery systems for human health. The application of microcapsules in the veterinary pharmaceutical sciences is increasing day by day. The treatment systems for humans and animals are likely to be similar, but more complex in the veterinary field due to the diversity of the species, breeds, body size, biotransformation rate, and other factors associated with animal physiology. Commercially viable, economically profitable, and therapeutically effective microencapsulated vaccine, anthelmintic, antibacterial, and other therapeutics have a great demand for livestock and poultry production. Nowadays, researchers emphasize the controlled and sustained-release dosage form of drugs in the veterinary field. This paper has highlighted the microencapsulation materials, preparation techniques, characteristics, roles, and the application of microcapsules in veterinary medicine.

Formulation, characterization and statistical optimization of enalapril-loaded lipospheres

Lipid-based polymers have been proved efficient drug carriers for overcoming the insufficiencies of conventional formulations. Ceresin wax was employed to improve permeability, oral bioavailability and patient compliance by preparing enalapril (EP)-loaded lipospheres with a simple solvent evaporation method. A Box–Behnken design with the proposed polynomial equations and quadratic model was applied to investigate and statistically validate the collective influence of formulation variables on lipospheres. Spherical smooth-surfaced lipospheres with an average size of 55 μm with excellent micromeritic properties were produced. Differential scanning calorimetry, X-ray diffraction and Fourier transmission infrared spectroscopy findings proved the lack of any possible interaction between formulation components. The zeta potential ranged from −5 to −20 mV, suggesting the significant stability of lipospheres. Responses such as percentage yield (29–68%), entrapment efficiency (21–53%) and drug release (42–93%) were found to be affected greatly by the concentrations of lipids and the surfactant, and the stirring speed. Reduced and sustained EP release from lipospheres may lower treatment cost and enhance hypertensive patients’ compliance.

Alginate Nanoformulation: Influence of Process and Selected Variables

Nanocarriers are defined as structures and devices that are constructed using nanomaterials which add functionality to the encapsulants. Being small in size and having a customized surface, improved solubility and multi-functionality, it is envisaged that nanoparticles will continue to create new biomedical applications owing to their stability, solubility, and bioavailability, as well as controlled release of drugs. The type and physiochemical as well as morphological attributes of nanoparticles influence their interaction with living cells and determine the route of administration, clearance, as well as related toxic effects. Over the past decades, biodegradable polymers such as polysaccharides have drowned a great deal of attention in pharmaceutical industry with respect to designing of drug delivery systems. On this note, biodegradable polymeric nanocarrier is deemed to control the release of the drug, stabilize labile molecules from degradation and site-specific drug targeting, with the main aim of reducing the dosing frequency and prolonging the therapeutic outcomes. Thus, it is essential to select the appropriate biopolymer material, e.g., sodium alginate to formulate nanoparticles for controlled drug delivery. Alginate has attracted considerable interest in pharmaceutical and biomedical applications as a matrix material of nanocarriers due to its inherent biological properties, including good biocompatibility and biodegradability. Various techniques have been adopted to synthesize alginate nanoparticles in order to introduce more rational, coherent, efficient and cost-effective properties. This review highlights the most used and recent manufacturing techniques of alginate-based nanoparticulate delivery system, including emulsification/gelation complexation, layer-by-layer, spray drying, electrospray and electrospinning methods. Besides, the effects of the main processing and formulation parameters on alginate nanoparticles are also summarized.

Floating Microspheres of Enalapril Maleate as a Developed Controlled Release Dosage Form: Investigation of the Effect of an Ionotropic Gelation Technique

OBJECTIVES

The purpose of this study was to provide a control drug delivery system through a newly approved work to enhance the absorption and bioavailability of enalapril maleate loaded floating microspheres by ionotropic gelation technique using a hydrophilic carrier.

MATERIALS AND METHODS

Eleven developed formulations of floating microspheres were prepared by ionotropic gelation using different concentrations of sodium alginate, iota-carrageenan, sodium bicarbonate, calcium chloride, and the drug. These microspheres were characterized using a diversity of parameters like micrometric properties, percentage yield, entrapment efficiency, in vitro buoyancy, in vitro drug release, and kinetics of drug release. The optimum formula was evaluated and identified for drug-excipients compatibility using fourier transform-infrared spectroscopy (FT-IR), surface morphology, powder X-ray diffraction (XRD), and differential scanning calorimetry (DSC).

RESULTS

From the results, F4 was selected as the optimum formula since it provides a faster and premium release of drug from the matrix (91.4%). Kinetics of drug release was found to depend on both diffusion and erosion mechanisms, as the correlation coefficient (R2) was best fitted with Korsmeyer's model and the release exponent (n) was shown to be between 0.43 and 0.84. Scanning electron microscopy images demonstrated spherical, discrete, and freely flowing microspheres with a particle size of 199.4±0.04 μm. Optimum buoyancy properties, percentage yield, and drug entrapment efficiency were achieved. FT-IR showed no interaction between enalapril and the polymers. DSC and XRD showed the miscibility of the drug with the polymers while maintaining the stable crystalline properties of enalapril loaded in the prepared microspheres.

CONCLUSION

The developed floating microspheres of enalapril maleate can be considered a promising controlled drug delivery system, thereby improving patient compliance.

Nasal delivery of nanosuspension-based mucoadhesive formulation with improved bioavailability of loratadine: Preparation, characterization, and in vivo evaluation

The unique requirements of poorly water-soluble drug delivery have driven a great deal of research into new formulations and routes of administration. This study investigates the use of nanosuspensions for solubility enhancement and drug delivery. Simple methods were used to prepare nasal formulations of loratadine based on nanosuspension pre-dispersion with sodium hyaluronate as a mucoadhesive agent. The nanosuspension was prepared by antisolvent precipitation method followed by ultrasonication and characterized for particle size, polydispersity index, zeta potential, morphology, and structure. Moreover, the nasal formulations were characterized for drug loading, pH, particle size, viscosity, bioadhesive viscosity parameter, and were evaluated for in vitro dissolution and diffusion, in addition to in vivo studies in a rat model. Loratadine nanosuspension displayed a particle size of 311 nm, a polydispersity index of 0.16, and zeta potential of -22.05 mV. The nanosuspension preserved the crystalline status of the raw drug. The addition of sodium hyaluronate exhibited an increase in the mean particle size and zeta potential of the nanoparticles. The nasal formulations showed enhanced bioadhesive properties compared to the unprocessed loratadine in the reference samples. The nanosuspension based-formulation that contained 5 mg mL^-1 sodium hyaluronate and 2.5 mg mL^-1 loratadine (NF4) showed a significant enhancement of flux and permeability coefficient through a synthetic membrane. NF4 exhibited 24.73 µg cm^-2 h^-1 and 0.082 cm h^-1, while the reference sample showed 1.49 µg cm^-2 h^-1 and 0.017 cm h^-1, for the flux and the permeability coefficient, respectively. Nasal administration of NF4 showed a bioavailability of 5.54-fold relative to the oral administration. The results obtained in this study indicate the potential of the nasal route and the nanosuspension for loratadine delivery. The relative bioavailability of NF4 was 1.84-fold compared to unprocessed loratadine in the reference sample. Therefore, the nanosized loratadine could be suggested as a practical and simple nanosystem for the intranasal delivery with improved bioavailability.

Composite Central Face Design-An Approach to Achieve Efficient Alginate Microcarriers

Microparticulated drug delivery systems have been used as promising encapsulation systems for protecting drugs for in vitro and in vivo applications, enhancing its stability, providing an increased surface to volume ratio, reducing adverse effects, and hence an improvement in bioavailability. Among the studied microparticles, there is a rising interest in the research of alginate microparticles for pharmaceutical and biomedical fields confirming its potential to be used as an effective matrix for drug and cell delivery. Moreover, calcium alginate has been one of the most extensively forming microparticles in the presence of divalent cations providing prolonged drug release and suitable mucoadhesive properties. Regarding the above mentioned, in this research work, we intended to produce Ca-alginate micro-vehicles through electrospraying, presenting high encapsulation efficiency (EE%), reduced protein release across the time, reduced swelling effect, and high sphericity coefficient. To quickly achieve these characteristics and to perform an optimal combination among the percentage of alginate and CaCl2, design of Experiments was applied. The obtained model presented to be statistically significant (p-value < 0.05), with a coefficient of determination of 0.9207, 0.9197, 0.9499, and 0.9637 for each output (EE%, release, swelling, and sphericity, respectively). Moreover, the optimal point (4% of alginate and 6.6% of CaCl2) was successfully validated.

Applications of alginate microspheres in therapeutics delivery and cell culture: Past, present and future

Polymers are the backbone of pharmaceutical drug delivery. There are several polymers with varying properties available today for use in different pharmaceutical applications. Alginate is widely used in biomedical research due to its attractive features such as biocompatibility, biodegradability, inertness, low cost, and ease of production and formulation. Encapsulation of therapeutic agents in alginate/alginate complex microspheres protects them from environmental stresses, including the acidic environment in the gastro-intestinal tract (GIT) and enzymatic degradation, and allows targeted and sustained delivery of the agents. Microencapsulation is playing an increasingly important role in drug delivery as evidenced by the recent surge in research articles on the use of alginate in the delivery of small molecules, cells, bacteria, proteins, vaccines, and for tissue engineering applications. Formulation of these alginate microspheres (AMS) are commonly achieved by conventional external gelation method using various instrumental manipulation such as vortexing, homogenization, ultrasonication or spray drying, and each method affects the overall particle characteristics. In this review, an inclusive summary of the currently available methods for the formulation of AMS, its recent use in the encapsulation and delivery of therapeutics, and future outlook will be discussed.

Design of Experiments (DoE) Approach to Optimize the Sustained Release Microparticles of Gefitinib

Background:

Gefitinib (GEF), the kinase inhibitor, is presently available as tablets to be taken orally in high doses of 250-500 mg per day due to its poor solubility. The solubility issues affect not only its onset of action but also the bioavailability. These drawbacks foresight the need to have an alternate dosage form, preferably a sustained release formulation.

Methods:

In the present study, microparticles were prepared by emulsion solvent evaporation using PLGA 50:50 (GEF-PLGA MP). A 32 factorial design was used to optimize the critical quality parameters to the set mean particle size in the range of 7.4±2.5 µm and entrapment efficiency of 80%. SEM microscopy of the prepared microparticles confirmed to have a spherical smooth shape. The GEFPLGA- MPs sustained the release of GEF for 72 hours. The first-order kinetics ruled the mechanism of drug release and was predicted to follow Fickian diffusion.

Result:

Anticancer efficacy was judged by the cytotoxicity studies using the L132 lung cancer cells. MTT assay showed 3-fold enhanced cytotoxicity of GEF loaded microparticles against L132 cells as compared to plain GEF.

Conclusion:

It was concluded that gefitinib can be efficiently loaded into the biodegradable polymer PLGA to provide sustained release of the drug.

Sustained release biodegradable solid lipid microparticles: Formulation, evaluation and statistical optimization by response surface methodology

For preparing nebivolol loaded solid lipid microparticles (SLMs) by the solvent evaporation microencapsulation process from carnauba wax and glyceryl monostearate, central composite design was used to study the impact of independent variables on yield (Y1), entrapment efficiency (Y2) and drug release (Y3). SLMs having a 10-40 μm size range, with good rheological behavior and spherical smooth surfaces, were produced. Fourier transform infrared spectroscopy, differential scanning calorimetry and X-ray diffractometry pointed to compatibility between formulation components and the zeta-potential study confirmed better stability due to the presence of negative charge (-20 to -40 mV). The obtained outcomes for Y1 (29-86 %), Y2 (45-83 %) and Y3 (49-86 %) were analyzed by polynomial equations and the suggested quadratic model were validated. Nebivolol release from SLMs at pH 1.2 and 6.8 was significantly (p < 0.05) affected by lipid concentration. The release mechanism followed Higuchi and zero order models, while n > 0.85 value (Korsmeyer- Peppas) suggested slow erosion along with diffusion. The optimized SLMs have the potential to improve nebivolol oral bioavailability.

Preparation and characterization of beta-glucan particles containing a payload of nanoembedded rifabutin for enhanced targeted delivery to macrophages

β-glucan particles (GP) are polymeric carbohydrates, mainly found as components of cell wall fungi, yeast, bacteria and also in cereals such as barley and oat, and have been recently shown to have application in macrophage-targeted drug delivery. The aim of this study was to prepare and characterize GP containing a large payload of Rifabutin (RB), an anti-tuberculosis drug effective against MDR-TB at lower MIC than Rifampicin. GP were prepared from yeast cells by acidic and alkaline extraction were either spray dried or lyophilized, prior to RB loading and alginate sealing. The FTIR and ¹³C-NMR spectra of the GP confirmed a β-(1→3) linked glucan structure, with a triple-helical conformation. The spray dried GP exhibited better characteristics in terms of uniformity, size range (2.9 to 6.1 µm) and more than 75 % particles were below 3.5 μm. The RP-HPLC analysis of spray dried GP revealed drug entrapment and drug loading up to 81.46 ± 4.9 % and ~40.5 ± 1.9 %, respectively, as compared to those dried by lyophilization. Electron microscopy showed nearly spherical and porous nature of GP, and the presence of drug 'nanoprecipitates' filling the pore spaces. The formulation showed adequate thermal stability for pharmaceutical application. The particles were readily phagocytosed by macrophage(s) within 5 min of exposure. Drug release occurred in a sustained manner via diffusion, as the release kinetics best fit for drug release was obtained using Higuchi's equation. Thus, the spray dried GP-based-formulation technology holds promise for enhanced targeted delivery of anti-TB drug(s) to macrophage within a therapeutic window for the clearance of intracellular bacteria.

Fabrication of an ionic-sensitive in situ gel loaded with resveratrol nanosuspensions intended for direct nose-to-brain delivery

The objective of this study was to fabricate a composite in situ gelling formulation combining nanoparticulates and an ionic-triggered deacetylated gellan gum (DGG) matrix for challenging intranasal drug delivery. The prepared resveratrol nanosuspensions (Res-NSs) were distributed in DGG solutions. Parameters such as the in situ gelation capability, particle size, rheological properties, and texture profiles were used to describe the properties of the in situ gel. Pharmacokinetic and brain-targeting efficiency studies were performed after intranasal and intravenous administration, respectively. Biodistribution and localization using in vivo imaging systems and fluorescence microscopy are also described. The formulation containing 0.6% w/v DGG displayed a favorable gelling ability and the desired viscosity. The rheology results established that the DGG in situ gel possesses the characteristics of shear thinning, thixotropy and yield stress. The results of the textural profile revealed an increase in adhesiveness and viscosity for the in situ gel compared to the DGG solution. In vitro penetration studies followed a Higuchi mathematic model. Pharmacokinetics revealed a 2.88-times increase of bioavailability in the brain by intranasal Res-NSs in situ gel formulation. The drug targeting efficiency (458.2%) and direct transport percentages (78.18%) demonstrated direct delivery via the nose-brain pathway. The distribution and localization further illustrated the existence of direct nose-to-brain transport, bypassing the BBB. In sum, this hybrid in situ gel system is a promising approach for intranasal application in terms of the enhancement of nasal mucosal permeability and increased nasal cavity residence time by a nanotechnology delivery system and in situ gelling technology.

Ion activated in situ gel of gellan gum containing salbutamol sulphate for nasal administration

Nasal delivery is the promising approach for rapid onset of action and avoids the first pass metabolism. The main aim of present study was to develop a novel mucoadhesive in situ gel of salbutamol sulphate using gellan gum and hydroxylpropyl methyl cellulose (HPMC) for nasal administration. The formulations were prepared so as to have gelation at physiological ion content after nasal administration. Developed formulations were evaluated for gelation, viscosity, drug content, in vitro mucoadhesion, in vitro drug release study, ex vivo permeation, and histopathology. Formulations showed pH in the range of nasal cavity and optimum viscosity for nasal administration. The mucoadhesive force depends upon concentration of HPMC and drug release was found to be 97.34% in 11h. The histopathology did not detect any damage during ex vivo permeation studies. Hence, in situ gel system of gellan gum may be a promising approach for nasal delivery of salbutamol sulphate for therapeutic improvement.

Nose-To-Brain Delivery of PLGA-Diazepam Nanoparticles

The objective of the present investigation was to optimize diazepam (Dzp)-loaded poly(lactic-co-glycolic acid) nanoparticles (NP) to achieve delivery in the brain through intranasal administration. Dzp nanoparticles (DNP) were formulated by nanoprecipitation and optimized using Box-Behnken design. The influence of various independent process variables (polymer, surfactant, aqueous to organic (w/o) phase ratio, and drug) on resulting properties of DNP (z-average and drug entrapment) was investigated. Developed DNP showed z-average 148-337 d.nm, polydispersity index 0.04-0.45, drug entrapment 69-92%, and zeta potential in the range of -15 to -29.24 mV. Optimized DNP were further analyzed by differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FTIR), ex-vivo drug release, and in-vitro cytotoxicity. Ex-vivo drug release study via sheep nasal mucosa from DNP showed a controlled release of 64.4% for 24 h. 3-[4,5-Dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) assay performed on Vero cell line showed less toxicity for DNP as compared to Dzp suspension (DS). Gamma scintigraphy and biodistribution study of DNP and DS was performed on Sprague-Dawley rats using technetium-99m-labeled ((99m)Tc) Dzp formulations to investigate the nose-to-brain drug delivery pathway. Brain/blood uptake ratios, drug targeting efficiency, and direct nose-to-brain transport were found to be 1.23-1.45, 258, and 61% for (99m)Tc-DNP (i.n) compared to (99m)Tc-DS (i.n) (0.38-1.06, 125, and 1%). Scintigraphy images showed uptake of Dzp from nose-to-brain, and this observation was in agreement with the biodistribution results. These results suggest that the developed poly(D,L-lactide-co-glycolide) (PLGA) NP could serve as a potential carrier of Dzp for nose-to-brain delivery in outpatient management of status epilepticus.

Preparation and Evaluation of Mucoadhesive Beads/Discs of Alginate and Algino-Pectinate of Piroxicam for Colon-Specific Drug Delivery Via Oral Route

Background:

Objective:

Materials and Methods:

Results:

Conclusions:

Formulation and optimization of polymeric nanoparticles for intranasal delivery of lorazepam using Box-Behnken design: in vitro and in vivo evaluation

The aim of the present study was to optimize lorazepam loaded PLGA nanoparticles (Lzp-PLGA-NPs) by investigating the effect of process variables on the response using Box-Behnken design. Effect of four independent factors, that is, polymer, surfactant, drug, and aqueous/organic ratio, was studied on two dependent responses, that is, z-average and % drug entrapment. Lzp-PLGA-NPs were successfully developed by nanoprecipitation method using PLGA as polymer, poloxamer as surfactant and acetone as organic phase. NPs were characterized for particle size, zeta potential, % drug entrapment, drug release behavior, TEM, and cell viability. Lzp-PLGA-NPs were characterized for drug polymer interaction using FTIR. The developed NPs showed nearly spherical shape with z-average 167–318 d·nm, PDI below 0.441, and −18.4 mV zeta potential with maximum % drug entrapment of 90.1%. In vitro drug release behavior followed Korsmeyer-Peppas model and showed initial burst release of 21.7 ± 1.3% with prolonged drug release of 69.5 ± 0.8% from optimized NPs up to 24 h. In vitro drug release data was found in agreement with ex vivo permeation data through sheep nasal mucosa. In vitro cell viability study on Vero cell line confirmed the safety of optimized NPs. Optimized Lzp-PLGA-NPs were radiolabelled with Technitium-99m for scintigraphy imaging and biodistribution studies in Sprague-Dawley rats to establish nose-to-brain pathway.

Formulation and evaluation of carvedilol microcapsules using Eudragit NE30D and sodium alginate

Inclusion complexes of carvedilol(CR) with hydroxyl propyl beta-cyclodextrin (HPBCD) was prepared using co-grinding technique. Then, the inclusion complex was microencapsulated using combinations of Eudragit NE30D (EU) and sodium alginate (SA) utilizing orifice gelation technique. The formulations were analysed by using Scanning electron microscopy (SEM), Fourier Transform Infrared spectroscopy (FTIR), Differential scanning Calorimetry (DSC) and X-ray diffractometer (XRD) and also evaluated for particle size, encapsulation efficiency, production yield, swelling capacity, mucoadhesive properties, zeta potential and drug release. The microcapsules were smooth and showed no visible cracks and extended drug release of 55.2006% up to 12 hours in phosphate buffer of pH 6.8, showing particle size within the range of 264.5-358.5 µm, and encapsulation efficiency of 99.337±0.0100-66.2753±0.0014%.The in vitro release data of optimized batch of microcapsules were plotted in various kinetic equations to understand the mechanisms and kinetics of drug release, which followed first order kinetics, value of "n" is calculated to be 0.459 and drug release was diffusion controlled. The mice were fed with diet for inducing high blood pressure and the in vivo antihypertensive activity of formulations was carried out administering the optimized formulations and pure drug separately by oral feeding and measured by B.P Monwin IITC Life Science instrument and the results indicated that the bioavailability of carvedilol was increased both in vitro and in vivo with the mucoadhesive polymers showing primary role in retarding the drug release.

Optimization of curcumin nanoemulsion for intranasal delivery using design of experiment and its toxicity assessment

The objective of the study was to optimize curcumin nanoemulsion for intranasal delivery using design of experiment. Box-Behnken design was constructed using oil, surfactant and co-surfactant concentration as independent variables and their affect on response y1 (globule size) and y2 (zeta potential) were studied. The ANOVA test identified the significant factors that affected the responses. For globule size, percentage of oil, surfactant and co-surfactant were identified as significant model terms whereas for zeta potential, oil and co-surfactant were found to be significant. Critical factors affecting the responses were identified using perturbation and contour plots. The derived polynomial equation and contour graph aid in predicting the values of selected independent variables for preparation of optimum nanoemulsion with desired properties. Further, 2(4) factorial design was used to study influence of chitosan on particle size and zeta potential. The formulations were subjected to in vitro cytotoxicity using SK-N-SH cell line and nasal ciliotoxicity studies. The developed formulations did not show any toxicity and were safe for intranasal delivery for brain targeting. In vitro diffusion studies revealed that nanoemulsions had a significantly higher release compared to drug solution. Ex vivo diffusion studies were carried out using sheep nasal mucosa fixed onto Franz diffusion cells. Mucoadhesive nanoemulsion showed higher flux and permeation across sheep nasal mucosa.

Bioavailability enhancement of verapamil HCl via intranasal chitosan microspheres

Chitosan microspheres are potential drug carriers for maximizing nasal residence time, circumventing rapid mucociliary clearance and enhancing nasal absorption. The aim of the present study was to develop and characterize chitosan mucoadhesive microspheres of verapamil hydrochloride (VRP) for intranasal delivery as an alternative to oral VRP which suffers low bioavailability (20%) due to extensive first pass effect. The microspheres were produced using a spray-drying and precipitation techniques and characterized for morphology (scanning electron microscopy), particle size (laser diffraction method), drug entrapment efficiency, thermal behavior (differential scanning calorimetry) and crystallinity (X-ray diffractometric studies) as well as in vitro drug release. Bioavailability of nasal VRP microspheres was studied in rabbits and the results were compared to those obtained after nasal, oral and intravenous administration of VRP solution. Results demonstrated that the microspheres were spherical with size 21-53 μm suitable for nasal deposition. The spray-drying technique was superior over precipitation technique in providing higher VRP entrapment efficiency and smaller burst release followed by a more sustained one over 6h. The bioavailability study demonstrated that the nasal microspheres exhibited a significantly higher bioavailability (58.6%) than nasal solution of VRP (47.8%) and oral VRP solution (13%). In conclusion, the chitosan-based nasal VRP microspheres are promising for enhancing VRP bioavailability by increasing the nasal residence time and avoiding the first-pass metabolism of the drug substance.

The effect of polymer coatings on physicochemical properties of spray-dried liposomes for nasal delivery of BSA

This work describes the development of spray dried polymer coated liposomes composed of soy phosphatidylcholine (SPC) and phospholipid dimyristoyl phosphatidylglycerol (DMPG) coated with alginate, chitosan or trimethyl chitosan (TMC), that are able to penetrate through the nasal mucosa and offer enhanced penetration over uncoated liposomes when delivered as a dry powder. All the liposome formulations, loaded with BSA as model antigen, were spray-dried to obtain powder size and liposome size in a suitable range for nasal delivery. Although coating resulted in some reduction in encapsulation efficiency, levels were still maintained between 60% and 69% and the structural integrity of the entrapped protein and its release characteristics were maintained. Coating with TMC gave the best product characteristics in terms of entrapment efficiency, glass transition (T(g)) and mucoadhesive strength, while penetration of nasal mucosal tissue was very encouraging when these liposomes were administered as dispersions although improved results were observed for the dry powders.

Solid lipid nanoparticles of ondansetron HCl for intranasal delivery: development, optimization and evaluation

The present investigation deals with the development and statistical optimization of solid lipid nanoparticles (SLNs) of ondansetron HCl (OND) for intranasal (i.n.) delivery. SLNs were prepared using the solvent diffusion technique and a 2(3) factorial design. The concentrations of lipid, surfactant and cosurfactant were independent variables in this design, whereas, particle size and entrapment efficiency (EE) were dependent variables. The particle size of the SLNs was found to be 320-498 nm, and the EE was between 32.89 and 56.56 %. The influence of the lipid, surfactant and cosurfactant on the particle size and EE was studied. A histological study revealed no adverse response of SLNs on sheep nasal mucosa. Transmission electron microscopic analysis showed spherical shape particles. Differential scanning calorimetry and X-ray diffraction studies indicated that the drug was completely encapsulated in a lipid matrix. In vitro drug release studies carried out in phosphate buffer (pH 6.6) indicated that the drug transport was of Fickian type. Gamma scintigraphic imaging in rabbits after i.n. administration showed rapid localization of the drug in the brain. Hence, OND SLNs is a promising nasal delivery system for rapid and direct nose-to-brain delivery.

Development and evaluation of olanzapine-loaded PLGA nanoparticles for nose-to-brain delivery: in vitro and in vivo studies

Olanzapine (OZ) is a second-generation or atypical antipsychotic which selectively binds to central dopamine D₂ and serotonin (5-HT(2c)) receptors. It has poor bioavailability due to hepatic first-pass metabolism and low permeability into the brain due to efflux by P-glycoproteins. The present investigation aimed to prepare a nanoparticulate drug delivery system of OZ using poly(lactic-co-glycolic acid) (PLGA) for direct nose-to-brain delivery to provide brain targeting and sustained release. PLGA nanoparticles (NP) were prepared by the nanoprecipitation technique and characterized by entrapment efficiency, particle size, zeta potential, modulated temperature differential scanning calorimetry (MTDSC) and X-ray diffraction (XRD) studies. The NP were evaluated for in vitro release, ex vivo diffusion, toxicity and pharmacokinetic studies. The NP were 91.2±5.2 nm in diameter and had entrapment efficiency 68.91±2.31%. MTDSC studies indicated broadening of the drug peak and a shift in the polymer peak, possibly due to physical interaction or H-bonding between the carbonyl groups of PLGA and the NH groups of OZ, and also due to the plasticization effect of OZ on PLGA. XRD studies indicated a decrease in the crystallinity of OZ or amorphization. In vitro drug release showed a biphasic pattern with initial burst release and, later, sustained release (43.26±0.156% after 120 h), following the Fickian diffusion-based release mechanism. Ex vivo diffusion through sheep nasal mucosa showed 13.21±1.59% of drug diffusion in 210 min from NP. Histopathological study of sheep nasal mucosa showed no significant adverse effect of OZ-loaded NP. In vivo pharmacokinetic studies showed 6.35 and 10.86 times higher uptake of intranasally delivered NP than OZ solution delivered through intravenous (IV) and intranasal (IN) route, respectively. These results proved that OZ could be transported directly to the brain after IN delivery of PLGA NP, enhanced drug concentration in the brain and would therefore be effective in improving the treatment of central nervous system disorders.

In vivo evaluation of alginate microspheres of carvedilol for nasal delivery

Mucoadhesive alginate microspheres of carvedilol (CRV) for nasal administration intended to avoid first pass metabolism and to improve bioavailability were prepared and evaluated. The microspheres were prepared by emulsification cross-linking method. Radiolabeling of CRV and its microspheres was performed by direct labeling with reduced technetium-99m ((99m) Tc). In vivo studies were performed on New Zealand white rabbits by administering the microspheres intranasally using monodose nasal insufflator. The radioactivity was measured in a well-type gamma scintillation counter. The noncompartmental pharmacokinetic analysis was performed. The pattern of deposition and clearance of the microspheres were evaluated using a radioactive tracer and the noninvasive technique of gamma scintigraphy. The clearance of alginate microsphere was compared with that of control lactose. The microspheres were nonaggregated, free flowing powders with spherical shape, and smooth surface. Pharmacokinetics study displayed an increase in area under the curve and hence in relative bioavailability when compared with intravenous administration of drug. The nasal bioavailability was 67.87% which indicates that nasal administration results in improved absorption of CRV. The results of gamma scintigraphy showed that the alginate microspheres had significantly reduced rates of clearance from the rabbit nasal cavity when compared with the control lactose.

Mucoadhesive chitosan microspheres of carvedilol for nasal administration

The aim of the present study was to develop and characterize chitosan mucoadhesive microspheres of carvedilol (CRV) for nasal delivery to improve bioavailability for treatment of hypertension and angina pectoris. The microspheres were prepared by emulsification-cross-linking method and evaluated for size, shape, entrapment efficiency (EE), in vitro mucoadhesion, in vitro drug release, differential scanning calorimetry (DSC) and X-ray diffraction (XRD). The mucoadhesive properties were also evaluated by Freundlich and Langmuir adsorption isotherms. In vivo tests were carried out in rabbits. The microspheres were spherical with size of 20-50 microm, which is favorable for intranasal absorption. The EE was observed from 42% to 68% while percentage mucoadhesion was from 74% to 88%. A strong interaction between mucin and chitosan microspheres was detected explaining adsorption with electrostatic interaction. The microspheres released around 75% of drug in 8 h. DSC and XRD studies revealed that CRV was molecularly dispersed. The absorption rate was rapid and the absolute bioavailability was high, 72.29%. The gamma scintigraphy indicated that the microspheres cleared slowly from the nasal cavity. It was concluded that chitosan microspheres could be used to deliver CRV following nasal administration for improving the bioavailability.

Preparation and evaluation of gelatin/sodium carboxymethyl cellulose polyelectrolyte complex microparticles for controlled delivery of isoniazid

The ratio of gelatin to sodium carboxymethyl cellulose (SCMC) at which maximum yield was obtained was optimized. This optimized ratio of gelatin to SCMC along with other parameters was used to prepare microparticles of different sizes. Vegetable oil was used as emulsion medium. Effect of various factors like amount of surfactant, concentration of polymer on the formation, and size of the microparticles was investigated. These microparticles were used as carrier for isoniazid. Among different cross-linkers, glutaraldehyde was found to be the most effective cross-linker at the temperature and pH at which the reaction was carried out. The loading efficiency and release behavior of loaded microparticles were found to be dependent on the amount of cross-linker used, concentration of drug, and time of immersion. Maximum drug loading efficiency was observed at higher immersion time. The release rate of isoniazid was more at higher pH compared to that of at lower pH. The sizes of the microparticles were investigated by scanning electron microscope. In all the cases, the microparticles formed were found spherical in shape except to those at low stirring speed where they were agglomerated. Fourier transform infrared study indicated the successful incorporation of isoniazid into the microparticles. Differential scanning calorimetry study showed a molecular level dispersion of isoniazid in the microparticles. X-ray diffraction study revealed the development of some crystallinity due to the encapsulation of isoniazid.