Mucoadhesive chitosan microspheres of carvedilol for nasal administration

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.

Nose-to-Heart Approach: Unveiling an Alternative Route of Acute Treatment

Intranasal (IN) administration has emerged as a novel approach for rapid systemic absorption, with potential applicability in the management of acute cardiovascular events. This review explores the evolution of IN cardiovascular pharmacotherapy, emphasizing its potential in achieving systemic effects and bypassing the first-pass metabolism associated with oral administration. The extensive vascularization of nasal mucosa and a porous endothelial basement membrane facilitate efficient drug absorption into the bloodstream. The IN route ensures a critical swift onset of action, which allows self-administration in at-home settings. For instance, etripamil nasal spray, a first-in-class formulation, exemplifies the therapeutic potential of this approach in the treatment of spontaneous supraventricular tachycardia. The review critically assesses studies on IN formulations for angina, acute myocardial infarction, hypertensive episodes, and cardiac arrhythmias. Preclinical evaluations of beta-blockers, calcium-channel blockers, and antianginal drugs demonstrate the feasibility of IN administration for acute cardiovascular events. A small number of clinical trials have revealed promising results, emphasizing the superiority of IN drug delivery over oral administration in terms of bioavailability and onset of action. Unambiguously, the limited clinical trials and patient enrollment pose challenges in generalizing experimental outcomes. However, the nose-to-heart approach has clinical potential.

Nano-Spray-Dried Levocetirizine Dihydrochloride with Mucoadhesive Carriers and Cyclodextrins for Nasal Administration

Antihistamines such as levocetirizine dihydrochloride (LC) are commercially used in oral tablets and oral drops to reduce allergic symptoms. In this study, LC was nano-spray-dried using three mucoadhesive polymers and four cyclodextrin species to form composite powders for nasal administration. The product was composed of hydroxypropyl methylcellulose polymer, including LC as a zwitterion, after neutralization by NaOH, and XRD investigations verified its amorphous state. This and a sulfobutylated-beta-cyclodextrin sodium salt-containing sample showed crystal peaks due to NaCl content as products of the neutralization reaction in the solutions before drying. The average particle size of the spherical microparticles was between 2.42 and 3.44 µm, except for those containing a polyvinyl alcohol excipient, which were characterized by a medium diameter of 29.80 µm. The drug was completely and immediately liberated from all the samples at pH 5.6 and 32 °C; i.e., the carriers did not change the good dissolution behavior of LC. A permeability test was carried out by dipping the synthetic cellulose ester membrane in isopropyl myristate using modified horizontal diffusion cells. The spray-dried powder with β-cyclodextrin showed the highest permeability (188.37 µg/cm²/h), as this additive was the least hydrophilic. Products prepared with other cyclodextrins (randomly methylated-beta-cyclodextrin, sulfobutylated-beta-cyclodextrin sodium salt and (hydroxypropyl)-beta-cyclodextrin) showed similar or slightly higher penetration abilities than LC. Other polymer excipients resulted in lower penetration of the active agent than the pure LC.

Taste Masking of Promethazine Hydrochloride Using l-Arginine Polyamide-Based Nanocapsules

Promethazine hydrochloride (PMZ), a potent H1-histamine blocker widely used to prevent motion sickness, dizziness, nausea, and vomiting, has a bitter taste. In the present study, taste masked PMZ nanocapsules (NCs) were prepared using an interfacial polycondensation technique. A one-step approach was used to expedite the synthesis of NCs made from a biocompatible and biodegradable polyamide based on l-arginine. The produced NCs had an average particle size of 193.63 ± 39.1 nm and a zeta potential of −31.7 ± 1.25 mV, indicating their stability. The NCs were characterized using differential scanning calorimetric analysis and X-ray diffraction, as well as transmission electron microscopy that demonstrated the formation of the NCs and the incorporation of PMZ within the polymer. The in vitro release study of the PMZ-loaded NCs displayed a 0.91 ± 0.02% release of PMZ after 10 min using artificial saliva as the dissolution media, indicating excellent taste masked particles. The in vivo study using mice revealed that the amount of fluid consumed by the PMZ-NCs group was significantly higher than that consumed by the free PMZ group (p < 0.05). This study confirmed that NCs using polyamides based on l-arginine and interfacial polycondensation can serve as a good platform for the effective taste masking of bitter actives.

Crab (Charybdis natator) exoskeleton derived chitosan nanoparticles for the in vivo delivery of poorly water-soluble drug: Ibuprofen

The study aims to extract and purify chitosan (CS) from the exoskeleton of crab (C. natator) and develop ibuprofen (IBU) encapsulated CS nanoparticles (IBU-CSNPs). Analysis of purified CS revealed characteristic functional and crystallinity peaks. Moreover, morphological analysis of prepared IBU-CSNPs showed uniform spherical shape with a size range of 40-100 nm whereas encapsulation efficiency (EE%) and loading capacity (LC%) were estimated to be 68.94 ± 1.61% and 28 ± 1.18% respectively. Further, in vitro release profile of IBU from IBU-CSNPs was observed to be in biphasic form with initial release up to 15 h followed by the sustained release in different test conditions. Further, the effects of purified CS on the viability of RAW264.7 cells exhibited no toxic effects in higher concentrations. Furthermore, fluorescein isothiocyanate (FITC) conjugated nanoparticles (FITC-IBU-CSNPs) were investigated on in vivo model of adult zebrafish for time-dependent circulation and accumulation of the drug through the nano-carrier system. It was observed that the drug diffusion from the nanoparticles was in a sustained manner throughout the gastrointestinal region which resulted in suppression of inflammation. Overall, this study provides an effective and facile process for preparing a crab CS-based nano-carrier system used for the delivery of IBU in vivo which may help in the curing of prolonged chronic inflammatory diseases. Moreover, it may also help to reduce adverse effects of these drugs in the gastrointestinal tract such as ulcers and bleeding.

Multiple Roles of Chitosan in Mucosal Drug Delivery: An Updated Review

Chitosan (CS) is a linear polysaccharide obtained by the deacetylation of chitin, which, after cellulose, is the second biopolymer most abundant in nature, being the primary component of the exoskeleton of crustaceans and insects. Since joining the pharmaceutical field, in the early 1990s, CS attracted great interest, which has constantly increased over the years, due to its several beneficial and favorable features, including large availability, biocompatibility, biodegradability, non-toxicity, simplicity of chemical modifications, mucoadhesion and permeation enhancer power, joined to its capability of forming films, hydrogels and micro- and nanoparticles. Moreover, its cationic character, which renders it unique among biodegradable polymers, is responsible for the ability of CS to strongly interact with different types of molecules and for its intrinsic antimicrobial, anti-inflammatory and hemostatic activities. However, its pH-dependent solubility and susceptibility to ions presence may represent serious drawbacks and require suitable strategies to be overcome. Presently, CS and its derivatives are widely investigated for a great variety of pharmaceutical applications, particularly in drug delivery. Among the alternative routes to overcome the problems related to the classic oral drug administration, the mucosal route is becoming the favorite non-invasive delivery pathway. This review aims to provide an updated overview of the applications of CS and its derivatives in novel formulations intended for different methods of mucosal drug delivery.

Chitosan as Valuable Excipient for Oral and Topical Carvedilol Delivery Systems

Chitosan is a valued excipient due to its biocompatibility properties and increasing solubility of poorly water-soluble drugs. The research presented in this paper concerns the preparation of binary combinations of chitosan (deacetylated chitin) with carvedilol (beta-blocker) to develop a formulation with a modified carvedilol release profile. As part of the research, six physical mixtures of chitosan with carvedilol were obtained and identified by spectral (PXRD, FT-IR, and Raman), thermal (DSC), and microscopic (SEM) methods. The next stage of the research estimated the profile changes and the dissolution rate for carvedilol in the obtained drug delivery systems; the reference sample was pure carvedilol. The studies were conducted at pH = 1.2 and 6.8, simulating the gastrointestinal tract conditions. Quantitative changes of carvedilol were determined using the developed isocratic UHPLC-DAD method. Established apparent permeability coefficients proved the changes in carvedilol's permeability after introducing a drug delivery system through membranes simulating the gastrointestinal tract and skin walls. A bioadhesive potential of carvedilol-chitosan systems was confirmed using the in vitro model. The conducted research and the obtained results indicate a significant potential of using chitosan as an excipient in modern oral or epidermal drug delivery systems of carvedilol.

Use of combined nanocarrier system based on chitosan nanoparticles and phospholipids complex for improved delivery of ferulic acid

A novel nanocarrier system of phospholipids complex loaded chitosan nanoparticles (FAPLC CNPs) was developed to improve the oral bioavailability and antioxidant potential of FA. FAPLC CNPs were optimized using a Box-Behnken Design (BBD). FAPLC CNPs were characterized using differential scanning calorimetry, Fourier transforms infrared spectroscopy, powder x-ray diffractometry, proton nuclear magnetic resonance, solubility, in vitro dissolution, ex vivo permeation, and in vivo antioxidant activity in carbon tetrachloride (CCl₄)-induced albino rat model. The characterization studies indicated a formation of the complex as well as FAPLC CNPs. The FAPLC CNPs exhibited a lower particle size ~123.27 nm, PDI value ~0.31, and positive zeta potential ~32 mV respectively. Functional characterization studies revealed a significant improvement in the aqueous solubility, dissolution, and permeation rate of FAPLC and FAPLC CNPs compared to FA and FA CNPs. The FAPLC CNPs showed significant enhancement of in vivo antioxidant activity of FA by restoring the elevated marker enzymes in the CCl₄-intoxicated rat model compared to FA CNPs. Moreover, the pharmacokinetic analysis demonstrated a significant enhancement of oral bioavailability of FA from FAPLC CNPs compared to FA CNPs. These findings show that FAPLC CNPs could be used as an effective nanocarrier for improving the oral delivery of FA.

Physicochemical and pharmacological evaluation of carvedilol-eudragit® RS100 electrosprayed nanostructures

OBJECTIVES

This study was carried out to boost the pharmacologic influence of carvedilol (CAR) (as a poorly water-soluble drug) by developing CAR-eudragit® RS100 (Eud) nanofibers and nanobeads benefiting an electrospraying approach.

MATERIALS AND METHODS

CAR-Eud nanoformulations with varying ratios (1:5 and 1:10) at total solution concentrations of 10 %, 15 % and 20 % w/v were formulated.

RESULTS

The solution concentration remarkably impressed the size and morphology of the samples; in which, the nanobeads (mean diameter of 135.83 nm) were formed at low solution concentrations and high concentrations led to nanofibers (mean diameter of 193.45 nm) formation. DSC thermographs and PXRD patterns along with FTIR spectrum precisely showed CAR amorphization and no probable chemical interactions between CAR and Eud in the electrosprayed nanosystems. The in vitro release considerations demonstrated that the nanoformulations with the drug: polymer ratios of 1:10 and 1:5 depict rapid dissolution rate compared to the physical mixtures (PMs) and the pure drug. The in vivo studies in Wistar male rats suggested that the electrosprayed nanoformulation (1:10; 20 %) reduced the isoproterenol (ISO) induced elevation of heart rate, necrosis and accumulation of neutrophils in the heart tissue more efficient than the pure drug and PM.

CONCLUSION

Our finding illustrated that the electrospraying as a profitable one-step procedure could be productively benefited to improve the physicochemical features and pharmacologic influences of CAR.

How to characterize a nasal product. The state of the art of in vitro and ex vivo specific methods

Nasal delivery offers many benefits over other conventional routes of delivery (e.g. oral or intravenous administration). Benefits include, among others, a fast onset of action, non-invasiveness and direct access to the central nervous system. The nasal cavity is not only limited to local application (e.g. rhinosinusitis) but can also provide direct access to other sites in the body (e.g. the central nervous system or systemic circulation). However, both the anatomy and the physiology of the nose impose their own limitations, such as a small volume for delivery or rapid mucociliary clearance. To meet nasal-specific criteria, the formulator has to complete a plethora of tests, in vitro and ex vivo, to assess the efficacy and tolerance of a new drug-delivery system. Moreover, depending on the desired therapeutic effect, the delivery of the drug should target a specific pathway that could potentially be achieved through a modified release of this drug. Therefore, this review focuses on specific techniques that should be performed when a nasal formulation is developed. The review covers both the tests recommended by regulatory agencies (e.g. the Food and Drug Administration) and other complementary experiments frequently performed in the field.

In situ thermo-co-electroresponsive mucogel for controlled release of bioactive agent

The purpose of this work was to develop an in situ thermosensitive electro-responsive mucoadhesive gel loaded with bioactive agent (nanocomposite) meant for nose to brain delivery in a controllable manner when electric stimulation is applied. Nanocomposite was developed using a combinatorial blending of chitosan, hydroxypropylmethylcellulose, pluronic F127 and polyaniline which was then loaded with BCNU-Nano-co-Plex (the bioactive agent). The nanocomposite was a liquid at room temperature but formed an in situ mucogel at a temperature of 27.5 ± 0.5 °C. Furthermore, the nanocomposite possessed a redox element which makes it responsive to electrical stimulation (ES). The stimuli responsiveness enabled the formulation to release the bioactive agent when electrical potential was applied and demonstrated a desired 10.28% release of nanoparticles per application cycle. The results further revealed pore formation within the formulation which accommodated the loaded nanoparticles. The release profile also demonstrated a pulsatile release of the bioactive material when subjected to ES. This formulation may therefore be useful as a nose to brain drug delivery system that can be modulated to deliver bioactive agents to the brain via electro-actuation in an "on-off" drug release kinetics by means of an external ES for a controlled nose-to-brain delivery.

Novel in situ gelling vaginal sponges of sildenafil citrate-based cubosomes for uterine targeting

Sildenafil citrate (SIL), a type 5-specific phosphodiesterase inhibitor, demonstrates valuable results in the management of infertility in women; however, the absence of vaginal dosage form in addition to the associated oral adverse effects minimize its clinical performance. The present study is concerned with SIL uterine targeting following intravaginal administration via optimization of cubosomal in situ gelling sponges (CIS). An emulsification method was employed for preparation of cubosomal dispersions incorporating glyceryl monooleate as a lipid phase and poloxamer 407 as a surfactant with or without polyvinyl alcohol as a stabilizer. Cubosomes were estimated regarding entrapment efficiency (EE%), particle size, and in vitro drug release. Chitosan (2% w/w) was incorporated into the optimum formulation and then lyophilized into small sponges. For the CIS, in vivo histopathological and pharmacokinetic studies were conducted on female Wistar rats and compared with intravaginal free SIL sponges (FIS) and oral SIL solution. SIL-loaded cubosomes showed EE% ranging between 32.15 and 72.01%, particle size in the range of 150.81–446.02 nm and sustained drug release over 8 h. Histopathological study revealed a significant enlargement in endometrial thickness with congestion and dilatation of endometrial blood vessels in intravaginal CIS compared to intravaginal FIS and oral-treated groups. The pharmacokinetic study demonstrated higher AUC_0–∞ and C_max with oral administration compared to intravaginal CIS or intravaginal FIS indicating potential involvement of first uterine pass effect after intravaginal administration. Finally, intravaginal CIS could be considered as a promising platform for SIL uterine targeting with minimized systemic exposure and side effects.

Formulation and In-vivo Pharmacokinetic Consideration of Intranasal Microemulsion and Mucoadhesive Microemulsion of Rivastigmine for Brain Targeting

PURPOSE

Presence of tight junctions in blood brain barrier (BBB) pose a major hurdle for delivery of drug and severely affects adequate therapeutic concentration to reach the brain. In present work, we have selected Rivastigmine hydrogen tartrate (RHT), a reversible cholinesterase inhibitor, which exhibits extensive first-pass metabolism, resulting in limited absolute bioavailability (36%). RHT shows extremely low aqueous solubility and poor penetration, resulting in inadequate concentration reaching the brain, thus necessitating frequent oral dosing. To overcome these problems of RHT, microemulsion (ME) and mucoadhesive microemulsion (MME) of RHT were formulated for brain targeting via intranasal delivery route and compared on the basis of in vivo pharmacokinetics.

METHODS

ME and MME formulations containing RHT were developed by water titration method. Characterization of ME and MME was done for various physicochemical parameters, nasal spray pattern, and in vivo pharmacokinetics quantitatively and qualitatively (gamma scintigraphy studies).

RESULTS

The developed ME and MME were transparent having globule size approximately in the range of 53-55 nm. Pharmacokinetic studies showed higher values for C_max and DTP for intranasal RHT: CH-ME over RHT-ME, thus indicating the effect of chitosan in modulating tight junctions, thereby enhanced paracellular transport of RHT.

CONCLUSION

Gamma scintigraphy and in vivo pharmacokinetic study suggested enhanced RHT concentration, upon intranasal administration of RHT:CH-ME, compare with other groups administered formulations intranasally. These findings suggested the potential of non-invasive intranasal route for brain delivery, especially for therapeutics, facing challenges in oral administration.

Opportunity and challenges of nasal powders: Drug formulation and delivery

In the field of nasal drug delivery, among the preparations defined by the European Pharmacopoeia, nasal powders facilitate the formulation of poorly water-soluble active compounds. They often display a simple composition in excipients (if any), allow for the administration of larger drug doses and enhance drug diffusion and absorption across the mucosa, improving bioavailability compared to nasal liquids. Despite the positive features, however, nasal products in this form still struggle to enter the market: the few available on the market are Onzetra Xsail® (sumatriptan) for migraine relief and, for the treatment of rhinitis, Rhinocort® Turbuhaler® (budesonide), Teijin Rhinocort® (beclomethasone dipropionate) and Erizas® (dexamethasone cipecilate). Hence, this review tries to understand why nasal powder formulations are still less common than liquid ones by analyzing whether this depends on the lack of (i) real evidence of superior therapeutic benefit of powders, (ii) therapeutic and/or commercial interest, (iii) efficient manufacturing methods or (iv) availability of suitable and affordable delivery devices. To this purpose, the reader's attention will be guided through nasal powder formulation strategies and manufacturing techniques, eventually giving up-to-date evidences of therapeutic efficacy in vivo. Advancements in the technology of insufflation devices will also be provided as nasal drug products are typical drug-device combinations.

Direct and enhanced delivery of nanoliposomes of anti schizophrenic agent to the brain through nasal route

The problem of inadequate oral bioavailability of Quetiapine Fumarate, a lipophilic drug used for schizophrenia, due to hepatic metabolism and repulsion by brain barrier was attempted in this study. Combination of two approaches, viz. Quetiapine inclusion into the liposomal carrier for better diffusion and administration through nasal route to avoid hepatic metabolism and barrier elimination was applied. Thin film hydration followed by sonication method was employed in liposome preparation and the formulation was optimized using 32 full factorial design. The number of sonication cycles (X1) of 2 min and 80% amplitude and molar ratio of constructional components such as cholesterol to egg phosphatidylcholine (X2) as independent variables and a % of entrapment efficiency (Y1) and cumulative in vitro drug release (Y2) at 6 h as dependent variables was selected. Batch F7 prepared by 2 cycles of sonication and 1:3 M ratio of cholesterol:egg phosphatidylcholine was optimized as a consequence of substantial entrapment efficiency of 75.63 ± 3.77%, and 99.92 ± 1.88% drug release and 32.33 ± 1.53% drug diffusion, which was optimum among all other batches at 6 h. Diffusion study was done for all the batches of liposomal formulation by using sheep nasal mucosa and good amount with better diffusion rate was measured which proved liposomal dispersion a virtuous delivery system for brain drug delivery through nasal route. Results of in vivo, ciliotoxicity and gamma scintigraphy studies on mice supported the above inference.

Tartrate/tripolyphosphate as co-crosslinker for water soluble chitosan used in protein antigens encapsulation

In drug delivery research, several toxic chemical crosslinkers and non-toxic ionic crosslinkers have been exploited for the synthesis of microparticles from acetic acid soluble chitosan. This paper hypothesized the implementation of sodium potassium tartrate (SPT) as an alternative crosslinker for sodium tripolyphosphate (TPP) and SPT/TPP co-crosslinkers for synthesis of the microparticles using water soluble chitosan (WSC) for encapsulation of Bovine serum albumin (BSA) as a model protein, and Tetanus toxoid (TT) as a model vaccine. The crosslinking was confirmed by FT-IR, SEM with EDS. The XRD entailed molecular dispersion of proteins and thermal analysis confirmed the higher stability of STP/TPP co-crosslinked formulations. The resultant microparticles were exhibiting crosslinking degree (52-67%), entrapment efficiency (72-80%), particle size (0.3-1.7μm), zeta potential (+24 to 46mV) and mucoadhesion (41-68%). The superiority of SPT over TPP was confirmed by higher crosslinking degree and entrapment efficiency. However, co-crosslinking were advantageous in higher regression values for Langmuir adsorption isotherm, slower swelling tendency and extended 30days controlled in-vitro release study. TT release obeyed the Quasi-Fickian diffusion mechanism for single and cocrosslinked formulations. Overall, in crosslinking of chitosan as biological macromolecules, STP/TPP may be alternative for single ionic crosslinked formulations for protein antigen delivery.

Immune response elicited by an intranasally delivered HBsAg low-dose adsorbed to poly-ε-caprolactone based nanoparticles

Among new strategies to increase hepatitis B virus (HBV) vaccination, especially in developing countries, the development of self-administered vaccines is considered one of the most valuable. Nasal vaccination using polymeric nanoparticles (NPs) constitutes a valid approach to this issue. In detail, poly-ε-caprolactone (PCL)/chitosan NPs present advantages as a mucosal vaccine delivery system: the high resistance of PCL against degradation in biological fluids and the mucoadhesive and immunostimulatory properties of chitosan. In vitro studies revealed these NPs were retained in a mucus-secreting pulmonary epithelial cell line and were capable of entering into differentiated epithelial cells. The intranasal (IN) administration of 3 different doses of HBsAg (1.5 μg, 5 μg and 10 μg) adsorbed on a fixed amount of PCL/chitosan NPs (1614 μg) generated identical titers of serum anti-HBsAg IgG and anti-HBsAg sIgA in mice nasal secretions. Besides other factors, the NP surface characteristics, particularly, zeta potential differences among the administered formulations are believed to be implicated in the outcome of the immune response generated.

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.

Comparative study between simple and optimized liposomal dispersion of quetiapine fumarate for diffusion through nasal route

CONTEXT

Nasal route of drug administration is preferred more and more for the targeted delivery to the brain in current drug development scenario due to its ease of use, reliability, quick action, and lesser side effects. Those CNS drugs which have limited oral bioavailability due to pharmacokinetic consequences and brain barrier repulsion are getting onto this direction.

OBJECTIVE

Quetiapine fumarate, an analogous to above and an antischizophrenic agent, is tested for its diffusion property with and without lipophilic carrier through sheep nasal membrane. Being a BCS class II' and high permeable candidate, it tends to crossover easily, so made up in a simple dispersion.

MATERIALS AND METHODS

To improve its diffusion rate, it was embedded into liposomal dispersion, which has proven that it has advanced efficiency for diffusion. For this, both the formulations were checked and compared for their diffusion profile, as it is an essential property for bioavailability through nasal route. Comparison was made on the basis of % drug diffusion within 6 h, rate, mechanism, profile, and coefficient.

RESULTS

Liposomal dispersion has been proved superior with greater percentage diffusion of 32.61 ± 1.70 and very high permeability with a coefficient value of 4.1334 ± 0.7321 (× 10 (-) (5 )cm/s). Diffusion profile comparison bearing dissimilarity of 18 and similarity of 74 indicated that the diffusion profiles of liposomal dispersions and simple dispersion were similar but not identical.

CONCLUSION

Liposomal diffusion supremacy was further sustained by in vivo, ciliotoxicity, and gamma scintigraphy studies.

Intranasal drug delivery of olanzapine-loaded chitosan nanoparticles

The aim of this study was to investigate olanzapine (OZ) systemic absolute bioavailability after intranasal (i.n.) administration in vivo to conscious rabbits. Furthermore, the study investigated the potential use of chitosan nanoparticles as a delivery system to enhance the systemic bioavailability of olanzapine following intranasal administration. Olanzapine-loaded chitosan nanoparticles were prepared through ionotropic gelation of chitosan with tripolyphosphate anions and studied in terms of their size, drug loading, and in vitro release. The OZ nanoparticles were administered i.n. to rabbits, and OZ plasma concentration at predetermined time points was compared to i.n. administration of OZ in solution. The concentrations of OZ in plasma were analyzed by ultra performance liquid chromatography mass spectroscopy (UPLC/MS). OZ-loaded chitosan nanoparticles significantly (p < 0.05) enhanced systemic absorption with 51 ± 11.2% absolute bioavailability as compared to 28 ± 6.7% after i.n. administration of OZ solution. The results of the present study suggest that intranasal administration of OZ-loaded chitosan nanoparticles formulation could be an attractive modality for delivery of OZ systemically.

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.

Formulation and in vitro evaluation of salbutamol sulphate in situ gelling nasal inserts

The aim of this study was to formulate salbutamol sulfate (SS), a model drug, as mucoadhesive in situ gelling inserts having a high potential as nasal drug delivery system bypassing the first-pass metabolism. In situ gelling inserts, each containing 1.4% SS and 2% gel-forming polymer, hydroxypropyl methylcellulose (HPMC), carboxymethylcellulose sodium (CMC Na), sodium alginate (AL), and chitosan (CH) were prepared. The inserts were investigated for their different physicochemical properties. The weight of inserts was 16-27 mg, drug content was 3.9-4.2 mg, thickness ranged between 15 and 28 μm and surface pH was 5-7. Cumulative drug released from the inserts exhibited extended release for more than 10 h following the decreasing order: CH>AL>CMC Na>HPMC. The drug release from CMC Na and AL inserts followed zero-order kinetics while HPMC and CH inserts exhibited non-Fickian diffusion mechanism. The inserts exhibited different water uptake (7-23%) with the smallest values for CH. Differential scanning calorimetry study pointed out possible interaction of SS and oppositely charged anionic polymers (CMC Na and AL). The mucoadhesive in situ gelling inserts exhibited satisfactory mucoadhesive and extended drug release characteristics. The inserts could be used for nasal delivery of SS over about 12 h; bypassing the hepatic first-pass metabolism without potential irritation.

Investigation of potential injectable polymeric biomaterials for bone regeneration

This article reviews the potential injectable polymeric biomaterial scaffolds currently being investigated for application in bone tissue regeneration. Two types of injectable biomaterial scaffolds are focused in this review, including injectable microspheres and injectable gels. The injectable microspheres section covers several polymeric materials, including poly(L-lactide-co-glycolide)-PLGA, poly(propylene fumarate), and chitosan. The injectable gel section covers alginate gels, hyaluronan hydrogels, poly(ethylene-glycol)-PEG hydrogels, and PEG-PLGA copolymer hydrogels. This review focuses on the effect of cellular behavior in vitro and in vivo in terms of material properties of polymers, such as biodegradation, biocompatibility, porosity, microsphere size, and cross-linking nature. Injectable polymeric biomaterials offer a major advantage for orthopedic applications by allowing the ability to use noninvasive or minimally invasive treatment methods. Therefore, combining injectable polymeric biomaterial scaffolds with cells have a significant potential to treat orthopedic bone defects, including spine fusion, and craniofacial and periodontal defects.

Design and application of chitosan microspheres as oral and nasal vaccine carriers: an updated review

Chitosan, a natural biodegradable polymer, is of great interest in biomedical research due to its excellent properties including bioavailability, nontoxicity, high charge density, and mucoadhesivity, which creates immense potential for various pharmaceutical applications. It has gelling properties when it interacts with counterions such as sulfates or polyphosphates and when it crosslinks with glutaraldehyde. This characteristic facilitates its usefulness in the coating or entrapment of biochemicals, drugs, antigenic molecules as a vaccine candidate, and microorganisms. Therefore, chitosan together with the advance of nanotechnology can be effectively applied as a carrier system for vaccine delivery. In fact, chitosan microspheres have been studied as a promising carrier system for mucosal vaccination, especially via the oral and nasal route to induce enhanced immune responses. Moreover, the thiolated form of chitosan is of considerable interest due to its improved mucoadhesivity, permeability, stability, and controlled/extended release profile. This review describes the various methods used to design and synthesize chitosan microspheres and recent updates on their potential applications for oral and nasal delivery of vaccines. The potential use of thiolated chitosan microspheres as next-generation mucosal vaccine carriers is also discussed.

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.

Biomedical Applications of Biodegradable Polymers

Utilization of polymers as biomaterials has greatly impacted the advancement of modern medicine. Specifically, polymeric biomaterials that are biodegradable provide the significant advantage of being able to be broken down and removed after they have served their function. Applications are wide ranging with degradable polymers being used clinically as surgical sutures and implants. In order to fit functional demand, materials with desired physical, chemical, biological, biomechanical and degradation properties must be selected. Fortunately, a wide range of natural and synthetic degradable polymers has been investigated for biomedical applications with novel materials constantly being developed to meet new challenges. This review summarizes the most recent advances in the field over the past 4 years, specifically highlighting new and interesting discoveries in tissue engineering and drug delivery applications.

Design and development of nasal mucoadhesive microspheres containing tramadol HCl for CNS targeting

In the present study, tramadol HCl microspheres were designed in order to accomplish rapid delivery of drug to the brain. For this purpose, lower viscosity grade HPMC (E15) was chosen as mucoadhesive polymer and used at different drug/polymer ratios in the microspheres formulations. The spray-dried microspheres were evaluated with respect to the production yield, incorporation efficiency, particle size, mucoadhesive property, in vitro drug release, histopathological study, and radio imaging study in rabbits. DSC and XRD study showed molecular dispersion and conversion of the drug into amorphous form. Size and surface morphology of microspheres was analyzed by SEM and found to be spherical in shape with smooth surface. It was found that the particle size, swelling ability, and incorporation efficiency of microspheres increase with increasing drug-to-polymer ratio. Microspheres show adequate mucoadhesion and do not have any destructive effect on nasal mucosa. In vitro drug release of optimized formulation was found to be 94% after 90 min. The radio imaging study indicated localization of drug in the brain. Hence, tramadol HCl microspheres based on a HPMC E15 may be a promising nasal delivery system for CNS targeting.