Buccal Drug Delivery of Pravastatin Sodium

The purpose of this study was to develop and optimize formulations of mucoadhesive bilayered buccal tablets of pravastatin sodium using carrageenan gum as the base matrix. The tablets were prepared by direct compression method. Polyvinyl pyrrolidone (PVP) K 30, Pluronic® F 127, and magnesium oxide were used to improve tablet properties. Magnesium stearate, talc, and lactose were used to aid the compression of tablets. The tablets were found to have good appearance, uniform thickness, diameter, weight, pH, and drug content. A 2³ full factorial design was employed to study the effect of independent variables viz. levels of carrageenan gum, Pluronic F 127 and PVP K30, which significantly influenced characteristics like in vitro mucoadhesive strength, in vitro drug release, swelling index, and in vitro residence time. The tablet was coated with an impermeable backing layer of ethyl cellulose to ensure unidirectional drug release. Different penetration enhancers were tried to improve the permeation of pravastatin sodium through buccal mucosa. Formulation containing 1% sodium lauryl sulfate showed good permeation of pravastatin sodium through mucosa. Histopathological studies revealed no buccal mucosal damage. It can be concluded that buccal route can be one of the alternatives available for the administration of pravastatin sodium.     

Formulation and Evaluation of Buccal Patches for Delivery of Atenolol

Buccal patches for the delivery of atenolol using sodium alginate with various hydrophilic polymers like carbopol 934 P, sodium carboxymethyl cellulose, and hydroxypropyl methylcellulose in various proportions and combinations were fabricated by solvent casting technique. Various physicomechanical parameters like weight variation, thickness, folding endurance, drug content, moisture content, moisture absorption, and various ex vivo mucoadhesion parameters like mucoadhesive strength, force of adhesion, and bond strength were evaluated. An in vitro drug release study was designed, and it was carried out using commercial semipermeable membrane. All these fabricated patches were sustained for 24 h and obeyed first-order release kinetics. Ex vivo drug permeation study was also performed using porcine buccal mucosa, and various drug permeation parameters like flux and lag time were determined.     

Formulation and Evaluation of Bioadhesive Buccal Drug Delivery of Tizanidine Hydrochloride Tablets

The study aim was concerned with formulation and evaluation of bioadhesive buccal drug delivery of tizanidine hydrochloride tablets, which is extensively metabolized by liver. The tablets were prepared by direct compression using bioadhesive polymers such as hydroxylpropyl methylcellulose K4M, sodium carboxymethyl cellulose alone, and a combination of these two polymers. In order to improve the permeation of drug, different permeation enhancers like beta-cyclodextrin (β-CD), hydroxylpropyl beta-cyclodextrin (HP-β-CD), and sodium deoxycholate (SDC) were added to the formulations. The β-CD and HP-β-CD were taken in 1:1 molar ratio to drug in formulations. Bioadhesion strength, ex vivo residence time, swelling, and in vitro dissolution studies and ex vivo permeation studies were performed. In vitro release of optimized bioadhesive buccal tablet was found to be non-Fickian. SDC was taken in 1%, 2%, and 3% w/w of the total tablet weight. Stability studies in natural saliva indicated that optimized formulation has good stability in human saliva. In vivo mucoadhesive behavior of optimized formulation was performed in five healthy male human volunteers and subjective parameters were evaluated.     

Effect of hydrophilic polymers on buccoadhesive eudragit patches of propranolol hydrochloride using factorial design

The purpose of this study was to develop formulations and systematically evaluate in vitro performances of buccoadhesive patches of propranolol hydrochloride using the hydrophobic polymer Eudragit L-100 as the base matrix. The hydrophilic polymers Carbopol 934 and polyvinyl pyrrolidone (PVP) K30 were incorporated into the Eudragit patches, to provide the patches with bioadhesive properties and to modify the rate of drug release. The patches, which were prepared by the solvent casting method, were smooth and elegant in appearance; were uniform in thickness, weight, and drug content; showed no visible cracks; and showed good folding endurance. A 3² full factorial design was employed to study the effect of independent variables like hydrophilic polymers Carbopol 934 and PVP K30, which significantly influenced characteristics like swelling index, ex vivo mucoadhesive strength, in vitro drug release, and ex vivo residence time. A stability study of optimized Eudragit patches was done in natural human saliva; it was found that both drug and buccal patches were stable in human saliva. It can be concluded that the present buccal formulation can be an ideal system to improve the bioavailability of the drug by avoiding hepatic first-pass metabolism. Published: June 22, 2007     

Lyophilized Sustained Release Mucoadhesive Chitosan Sponges for Buccal Buspirone Hydrochloride Delivery: Formulation and In Vitro Evaluation

This work aims to prepare sustained release buccal mucoadhesive lyophilized chitosan sponges of buspirone hydrochloride (BH) to improve its systemic bioavailability. Chitosan sponges were prepared using simple casting/freeze-drying technique according to 3² factorial design where chitosan grade was set at three levels (low, medium, and high molecular weight), and concentration of chitosan solution at three levels (0.5, 1, and 2%). Mucoadhesion force, ex vivo mucoadhesion time, percent BH released after 8 h (Q8h), and time for release of 50% BH (T_50%) were chosen as dependent variables. Additional BH cup and core buccal chitosan sponge were prepared to achieve uni-directional BH release toward the buccal mucosa. Sponges were evaluated in terms of drug content, surface pH, scanning electron microscopy, swelling index, mucoadhesion strength, ex vivo mucoadhesion time, and in vitro drug release. Cup and core sponge (HCH 0.5E) were able to adhere to the buccal mucosa for 8 h. It showed Q8h of 68.89% and exhibited a uni-directional drug release profile following Higuchi diffusion model.KEY WORDS: buspirone HCL, casting/freeze-drying technique, chitosan, cup and core sponge, mucoadhesive buccal sponges     

Transbuccal Delivery of 5-Fluorouracil: Permeation Enhancement and Pharmacokinetic Study

The purpose of this study was to determine the effect of permeation enhancers on the transbuccal delivery of 5-fluorouracil (FU). The effect of permeation enhancers on in vitro buccal permeability was assessed using sodium deoxycholate (SDC), sodium dodecyl sulphate (SDS), sodium tauroglycocholate (STGC), and oleic acid and their concentrations for absorption enhancement were optimized. STGC appeared to be most effective for enhancing the buccal permeation of FU than the other enhancers. These enhancements by STGC were statistically significant (p < 0.05) compared to control. The order of permeation enhancement was STGC > SDS > SDC > oleic acid. Histological investigations were performed on buccal mucosa and indicated no major morphological changes. The enhancing effect of STGC on the buccal absorption of FU was evaluated from the mucoadhesive gels in rabbits. The absolute bioavailability of FU from mucoadhesive gels containing STGC increased 1.6-fold as compared to the gels containing no permeation enhancer. The mean residence time and mean absorption time considerably increased following administration of gel containing penetration enhancer compared with the gel without penetration enhancer.     

Development and Characterization of Mucoadhesive <Emphasis Type="Italic">In Situ</Emphasis> Nasal Gel of Midazolam Prepared with <Emphasis Type="Italic">Ficus carica</Emphasis> Mucilage

The objective of the present study was to prepare mucoadhesive in situ nasal gels with mucilage isolated from fig fruits (Ficus carica, family: Moraceae) containing midazolam hydrochloride. Nasal gels of midazolam were prepared using three different concentrations (0.5%, 1.0% and 1.5% w/v) of F. carica mucilage (FCM) and synthetic polymers (hydroxypropylmethyl cellulose and Carbopol 934). Evaluation of FCM showed that it was as safe as the synthetic polymers for nasal administration. In situ gels were prepared with mixture Pluronic F127 and mucoadhesive agents. Evaluation of the prepared gels was carried out, including determination of viscosity, texture profile analysis and mucoadhesive strength. In vitro drug permeation study was conducted with the gels prepared with and without permeation enhancer (0.5% w/v sodium taurocholate) using excised goat nasal mucosa. In vitro permeation profiles were evaluated, and histological study of nasal mucosae before and after permeation study was also conducted to determine histological change, if any. In vivo experiments conducted in rabbits further confirmed that in situ nasal gels provided better bioavailability of midazolam than the gels prepared from synthetic mucoadhesive polymers. It was observed that the nasal gel containing 0.5% FCM and 0.5% sodium taurocholate exhibited appropriate rheological, mechanical and mucoadhesive properties and showed better drug release profiles. Moreover, this formulation produced no damage to the nasal mucosa that was used for the permeation study, and absolute bioavailability was also higher compared to gels prepared from synthetic polymers.     

A comprehensive development strategy in buccal drug delivery

This work combines several methods in an integrated strategy to develop a matrix for buccal administration. For this purpose, tablets containing selected mucoadhesive polymers loaded with a model drug (omeprazole), free or in a complexed form with cyclodextrins, and in the absence and presence of alkali agents were subjected to a battery of tests. Mucoadhesion studies, including simple factorial analysis, in vitro release studies with both model-dependent and model-independent analysis, and permeation studies were performed. Mucoadhesive profiles indicated that the presence of the drug decreases the mucoadhesion profile, probably due its hydrophobic character. In tablets loaded with the drug complexed with β-cyclodextrin or methyl-β-cyclodextrin, better results were obtained with the methylated derivative. This effect was attributed to the fact that in the case of β-cyclodextrin, more hydroxyl groups are available to interact with the mucoadhesive polymers, thus decreasing the mucoadhesion performance. The same result was observed in presence of the alkali agent (l-arginine), in this case due to the excessive hydrophilic character of l-arginine. Drug release from tablets was also evaluated, and results suggested that the dissolution profile with best characteristics was observed in the matrix loaded with omeprazole complexed with methyl-β-cyclodextrin in the presence of l-arginine. Several mathematical models were applied to the dissolution curves, indicating that the release of the drug, in free or in complexed state, from the mucoadhesive matrices followed a super case II transport, as established on the basis of the Korsmeyer–Peppas function. The feasibility of drug buccal administration was assessed by permeation experiments on porcine buccal mucosa. The amount of drug permeated from mucoadhesive tablets presented a maximum value for the system containing drug complexed with the methylated cyclodextrin derivative in presence of l-arginine. According to these results, the system containing the selected polymer mixture and the drug complexed with methyl-β-cyclodextrin in presence of l-arginine showed a great potential as a buccal drug delivery formulation, in which a good compromise among mucoadhesion, dissolution, and permeation properties was achieved.     

Design and In Vitro/In Vivo Evaluation of Novel Mucoadhesive Buccal Discs of an Antifungal Drug: Relationship Between Swelling, Erosion, and Drug Release

Two groups of fluconazole mucoadhesive buccal discs were prepared: (a) Fluconazole buccal discs prepared by direct compression containing bioadhesive polymers, namely, Carbopol 974p (Cp), sodium carboxymethyl cellulose (SCMC), or sodium alginate (SALG) in combination with hydroxypropyl methylcellulose (HPMC) or hydroxyethyl cellulose (HEC). (b) Fluconazole buccal discs prepared by freeze drying containing different polymer combinations (SCMC/HPMC, Cp/HPMC, SALG/HPMC, and chitosan/SALG). The prepared discs were evaluated by investigating their release pattern, swelling capacity, mucoadhesion properties, and in vitro adhesion time. In vivo evaluation of the buccal disc and in vivo residence times were also performed. Fluconazole salivary concentration after application of fluconazole buccal systems to four healthy volunteers was determined using microbiological assay and high-performance liquid chromatography. SCMC/HPMC buccal disc prepared by direct compression could be considered comparatively superior mucoadhesive disc regarding its in vitro adhesion time, in vivo residence time, and in vitro/in vivo release rates of the drug. Determination of the amount of drug released in saliva after application of the selected fluconazole disc confirmed the ability of the disc to deliver the drug over a period of approximately 5 h and to reduce side effects and possibility of drug interaction encountered during systemic therapy of fluconazole, which would be beneficial in the case of oral candidiasis.     

Development and Evaluation of Buccal Bioadhesive Tablet of an Anti-emetic Agent Ondansetron

The aim of the present study was to develop and evaluate a buccal adhesive tablet containing ondansetron hydrochloride (OH). Special punches and dies were fabricated and used while preparing buccal adhesive tablets. The tablets were prepared using carbopol (CP 934), sodium alginate, sodium carboxymethylcellulose low viscosity (SCMC LV), and hydroxypropylmethylcellulose (HPMC 15cps) as mucoadhsive polymers to impart mucoadhesion and ethyl cellulose to act as an impermeable backing layer. The formulations were prepared by direct compression and characterized by different parameters such as weight uniformity, content uniformity, thickness, hardness, swelling index, in vitro drug release studies, mucoadhesive strength, and ex vivo permeation study. As compared with the optimized formulation composed of OH—5 mg, CP 934—30 mg, SCMC LV—165 mg, PEG 6000—40 mg, lactose—5 mg, magnesium stearate—1.5 mg, and aspartame—2 mg, which gave the maximum release (88.15%), non-bitter (OH) that form namely ondansetron base and complexed ondansetron was used in order to make the selected formulation acceptable to human. The result of the in vitro release studies and permeation studies through bovine buccal mucosa revealed that complexed ondansetron gave the maximum release and permeation. The stability of drug in the optimized adhesive tablet was tested for 6 h in natural human saliva; both the drug and device were found to be stable in natural human saliva. Thus, buccal adhesive tablet of ondansetron could be an alternative route to bypass the hepatic first-pass metabolism and to improve the bioavailability of (OH).     

Comparative Evaluation of Porous Versus Nonporous Mucoadhesive Films as Buccal Delivery System of Glibenclamide

The present research work focused on the comparative assessment of porous versus nonporous films in order to develop a suitable buccoadhesive device for the delivery of glibenclamide. Both films were prepared by solvent casting technique using the 3² full factorial design, developing nine formulations (F1–F9). The films were evaluated for ex vivo mucoadhesive force, ex vivo mucoadhesion time, in vitro drug release (using a modified flow-through drug release apparatus), and ex vivo drug permeation. The mucoadhesive force, mucoadhesion time, swelling index, and tensile strength were observed to be directly proportional to the content of HPMC K4M. The optimized porous film (F4) showed an in vitro drug release of 84.47 ± 0.98%, ex vivo mucoadhesive force of 0.24 ± 0.04 N, and ex vivo mucoadhesion time of 539.11 ± 3.05 min, while the nonporous film (NF4) with the same polymer composition showed a release of 62.66 ± 0.87%, mucoadhesive force of 0.20 ± 0.05 N, and mucoadhesive time of 510 ± 2.00 min. The porous film showed significant differences for drug release and mucoadhesion time (p < 0.05) versus the nonporous film. The mechanism of drug release was observed to follow non-Fickian diffusion (0.1 < n < 0.5) for both porous and nonporous films. Ex vivo permeation studies through chicken buccal mucosa indicated improved drug permeation in porous films versus nonporous films. The present investigation established porous films to be a cost-effective buccoadhesive delivery system of glibenclamide.KEY WORDS: buccoadhesive drug delivery, glibenclamide, in vitro release and ex vivo permeation, porous film     

Mucoadhesive chitosan/gelatin films for buccal delivery of propranolol hydrochloride

The aim of this work was to develop and characterize chitosan/gelatin films as innovative mucoadhesive system for buccal delivery of propranolol hydrochloride. FT-IR and TGA analysis confirmed the interaction between chitosan and gelatin. The presence of higher chitosan amounts in chitosan/gelatin films allowed the lowest percent water-uptake ability (235.1 ± 5.3%) and the highest in vivo residence time in the buccal cavity (240 ± 13 min). Moreover, the presence of mannitol in the formulation allowed 80% drug permeation through porcine buccal mucosa in 5 h. This behaviour suggests that the application of four and two films containing 5 mg of propranolol hydrochloride could be suitable for achieving the proposed daily dose for hypertension and atrial fibrillation treatment, respectively. Another interesting aspect of chitosan/gelatin films was their compatibility with buccal microflora in the absence of drug and their ability to determine growth inhibition for pathogen bacteria, but not for probiotic species, when loaded with drug.     

The Effect of Inkjet Printing over Polymeric Films as Potential Buccal Biologics Delivery Systems

The buccal mucosa appears as a promissory route for biologic drug administration, and pharmaceutical films are flexible dosage forms that can be used in the buccal mucosa as drug delivery systems for either a local or systemic effect. Recently, thin films have been used as printing substrates to manufacture these dosage forms by inkjet printing. As such, it is necessary to investigate the effects of printing biologics on films as substrates in terms of their physical and mucoadhesive properties. Here, we explored solvent casting as a conventional method with two biocompatible polymers, hydroxypropyl methylcellulose, and chitosan, and we used electrospinning process as an electrospun film fabrication of polycaprolactone fibers due to its potential to elicit mucoadhesion. Lysozyme was used as biologic drug model and was formulated as a solution for printing by thermal inkjet printing. Films were characterized before and after printing by mechanical and mucoadhesive properties, surface, and ultrastructure morphology through scanning electron microscopy and solid state properties by thermal analysis. Although minor differences were detected in micrographs and thermograms in all polymeric films tested, neither mechanical nor mucoadhesive properties were affected by these differences. Thus, biologic drug printing on films was successful without affecting their mechanical or mucoadhesive properties. These results open way to explore biologics loading on buccal films by inkjet printing, and future efforts will include further in vitro and in vivo evaluations.     

Formulation and <Emphasis Type="Italic">In Vitro</Emphasis> Evaluation of Xanthan Gum or Carbopol 934-Based Mucoadhesive Patches,Loaded with Nicotine

Bilayer nicotine mucoadhesive patches were prepared and evaluated to determine the feasibility of the formulation as a nicotine replacement product to aid in smoking cessation. Nicotine patches were prepared using xanthan gum or carbopol 934 as a mucoadhesive polymers and ethyl cellulose as a backing layer. The patches were evaluated for their thickness, weight and content uniformity, swelling behavior, drug–polymers interaction, adhesive properties, and drug release. The physicochemical interactions between nicotine and the polymers were investigated by Fourier transform infrared (FTIR) spectroscopy. Mucoadhesion was assessed using two-arm balance method, and the in vitro release was studied using the Franz cell. FTIR revealed that there was an acid base interaction between nicotine and carbopol as well as nicotine and xanthan. Interestingly, the mucoadhesion and in vitro release studies indicated that this interaction was strong between the drug and carbopol whereas it was weak between the drug and xanthan. Loading nicotine concentration to non-medicated patches showed a significant decrease in the mucoadhesion strength of carbopol patches and no significant effect on the mucoadhesion strength of xanthan patches. In vitro release studies of the xanthan patches showed a reasonable fast initial release profile followed by controlled drug release over a 10-h period.     

Thermoreversible Nasal In situ Gel of Venlafaxine Hydrochloride: Formulation, Characterization, and Pharmacodynamic Evaluation

In order to improve the bioavailability of the antidepressant drug, venlafaxine hydrochloride, in situ mucoadhesive thermoreversible gel, was formulated using Lutrol F127 (18%) as a thermo gelling polymer. Mucoadhesion was modulated by trying carbopol 934, PVP K30, HPMC K4M, sodium alginate, tamarind seed gum, and carrageenan as mucoadhesive polymers. Results revealed that as the concentration of mucoadhesive polymer increased the mucoadhesive strength increased but gelation temperature decreased. Formulation was optimized on the basis of clarity, pH, gelation temperature, mucoadhesive strength, gel strength, viscosity, drug content, diffusion through sheep nasal mucosa, histopathological evaluation of mucosa, and pharmacodynamic study in rats. Final formulation T5 containing 18% Lutrol F127 and 0.3% PVP K30 was considered as an optimized formulation. T5 released 97.86 ± 0.073% drug in 150 min with a flux of 0.1545 mg cm⁻² min⁻¹ and gelation temperature 31.17 ± 0.30°C. Histopathological evaluation of nasal mucosa revealed that T5 formulation was safe for nasal administration as it caused no damage to nasal epithelium. From the results of pharmacodynamic study, mainly forced swim test (FST), it was concluded that venlafaxine hydrochloride was more effective as an antidepressant by nasal route as in situ gel nasal drops in comparison to oral administration of equivalent dose.Key words: lutrol F127, mucoadhesive, nasal in situ gel, thermoreversible, venlafaxine HCl     

<Emphasis Type="Italic">In Vitro</Emphasis> Characterization of Chitosan Gels for Buccal Delivery of Celecoxib: Influence of a Penetration Enhancer

Celecoxib (Cx) shows high efficacy in the treatment of osteoarthritis and rheumatoid arthritis as a result of its high specificity for COX-2, without gastrolesivity or interference with platelet function at therapeutic concentrations. Besides of anti-inflammatory effects, Cx also has a potential role for oral cancer chemoprevention. For these conditions, oral administration in long-term treatment is a concern due to its systemic side effects. However, local application at the site of injury (e.g., buccal inflammation conditions or chemoprevention of oral cancer) is a promising way to reduce its toxicity. In this study, the in vitro characterization of mucoadhesive chitosan (CHT) gels associated to Azone® was assessed to explore the potential buccal mucosal administration of Cx in this tissue. Rheological properties of gels were analyzed by a rheometer with cone-plate geometry. In vitro Cx release and permeability studies used artificial membranes and pig cheek mucosa, respectively. Mucoadhesion were measured with a universal test machine. CHT gels (3.0%) containing 2.0% or 3.0% Az showed more appropriate characteristics compared to the others: pH values, rheology, higher amount of Cx retained in the mucosa, and minimal permeation through mucosa, besides the highest mucoadhesion values, ideal for buccal application. Moreover, the flux (J) and amounts of drug released decreased with increased CHT and Az concentrations. CHT gels (3.0%) associated with 2.0% or 3.0% Az may be considered potential delivery systems for buccal administration of Cx.     

Poloxamer 407-based intranasal thermoreversible gel of zolmitriptan-loaded nanoethosomes: formulation,optimization, evaluation and permeation studies

Zolmitriptan is the drug of choice for migraine, but low oral bioavailability (<50%) and recurrence of migraine lead to frequent dosing and increase in associated side effects. Increase in the residence time of drug at the site of drug absorption along with direct nose to brain targeting of zolmitriptan can be a solution to the existing problems. Hence, in the present investigation, thermoreversible intranasal gel of zolmitriptan-loaded nanoethosomes was formulated by using mucoadhesive polymers to increase the residence of the drug into the nasal cavity. The preparation of ethosomes was optimized by using 3² factorial design for percent drug entrapment efficiency, vesicle size, zeta potential, and polydispersity index. Optimized formulation E6 showed the vesicle size (171.67?nm) and entrapment efficiency (66%) when compared with the other formulations. Thermoreversible gels prepared by using poloxamer 407 showed the phase transition temperature at 32–33?°C which was in line with the nasal physiological temperature. The optimized ethosomes were loaded into the thermoreversible mucoadhesive gel optimized by varying concentrations of poloxamer 407, carbopol 934, HPMC K100, and evaluated for gel strength, gelation temperature, mucoadhesive strength, in vitro drug release, and ex vivo drug permeation, where G3 and G6 were found to be optimized formulations. In vitro drug release was studied by different kinetic models suggested that G3 (n?=?0.582) and G6 (n?=?0.648) showed Korsemeyer–Peppas (K_KP) model indicating non-Fickian release profiles. A permeation coefficient of 5.92 and 5.9?µg/cm² for G3 and G6, respectively, revealed very little difference in release rate after 24?h between both the formulations. Non-toxic nature of the gels on columnar epithelial cells was confirmed by histopathological evaluation.     

Mucoadhesive bilayer tablets of propranolol hydrochloride

The purpose of this research was to study mucoadhesive bilayer buccal tablets of propranolol hydrochloride using the bioadhesive polymers sodium alginate (Na-alginate) and Carbopol 934P (CP) along with ethyl cellulose as an impermeable backing layer. The tablets were evaluated for weight variation, thickness, hardness, friability, surface pH, mucoadhesive strength, swelling index, in vitro drug release, ex vivo drug permeation, ex vivo mucoadhesion, and in vivo pharmacodynamics in rabbits. Tablets containing Na-alginate and CP in the ratio of 5∶1 (F2) had the maximum percentage of in vitro drug release without disinte-gration in 12 hours. The swelling index was proportional to Na-alginate content and inversely proportional to CP content. The surface pH of all tablets was found to be satis-factory (7.0±1.5), close to neutral pH; hence, buccal cavity irritation should not occur with these tablets. The mechanism of drug release was found to be non-Fickian diffusion and followed zero-order kinetics. The formulation F4 was optimized based on good biodhesive strength (28.9±0.99 g) and sustained in vitro drug permeation (68.65%±3.69% for 12 hours). The behavior of formulation F4 was examined in human saliva, and both the drug and the buccal tablet were found to be stable. The formulation F4 was applied to rabbit oral mucosa for in vivo studies. The formulation inhibited isoprenaline-induced tachycardia. The studies conducted in rabbits confirmed the sustained release as compared with intravenous administration. Published: September 21, 2007     

Preparation and Characterization of Nicotine–Magnesium Aluminum Silicate Complex-Loaded Sodium Alginate Matrix Tablets for Buccal Delivery

Nicotine (NCT) buccal tablets consisting of sodium alginate (SA) and nicotine–magnesium aluminum silicate (NCT–MAS) complexes acting as drug carriers were prepared using the direct compression method. The effects of the preparation pH levels of the NCT–MAS complexes and the complex/SA ratios on NCT release, permeation across mucosa, and mucoadhesive properties of the tablets were investigated. The NCT–MAS complex-loaded SA tablets had good physical properties and zero-order release kinetics of NCT, which indicate a swelling/erosion-controlled release mechanism. Measurement of unidirectional NCT release and permeation across porcine esophageal mucosa using a modified USP dissolution apparatus 2 showed that NCT delivery was controlled by the swollen gel matrix of the tablets. This matrix, which controlled drug diffusion, resulted from the molecular interactions of SA and MAS. Tablets containing the NCT–MAS complexes prepared at pH 9 showed remarkably higher NCT permeation rates than those containing the complexes prepared at acidic and neutral pH levels. Larger amounts of SA in the tablets decreased NCT release and permeation rates. Additionally, the presence of SA could enhance the mucoadhesive properties of the tablets. These findings suggest that SA plays the important role not only in controlling release and permeation of NCT but also for enhancing the mucoadhesive properties of the NCT–MAS complex-loaded SA tablets, and these tablets demonstrate a promising buccal delivery system for NCT.     

Thermally Triggered Mucoadhesive In Situ Gel of Loratadine: β-Cyclodextrin Complex for Nasal Delivery

The aim of the present study was to increase the solubility of an anti-allergic drug loratadine by making its inclusion complex with β-cyclodextrin and to develop it’s thermally triggered mucoadhesive in situ nasal gel so as to overcome first-pass effect and consequently enhance its bioavailability. A total of eight formulations were prepared by cold method and optimized by 2³ full factorial design. Independent variables (concentration of poloxamer 407, concentration of carbopol 934 P, and pure drug or its inclusion complex) were optimized in order to achieve desired gelling temperature with sufficient mucoadhesive strength and maximum permeation across experimental nasal membrane. The design was validated by extra design checkpoint formulation (F9) and Pareto charts were used to help eliminate terms that did not have a statistically significant effect. The response surface plots and possible interactions between independent variables were analyzed using Design Expert Software 8.0.2 (Stat Ease, Inc., USA). Faster drug permeation with zero-order kinetics and target flux was achieved with formulation containing drug: β-cyclodextrin complex rather than those made with free drug. The optimized formulation (F8) with a gelling temperature of 28.6 ± 0.47°C and highest mucoadhesive strength of 7,676.0 ± 0.97 dyn/cm² displayed 97.74 ± 0.87% cumulative drug permeation at 6 h. It was stable for over 3 months and histological examination revealed no remarkable damage to the nasal tissue.