Special Issue "Advances in Oral and Buccal Drug Delivery"

A special issue of Pharmaceutics (ISSN 1999-4923). This special issue belongs to the section "Drug Delivery and Controlled Release".

Deadline for manuscript submissions: closed (10 June 2020).

Special Issue Editor

Prof. Dr. Hiraku Onishi
E-Mail Website
Guest Editor
Department of Drug Delivery Research, Hoshi University, 2-4-41 Ebara, Shinagawa-ku, Tokyo 142-8501, Japan
Interests: pharmaceutics; drug delivery systems; nanotechnology

Special Issue Information

Dear Colleagues,

Recently, various types of medicines have been developed and become clinically available. Dosing routes of medicines are chosen based on their physico- and bio-pharmaceutical characteristics. They are often compelled to be used only via parenteral routes because of problems regarding their stabilities and biological membrane obstacles. Parenteral administration is followed by pain and stimulus, and sometimes causes toxic side effects due to inadequate drug concentration.

Oral administrations are the most patient-friendly due to ease-of-use and non-invasive dosing. However, oral administration is inadequate for drugs in which drug absorption is limited due to their physicochemical and/or biological features. In order to solve this problem of absorption efficiency (bioavailability), various physicochemical and biological approaches have been attempted, and the enhancement of the drug solubility and the modification of intestinal membrane permeability have been studied. The improvement of bioavailability or the overcoming of obstacles of intestinal absorption have been challenged a lot as essential subjects. Furthermore, recent advances in oral delivery are introduced in this Special Issue.

In addition, buccal delivery is one of the non-oral mucosal drug applications. Transmucosal delivery enables the rapid absorption and maintenance of systemic levels for a fairly long time. As buccal delivery is simpler compared with nasal, rectal, and pulmonary deliveries, it draws much attention as the second non-invasive administration. For drugs with the first pass effect and strong stimulus in injection, buccal delivery is highly advantageous to ensure such drawbacks can be avoided. Buccal delivery may be available as an alternative to parenteral dosing. Recent developments in buccal delivery are introduced in this content.

Prof. Dr. Hiraku Onishi
Guest Editor

Manuscript Submission Information

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Keywords

  • oral delivery—amorphous and cocrystal
  • oral delivery—transporter and absorption enhancer
  • oral delivery—protein and peptide absorption
  • oral delivery—colonic delivery
  • oral delivery—prodrugs
  • buccal delivery—droplets, emulsions, suspensions, and liposomes
  • buccal delivery—buccal tablets, films, and ointments
  • buccal delivery—absorption enhancers, and mucoadhesive polymers
  • buccal delivery—prodrugs

Published Papers (6 papers)

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Research

Open AccessArticle
Drug-Loaded Lipid-Core Micelles in Mucoadhesive Films as a Novel Dosage Form for Buccal Administration of Poorly Water-Soluble and Biological Drugs
Pharmaceutics 2020, 12(12), 1168; https://doi.org/10.3390/pharmaceutics12121168 - 30 Nov 2020
Cited by 1 | Viewed by 685
Abstract
The aim of the study was to develop a novel buccal dosage form to transport rhodamine 123 and human insulin as models for poorly water-soluble and biological drugs, using lipid-core micelles (LCMs)-loaded mucoadhesive films. LCMs were synthesized by a low-energy hot emulsification process, [...] Read more.
The aim of the study was to develop a novel buccal dosage form to transport rhodamine 123 and human insulin as models for poorly water-soluble and biological drugs, using lipid-core micelles (LCMs)-loaded mucoadhesive films. LCMs were synthesized by a low-energy hot emulsification process, yielding spherically shaped, small-sized, monodispersed and negatively charged carriers with high entrapment efficiency. In vitro release studies demonstrated a higher release of insulin rather than rhodamine from LCMs in simulated physiological conditions, due to an initial burst release effect; however, both release profiles are mainly explained by a diffusion mechanism. Furthermore, LCMs-loaded mucoadhesive films were manufactured and preserved with similar mechanical properties and optimal mucoadhesive behavior compared to nonloaded films. Ex vivo permeation experiments using excised porcine buccal epithelium reveal that both rhodamine and insulin-loaded LCM films elicited a significantly enhanced permeation effect compared to LCMs in suspension and free drugs in solution as controls. Hence, LCMs-loaded mucoadhesive films are suitable as buccal dosage form for the transport and delivery of rhodamine 123 and insulin, as models for poorly water-soluble and biological drugs, respectively. Full article
(This article belongs to the Special Issue Advances in Oral and Buccal Drug Delivery)
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Open AccessArticle
Development and Evaluation of Feline Tailored Amlodipine Besylate Mini-Tablets Using L-lysine as a Candidate Flavouring Agent
Pharmaceutics 2020, 12(10), 917; https://doi.org/10.3390/pharmaceutics12100917 - 24 Sep 2020
Cited by 1 | Viewed by 877
Abstract
Felines may find orally administered medicines unpalatable, thus presenting a problem in the treatment of chronic conditions such as hypertension, a commonly diagnosed condition in felines requiring daily administration of medication. A pertinent example is amlodipine besylate, formulations of which are known to [...] Read more.
Felines may find orally administered medicines unpalatable, thus presenting a problem in the treatment of chronic conditions such as hypertension, a commonly diagnosed condition in felines requiring daily administration of medication. A pertinent example is amlodipine besylate, formulations of which are known to be poorly tolerated by cats. There is therefore a need to develop feline-specific delivery approaches that are both simple to administer and mask the taste of the drug, thereby enhancing the owner’s commitment to treatment and the associated therapeutic outcome for the companion animal. In addition, it is helpful to develop accessible and reproducible means of assessing taste for pre-clinical selection, hence the use of recently developed taste biosensor systems for veterinary applications is an area of interest. This study focuses on developing feline-specific amlodipine besylate formulations by improving the taste using a suitable flavouring agent while reducing dosage form size to a 2 mm diameter mini-tablet. The choice of L-lysine as a flavouring agent was based on the dietary and taste preference of cats. The impact of L-lysine on the taste perception of the formulation was evaluated using a biosensor system (E-tongue) fitted with sensors sensitive to bitter tastes. The results showed L-lysine successfully masked bitterness, while the drug release studies suggest that it has no impact on drug dissolution. In addition, tableting parameters such as tablet mass uniformity, content uniformity, tablet diameter, thickness and hardness were all satisfactory. The present study suggests that amlodipine besylate mini-tablets containing L-lysine could improve the palatability and in turn support product acceptability and ease of administration. These data could have an impact on orally administered medicines for cats and other veterinary species through product differentiation and competitive advantage in the companion animal market sector. The study also outlines the use of the electronic tongue as a tool for formulation selection in the veterinary field. Full article
(This article belongs to the Special Issue Advances in Oral and Buccal Drug Delivery)
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Open AccessArticle
Assessment of CafA Targeted BAR-Encapsulated Nanoparticles against Oral Biofilms
Pharmaceutics 2020, 12(9), 835; https://doi.org/10.3390/pharmaceutics12090835 - 01 Sep 2020
Viewed by 980
Abstract
Porphyromonas gingivalis adherence to Streptococcus gordonii is a crucial initial event that facilitates the colonization of P. gingivalis, a key pathogen in periodontal disease. As such, blocking these early interactions may present a potential avenue to limit P. gingivalis colonization. Nanoparticles encapsulating [...] Read more.
Porphyromonas gingivalis adherence to Streptococcus gordonii is a crucial initial event that facilitates the colonization of P. gingivalis, a key pathogen in periodontal disease. As such, blocking these early interactions may present a potential avenue to limit P. gingivalis colonization. Nanoparticles encapsulating a synthetic peptide BAR (BAR-encapsulated NPs) inhibit P. gingivalis/S. gordonii biofilm formation 1.8-fold more potently relative to free BAR. However, BAR-encapsulated NPs, like many orally delivered formulations, may benefit from a strategy that improves their retention in an open flow environment. Here, we sought to enhance the efficacy of BAR-encapsulated NPs by modifying their surfaces with coaggregation factor A (CafA), a fimbrial protein expressed by the early colonizer, Actinomyces oris. We demonstrate that the targeting moiety, CafA, enhances NP binding and exhibits specificity of adherence to S. gordonii, relative to other oral bacterial species. Furthermore, CafA-modified NPs release inhibitory concentrations of BAR for 12 h, a time frame relevant to oral dosage form delivery. Lastly, CafA-modified NPs potently inhibit P. gingivalis/S. gordonii biofilm formation for up to 12 h and are non-toxic at therapeutically-relevant concentrations. These results suggest that CafA-modified NPs represent a novel and efficacious delivery vehicle for localized, targeted delivery of BAR to P. gingivalis preferred niches. Full article
(This article belongs to the Special Issue Advances in Oral and Buccal Drug Delivery)
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Open AccessArticle
Melt Amorphisation of Orlistat with Mesoporous Silica Using a Supercritical Carbon Dioxide: Effects of Pressure, Temperature, and Drug Loading Ratio and Comparison with Other Conventional Amorphisation Methods
Pharmaceutics 2020, 12(4), 377; https://doi.org/10.3390/pharmaceutics12040377 - 20 Apr 2020
Viewed by 924
Abstract
The aim of this work was to develop an amorphous orlistat-loaded mesoporus silica formulation using the melt-amorphisation by supercritical fluid (MA-SCF) and to investigate the effects of pressure and temperature on the pharmaceutical properties of the developed formulation. In addition, the effect of [...] Read more.
The aim of this work was to develop an amorphous orlistat-loaded mesoporus silica formulation using the melt-amorphisation by supercritical fluid (MA-SCF) and to investigate the effects of pressure and temperature on the pharmaceutical properties of the developed formulation. In addition, the effect of orlistat mass ratio to the mesoporus silica was also evaluated. The carbon dioxide was used as a supercritical fluid, and Neusilin®UFL2 was selected as the mesoporous silica. For comparison with conventional amorphisation methods, orlistat formulations were also prepared by solvent evaporation and hot melt methods. Various pharmaceutical evaluations including differential scanning calorimetry, powder X-ray diffraction, scanning electron microscopy, specific surface area, total pore volume, and content uniformity were performed to characterise the prepared orlistat formulation. The melting point depression and the solubility of orlistat in supercritical carbon dioxide (SC-CO2) were selected for the interpretation of evaluated results in relation to temperature and pressure. The total pore volume of the prepared orlistat-loaded mesoporus silica decreased with an increasing density of SC-CO2 to about 500 g/L at a constant temperature or pressure. From these results, it was suggested that increasing the density of SC-CO2 to about 500 g/L could result in the easier penetration of CO2 into molten orlistat and lower viscosity, hence facilitating the introduction and loading of orlistat into the pores of Neusilin®UFL2. However, when the density of SC-CO2 increased to more than 500 g/L, the total pore volume increased, and this may be due to the release out of orlistat from the pores of Neusilin®UFL2 by the increased orlistat solubility in SC-CO2. Interestingly, as the total pore volume decreased by the filling of the drug, the drug crystallinity decreased; hence, the dissolution rate increased. Furthermore, it was shown that the most desirable mass ratio of Neusilin®UFL2:orlistat for the amorphisation was 1:0.8 at an optimised supercritical condition of 318 K and 10 MPa. Compared with other amorphisation methods, only the sample prepared by the MA-SCF method was in pure amorphous state with the fastest dissolution rate. Therefore, it was concluded that the amorphous orlistat-loaded mesoporus silica prepared using MA-SCF under optimised conditions was more advantageous for enhancing the dissolution rate of orlistat than other conventional amorphisation methods. Full article
(This article belongs to the Special Issue Advances in Oral and Buccal Drug Delivery)
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Open AccessArticle
Design and Evaluation of pH-Dependent Nanosystems Based on Cellulose Acetate Phthalate, Nanoparticles Loaded with Chlorhexidine for Periodontal Treatment
Pharmaceutics 2019, 11(11), 604; https://doi.org/10.3390/pharmaceutics11110604 - 13 Nov 2019
Cited by 6 | Viewed by 1046
Abstract
This work aimed to develop and evaluate pH-dependent systems based on nanospheres (NSphs) and nanocapsules (NCs) loaded with chlorhexidine (CHX) base as a novel formulation for the treatment of periodontal disease. Cellulose acetate phthalate (CAP) was employed as a pH-dependent polymeric material. The [...] Read more.
This work aimed to develop and evaluate pH-dependent systems based on nanospheres (NSphs) and nanocapsules (NCs) loaded with chlorhexidine (CHX) base as a novel formulation for the treatment of periodontal disease. Cellulose acetate phthalate (CAP) was employed as a pH-dependent polymeric material. The NSphs and NCs were prepared using the emulsion-diffusion technique and then characterized according to encapsulation efficiency (EE), size, zeta-potential, morphology, thermal properties, release profiles and a preliminary clinical panel test. The formulations showed 77% and 61% EE and 57% and 84% process efficiency (PE), respectively. Both systems were spherical with an average size of 250–300 nm. Differential scanning calorimetry (DSC) studies showed that the drug has the potential to be dispersed molecularly in the NSph matrix or dissolved in the oily center of the NCs. The CHX release test revealed that the release of NSphs-CHX follows Fickian diffusion involving diffusion-erosion processes. The NCs showed a slower release than the NSphs, following non-Fickian diffusion, which is indicative of anomalous transport. These nanosystems may, therefore, be employed as novel formulations for treating periodontal disease, due to (1) their coverage of a large surface area, (2) the controlled release of active substances at different pH, and (3) potential gingival tissue infiltration. Full article
(This article belongs to the Special Issue Advances in Oral and Buccal Drug Delivery)
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Open AccessArticle
Effects of Hydrophilic Carriers on Structural Transitions and In Vitro Properties of Solid Self-Microemulsifying Drug Delivery Systems
Pharmaceutics 2019, 11(6), 267; https://doi.org/10.3390/pharmaceutics11060267 - 08 Jun 2019
Cited by 5 | Viewed by 1233
Abstract
Self-microemulsifying drug delivery systems (SMEDDS) offer potential for improving the oral bioavailability of poorly water-soluble drugs. However, their susceptibilities during long term storage and in vivo precipitation issues limit their successful commercial application. To overcome these limitations, SMEDDS can be solidified with solid [...] Read more.
Self-microemulsifying drug delivery systems (SMEDDS) offer potential for improving the oral bioavailability of poorly water-soluble drugs. However, their susceptibilities during long term storage and in vivo precipitation issues limit their successful commercial application. To overcome these limitations, SMEDDS can be solidified with solid carriers, thus producing solid self-microemulsifying drug delivery systems (S-SMEDDS). In this study, effects of various hydrophilic carriers on structural transitions and in vitro properties of S-SMEDDS were investigated in order to set up in vitro methods for screening out appropriate carriers for S-SMEDDS. Liquid SMEDDS was prepared and characterized using nimodipine as a model drug. The effects of various hydrophilic carriers on internal microstructure and solubilization of SMEDDS were investigated by conductivity measurement and in vitro dispersion test. The results showed that hydrophilic carriers including dextran 40, maltodextrin and PVP K30 seemed to delay the percolation transition of SMEDDS, allowing it to maintain a microstructure that was more conducive to drug dissolution, thus significantly increasing the solubilization of nimodipine in the self-microemulsifying system and decreasing drug precipitation when dispersed in simulated gastric fluid. S-SMEDDS of nimodipine were prepared by using spray drying with hydrophilic carriers. The effects of various hydrophilic carriers on in vitro properties of S-SMEDDS were investigated by using SEM, DSC, PXRD and in vitro dissolution. The results showed that properties of hydrophilic carriers, especially relative molecular mass of carriers, had obvious influences on surface morphologies of S-SMEDDS, reconstitution of microemulsion and physical state of nimodipine in S-SMEDDS. Considering that in vitro properties of S-SMEDDS are closely related to their pharmacokinetic properties in vivo, the simple and economical in vitro evaluation methods established in this paper can be used to screen solid carriers of S-SMEDDS well. Full article
(This article belongs to the Special Issue Advances in Oral and Buccal Drug Delivery)
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