A Review on Lipid-Based Nanoformulations for Targeting Brain through Non-invasive Nasal Route

The nasal method for administering nanoformulations to the brain has been examined and proven successful by prior investigators. For the treatment of central nervous system (CNS) disorders such as neuropsychiatric, depression, Alzheimer and anxiety, intranasal administration has become more popular for delivering drugs to the brain. This method offers direct transport through neuronal pathways. The lipid-based nanocarriers like nanostructured lipid carriers (NLC) appear more favorable than other nanosystems for brain administration. The nanostructured lipid carriers (NLC) system can quickly transform into a gelling system to facilitate easy administration into the nasal passages. The various compatibility studies showed that the other lipid structured-based formulations may not work well for various reasons, including a low drug filing capacity; during storage, the formulation showed changes in the solid lipid structures, which gives a chance of medication ejection. Formulations containing NLC can minimize these problems by improving drug solubility and permeation rate by incorporating a ratio of liquid lipids with solid lipids, resulting in improved stability during storage and drug bioavailability because of the higher drug loading capacity. This review aimed to find and emphasize research on lipid-based nanocarrier formulations that have advanced the treatment of central nervous system illnesses using nasal passages to reach the targeted area's drug molecules.

Non-dermal applications of microneedle drug delivery systems

Microneedles (MNs) are micron-scaled needles measuring 100 to 1000 μm that were initially explored for delivery of therapeutic agents across the skin. Considering the success in transcutaneous drug delivery, the application of microneedles has been extended to different tissues and organs. The review captures the application of microneedles to the oral mucosa, the eye, vagina, gastric mucosa, nail, scalp, and vascular tissues for delivery of vaccines, biologics, drugs, and diagnostic agents. The technology has created easy access to the poorly accessible segments of eye to facilitate delivery of monoclonal antibodies and therapeutic agents in management of neovascular disease. Microporation has been reported to drastically improve the drug delivery through the poorly permeable nail plate. Curved microneedles and spatially designed microneedle cuffs have been found to be capable of delivering stem cells and therapeutic macromolecules directly to the cardiac tissue and the vascular smooth muscle cells, respectively. Besides being minimally invasive and patient compliant, the technology has the potential to offer viable solutions to deliver drugs through impermeable barriers owing to the ability to penetrate several biological barriers. The technology has been successful to overcome the delivery hurdles and enable direct delivery of drug to the target sites, thus maximizing the efficacy thereby reducing the required dose. This review is an attempt to capture the non-dermatological applications of microneedles being explored and provides an insight on the future trends in the field of microneedle technology. Pictorial representation of different microneedle application.

Nanotechnologies for the delivery of biologicals: Historical perspective and current landscape

Biological macromolecule-based therapeutics irrupted in the pharmaceutical scene generating a great hope due to their outstanding specificity and potency. However, given their susceptibility to degradation and limited capacity to overcome biological barriers new delivery technologies had to be developed for them to reach their targets. This review aims at analyzing the historical seminal advances that shaped the development of the protein/peptide delivery field, along with the emerging technologies on the lead of the current landscape. Particularly, focus is made on technologies with a potential for transmucosal systemic delivery of protein/peptide drugs, followed by approaches for the delivery of antigens as new vaccination strategies, and formulations of biological drugs in oncology, with special emphasis on mAbs. Finally, a discussion of the key challenges the field is facing, along with an overview of prospective advances are provided.

Transmucosal posterior segmentation in the context of minimally invasive Le Fort I osteotomy: Technical note

In patients in which posterior segmentation of the maxilla is planned in the context of a minimally invasive Le Fort I osteotomy, accessing the posterior segmentation may tear the soft tissues, causing the minimally invasive approach to become lost, and tissue vascularization may be jeopardized. A technical note is presented for maintaining the original incision length when posterior osteotomies are required in the context of a minimally invasive Le Fort I osteotomy. Two vertical incisions are performed at the level of the premolars, a subperiosteal tunnel is made to access the bone with the piezoelectric device, and then an osteotome is used to complete the osteotomy. It thus may be concluded that this simple and safe additional limited approach can be reproduced in all cases where reaching an anatomical structure in the posterior maxillary region is required in the context of a minimally invasive Le Fort I osteotomy. The described technique offers easy and direct access to the posterior region of the maxilla while maintaining the initial incision length and preserving vascularization through the buccal corridors.

A pilot study on the effects of transcutaneous and transmucosal laser irradiation on blood pressure, glucose and cholesterol in women

The present pilot study had the objective to determine the effects of transcutaneous and transmucosal laser irradiation on arterial blood pressure (ABP), glucose (Glu) triglycerides (Tg), total cholesterol (Ch), high-density level cholesterol (HDL) and low-density cholesterol (LDL) immediately after treatment (T0) and after 30 (T30) and 60 (T60) days. Patients (n = 36) were selected and randomly distributed into 6 groups (n = 6/group; [G1] negative control, [G2] radial artery transcutaneous laser irradiation [G3] radial artery transcutaneous irradiation, [G4] transmucosal sublingual irradiation, [G5] transmucosal intra-nasal irradiation and [G6] extended radial artery transcutaneous irradiation). Blood exams were performed at T0, T30 and T60. Systolic and diastolic pressure results have indicated that patients' pressures ranged from 90 mmHg (P22, T30, G4) to 189 mmHg (P16, T0, G3) and 54 mmHg (P21, T60, G4) to 175 mmHg (P16, T30, G3). Levels of Glu at T30 and T60 varied from 5.53% (G1) to -5.78% (G6) and 1.21 (G2) to -8.69 (G6), respectively. Data was statistically assessed for normality and homogeneity of variances using the F-statistic and Bartlett's tests. Significant differences were determined using One-Way ANOVA and Fischer post hoc tests. Results indicated that treatments investigated can be safely used as an adjunct method to regulate blood pressure, glucose, triglycerides and cholesterol.

A crossover clinical study to evaluate pain intensity from microneedle insertion in different parts of the oral cavity

The objective of the present study was to evaluate discomfort and safety of microneedle (MN) insertion in several intraoral regions. A device was developed to standardize MN insertions. MNs were inserted in the following regions of the oral cavity: gingiva, palatine alveolar process, buccal mucosa, dorsum of the tongue and inner portion of the lower lip. Perforations from MNs post insertion were confirmed with topical gentian violet stain. Pain was evaluated in a randomized, double-blinded, crossover study in 30 volunteers. Each volunteer received a MN patch, a 30G hypodermic needle (positive control) and an identical MN patch with its needles laying flat in the plane of the patch (negative control). Adverse events were visually evaluated immediately after (0 h) and 24 h post MN application. The application device developed a consistent application force (10 N) and promoted perforation of all individual MNs on a patch. At all sites, insertion of the hypodermic needle promoted more pain when compared to the negative control (p < 0.001). Application of the MNs promoted less pain than the hypodermic needle (p < 0.05), but slightly more pain as compared to the negative control (p < 0.05) at all sites except the tongue, where the MN did not differ from the negative control (p > 0.05). Hypodermic needle caused bleeding at all insertion sites. In contrast, MNs did not cause bleeding at most sites except in some cases of insertion into the hard gingiva and the palatine alveolar process where tiny blood spots appeared immediately after MN application for few of the MNs on the patch. There were no cases of bleeding at 24 h post MN application. In conclusion, MNs can perforate different sites of the oral cavity in a safe and significantly less painful manner as compared to the 30G hypodermic needle. Thus, analogous to the skin, MN-based approaches could be an attractive approach for drug delivery in the oral cavity.

Overview of Drug Delivery Methods in Exotics, Including Their Anatomic and Physiologic Considerations

Drug delivery to exotic animals may be extrapolated from domestic animals, but some physiologic and anatomic differences complicate treatment administration. Knowing these differences enables one to choose optimal routes for drug delivery. This review provides practitioners with a detailed review of the currently reported methods used for drug delivery of various medications in the most common exotic animal species. Exotic animal peculiarities that are relevant for drug administration are discussed in the text and outlined in tables and boxes to help the reader easily find targeted information.

Transmucosal Nanoparticles: Toxicological Overview

Nanoparticles have specific physicochemical properties different to bulk materials of the same composition and such properties make them very attractive for commercial and medical applications. Mucoadhesive nanoparticulate dosage forms are designed to enable prolonged retention of these nanoparticles at the site of application, providing a controlled drug release for improved therapeutic outcome. Moreover, drug delivery across the mucosa bypasses the first-pass hepatic metabolism and avoids the degradation by gastrointestinal enzymes. However, like most new technologies, there is a rising debate concerning the possible transmucosal side effects resulting from the use of particles at the nano level. In fact, these nanoparticles on entering the body, deposit in several organs and may cause adverse biological reactions by modifying the physiochemical properties of living matter. Several investigators have found nanoparticles responsible for toxicity in different organs. In addition, the toxicity of nanoparticles also depends on whether they are persistent or cleared from the different organs of entry and whether the host can raise an effective response to sequester or dispose of the particles. In contrast to many efforts aimed at exploiting desirable properties of nanoparticles for medicine, there are limited attempts to evaluate potentially undesirable effects of these particles when administered intentionally for medical purposes. This chapter focuses on the overview of the mucosal systems, fate of nanoparticles, mechanism of nanoparticle's toxicity and the various toxicity issues associated with nanoparticles through mucosal routes.

Comparative Study of Different Combinational Mucoadhesive Formulations of Sumatriptan-Metoclopramide

PURPOSE

Sumatriptan succinate (Sum) is a Serotonin 5- HT1 receptor agonist, used in the treatment of migraine. It is absorbed rapidly but incompletely when taken orally and underwent first - pass metabolism, resulting in a low bioavailability of about 15%. The aim was to design mucoadhesive buccal discs and sublingual films of Sum and metoclopramide (Met) combined to improve their bioavailability.

METHODS

In the current study, the microparticles and films were prepared by emulsion solvent diffusion (ESD) and solvent casting methods, respectively. Buccal-mucoadhesive microparticles and films with different drug to polymer ratios were prepared and characterized by encapsulation efficiency, particle size, DSC (Differential Scanning Calorimetric), folding endurance, mucoadhesive property and drug release studies.

RESULTS

The best drug/s to polymer ratios in films and microparticles were 1:2.7:8 (SM2) and 1:4:6 (SM4), respectively. The film of SM2 showed 11.01 mg weight, 123 µm thickness and 300 folding endurance. The production yield was 107.33% for SM4 microparticles, 323.59 µm for mean particle size and 94.53% for loading efficiency (for Sum) and 104.18% (for Met). The DSC showed no stable characteristic of Sum and Met in the drug loaded films/discs and revealed amorphous form and transition of hydrate to anhydrous form for Met. The films exhibited very good mucoadhesive properties and shorter retention time (15-30 s) in comparison with the discs (130 min). The results showed that the discs prepared had slower release than the films (p<0.05).

CONCLUSION

Films and discs of Sum-Met combinations were successfully prepared with improved release and mucoadhesive properties.

Design and in vitro characterization of buccoadhesive drug delivery system of insulin

A buccoadhesive drug delivery system of Insulin was prepared by solvent casting technique and characterized in vitro by surface pH, bioadhesive strength, drug release and skin permeation studies. Sodium carboxymethylcellulose-DVP was chosen as the controlled release matrix polymer. The optimized formulation J₄ contained Sodium carboxy methyl cellulose-DVP 2% (w/v), insulin (50 IU/film), propylene glycol (0.25 ml) and Isopropyl alcohol: water (1:4) as solvent system. Bioadhesive strength of the prepared patches was measured on a modified physical balance using bovine cheek pouch as the model membrane. In vitro release studies were carried out at 37 ± 2° using phosphate buffer pH 6.6, in a modified dissolution apparatus fabricated for the purpose. Cumulative amount of drug released from the optimized formulation J₄ was 91.64% in 6 hours. In vitro permeation studies were carried out on J₄ at 37 ± 2° using Franz diffusion cell. Cumulative amount of drug permeated from J₄ was 6.63% in 6 hours. In order to enhance the permeation of protein drug, different permeation enhancers were evaluated. The results suggested that sodium deoxycholate 5% (w/v) was the best permeation enhancer among those evaluated. It enhanced the permeation of insulin from 6.63% to 10.38% over a period of 6 hours. The optimized patches were also satisfactory in terms of surface pH and bioadhesive strength. It can also be easily concluded that the system is a success as compared to the conventional formulations with respect to invasiveness, requirement of trained persons for administration and most importantly, the first pass metabolism.