Coated Lipidic Nanoparticles as a New Strategy for Enhancing Nose-to-Brain Delivery of a Hydrophilic Drug Molecule.

Oral Almotriptan maleate (ALM) is used in the treatment of migraine; however, due to its extreme aqueous solubility, shows poor penetration and lesser concentration in the brain thus requiring frequent oral dosing. Being flexible and lipophilic in nature, nanostructured lipid carriers (NLCs) represent a promising tool in delivering therapeutic substances to the brain. This investigation is meant to explore the capability of mucoadhesive chitosan-coated NLCs to efficiently deliver ALM to the brain through the nasal route as a non-invasive alternative route for targeting the central nervous system (CNS). D-optimal design was adopted and thirteen different formulae were prepared using hot homogenization and ultrasonication technique; where an accurate amount of the almotriptan was added to the molten lipid mixture followed by the addition of the heated aqueous phase under stirring, then the mixture was subjected to homogenization and ultrasonication. The prepared systems were then assessed for their particle size, PDI (polydispersity index), zeta potential (ZP), and entrapment efficiency (EE). The optimized selected formula; F1; composed of 50/50 Compritol/Labrafil and a co-mixture of 2:1 tween 80: Lauroglycol all coated in chitosan, showed a PS of 255 nm, PDI 0.27, ZP 34.1 mV, and 80% EE. A bi-phasic in vitro drug release pattern was obtained, enhanced mucoadhesive property and ex-vivo permeability through sheep nasal mucosa were attained. The In vivo studies performed on albino rabbits showed significantly higher Cmax results in plasma of the optimized ALM-NLC (1.54 µg/mL) compared to those of IN ALM solution (0.25 µg/mL) and ALM oral tablet market product (0.58 µg/mL). Brain Cmax were found to be 3.64 µg/mL, 0.5 µg/mL and 0.48 µg/mL for IN ALM-NLC, oral ALM market product and, IN ALM solution, respectively. Histopathological examination marked the formula as safe.

A novel praziquantel solid lipid nanoparticle formulation shows enhanced bioavailability and antischistosomal efficacy against murine S. mansoni infection.

BACKGROUND: Schistosomiasis is responsible for a considerable global disease burden. This work aimed to improve the therapeutic outcome of the only available antischistosomal drug worldwide, praziquantel (PZQ), by incorporating it into a novel carrier, "solid lipid nanoparticles (SLNs)", to enhance its solubility, bioavailability and efficacy. A simple, cost-effective method was used to prepare SLN-PZQ. RESULTS: Compared to market PZQ (M-PZQ), SLN-PZQ was more bioavailable, as denoted by higher serum concentrations in both normal and infected mice where elevated Ka, AUC0-24, Cmax, and t1/2e with a decrease in kel were demonstrated. The AUC0-24 for SLN-PZQ in normal and Schistosoma mansoni-infected groups was almost nine- and eight-fold higher, respectively, than that for M-PZQ in corresponding groups. In normal and S. mansoni-infected mice, SLN-PZQ was detectable in serum at 24 h, while M-PZQ completely vanished 8 h post-treatment. Additionally, enhanced absorption with extended residence time was recorded for SLN-PZQ. Compared to M-PZQ, SLN-PZQ revealed superior antischistosomal activity coupled with enhanced bioavailability in all treated groups where higher percentages of worm reduction were recorded with all dosages tested. This effect was especially evident at the lower dose levels. The ED95 of SLN-PZQ was 5.29-fold lower than that of M-PZQ, with a significantly higher reduction in both the hepatic and intestinal tissue egg loads of all treated groups and almost complete disappearance of immature deposited eggs (clearly evident at the low dose levels). CONCLUSIONS: SLN-PZQ demonstrated enhanced PZQ bioavailability and antischistosomal efficacy with a safe profile despite the prolonged residence in the systemic circulation.

Chitosan-Gelatin Hydrogel Crosslinked With Oxidized Sucrose for the Ocular Delivery of Timolol Maleate.

Ocular hypertension due to increased intraocular pressure is a major risk factor for the development of glaucoma. Rapid clearance and low ocular bioavailability are drawbacks of conventional ocular treatments. This requires frequent and long-term application of antiglaucoma drugs which in turn cause local side effects and are a major cause of therapeutic failure due to loss of persistence in using glaucoma therapy. In this study, a semisynthetic, biocompatible, oxidized sucrose crosslinker was developed and used in the formulation of chitosan-gelatin hydrogel for the sustained release of timolol to control ocular hypertension. The swelling properties of the hydrogel showed a strong relationship with the oxidized sucrose concentration. Mucoadhesive properties of the hydrogel were studied and the in vitro release profiles demonstrated that crosslinking with oxidized sucrose reduced the release rate of the entrapped timolol. The results of both in vitro and in vivo studies supported that the formulated hydrogel maintained the release and in turn the efficacy of timolol for a longer period of time compared to the conventional eye drops. This is expected to reduce the frequency of drug application onto the eye surface and in turn enhances patients' convenience. In conclusion, the developed formulation represents a promising platform for an effective and compliant treatment of ocular hypertension.

Mucosal co-delivery of ketorolac and lidocaine using polymeric wafers for dental application.

The current study aimed to investigate the effectiveness of a developed sodium alginate and polyvinylpyrrolidone K-25 (PVP K-25) polymeric wafer for the co-delivery of ketorolac and lidocaine to soft tissues for healing and pain control following gingivectomy. Nine ketorolac/lidocaine lyophilized wafers were formulated and assessed for their hydration capacity, mucoadhesion ability and in vitro release profile to select the optimum system for further clinical investigation. Wafer F6 containing 2:1 sodium alginate to PVP K-25 and 10% glycerol showed optimum properties and was selected for the clinical study. Twenty patients were included in the study and the ketorolac/lidocaine wafer was assessed versus a market product. Visual pain analog was evaluated daily for the first week and wound healing index was evaluated for one week, two weeks and one month following the procedure. The developed ketorolac/lidocaine polymeric wafer proved to be an effective method of reducing pain and discomfort together with enhancing wound healing following gingivectomy.

Alginate coated chitosan nanogel for the controlled topical delivery of Silver sulfadiazine.

Burn wounds environment favors the growth of micro-organisms causing delay in wound healing. The traditional treatment with antimicrobial creams offer inaccurate doses. The aim of the present study is to formulate and evaluate different silver sulfadiazine loaded nanogel formulations. A factorial design experiment was used for the identification of critical process parameters and for the optimization of the respective process conditions. The prepared drug loaded nanogels were characterized for their particle size, zeta potential, entrapment efficiency and swelling index in order to demonstrate their physicochemical properties, in addition, FTIR, TEM, SEM and in vitro release were used for characterization. The release profile of all tested nanogels showed an initial burst followed by a slow and continuous release rate. An optimum nanogel formulation was predicted by the JMP® software according to the stated prediction expressions and was composed of 0.4% sodium alginate (ALG) and 0.414% Silver sulfadiazine (SSD). The optimized formulation showed higher therapeutic efficacy in vivo when compared to market product.

Using chitosan nanoparticles as drug carriers for the development of a silver sulfadiazine wound dressing.

Burn wounds environment favors the growth of micro-organisms causing delay in wound healing. The traditional treatment with antimicrobial creams offer inaccurate doses. In the present study, a dressing coated with silver sulfadiazine (SSD) loaded chitosan nanoparticles (CSNPs) for the controlled-release of SSD into burn wound to control bacterial growth was investigated. CSNPs were formulated with different concentrations of chitosan and CM-ß-CD and loaded with SSD complexed in 1:1 molar ratio with CM-ß-CD, CSNPs were assessed for their particle size, polydispersity index, morphology and association efficiency. The formula showing the best characteristics was selected for the preparation of SSD loaded CSNPs wound dressing through a padding process with/without the use of cross-linker. The dressing was characterized for its physical properties, in addition, FTIR, X-ray, SEM and in vitro release were used for characterization. The dressing was proven effective for the inhibition of the growth of Gram positive and Gram negative bacteria as well as candida on an infected wound.

Synthesis, characterization, release kinetics and toxicity profile of drug-loaded starch nanoparticles.

The current research work focuses on the medical application of the cost-effective cross-linked starch nanoparticles, for the transdermal delivery using Diclofenac sodium (DS) as a model drug. The prepared DS-cross-linked starch nanoparticles were synthesized using nanoprecipitation technique at different concentrations of sodium tripolyphosphate (STPP) in the presence of Tween 80 as a surfactant. The resultant cross-linked starch nanoparticles loaded with DS were characterized using world-class facilities such as TEM, DLS, FT-IR, XRD, and DSc. The efficiency of DS loading was also evaluated via entrapment efficiency as well as in vitro release and histopathological study on rat skin. The optimum nanoparticles formulation selected by the JMP(®) software was the formula that composed of 5% maize starch, 57.7mg DS and 0.5% STPP and 0.4% Tween 80, with particle diameter of about 21.04nm, polydispersity index of 0.2 and zeta potential of -35.3mV. It is also worth noting that this selected formula shows an average entrapment efficiency of 95.01 and sustained DS release up to 6h. The histophathological studies using the best formula on rat skin advocate the use of designed transdermal DS loaded cross-linked starch nanoparticles as it is safe and non-irritant to rat skin. The overall results indicate that, the starch nanoparticles could be considered as a good carrier for DS drug regarding the enhancement in its controlled release and successful permeation, thus, offering a promising nanoparticulate system for the transdermal delivery non-steroidal anti-inflammatory drug (NSAID).

Praziquantel in a clay nanoformulation shows more bioavailability and higher efficacy against murine Schistosoma mansoni infection.

Consideration of existing compounds always simplifies and shortens the long and difficult process of discovering new drugs specifically for diseases of developing countries, an approach that may add to the significant potential cost savings. This study focused on improving the biological characteristics of the already-existing antischistosomal praziquantel (PZQ) by incorporating it into montmorillonite (MMT) clay as a delivery carrier to overcome its known bioavailability drawbacks. The oral bioavailability of a PZQ-MMT clay nanoformulation and its in vivo efficacy against Schistosoma mansoni were investigated. The PZQ-MMT clay nanoformulation provided a preparation with a controlled release rate, a decrease in crystallinity, and an appreciable reduction in particle size. Uninfected and infected mice treated with PZQ-MMT clay showed 3.61- and 1.96-fold and 2.16- and 1.94-fold increases, respectively, in area under the concentration-time curve from 0 to 8 h (AUC0-8) and maximum concentration of drug in serum (Cmax), with a decrease in elimination rate constant (kel) by 2.84- and 1.35-fold and increases in the absorption rate constant (ka) and half-life (t1/2e) by 2.11- and 1.51-fold and 2.86- and 1.34-fold, respectively, versus the corresponding conventional PZQ-treated groups. This improved bioavailability has been expressed in higher efficacy of the drug, where the dose necessary to kill 50% of the worms was reduced by >3-fold (PZQ 50% effective dose [ED50] was 20.25 mg/kg of body weight for PZQ-MMT clay compared to 74.07 mg/kg for conventional PZQ), with significant reduction in total tissue egg load and increase in total immature, mature, and dead eggs in most of the drug-treated groups. This formulation showed better bioavailability, enhanced antischistosomal efficacy, and a safer profile despite the longer period of residence in the systemic circulation. Although the conventional drug's toxicity was not examined, animal mortality rates were not different between groups receiving the test PZQ-clay nanoformulation and conventional PZQ.

Preparation and evaluation of warfarin-ß-cyclodextrin loaded chitosan nanoparticles for transdermal delivery.

The main objective of the present work was to prepare warfarin-ß-cyclodextrin (WAF-ß-CD) loaded chitosan (CS) nanoparticles for transdermal delivery. CS is a hydrophilic carrier therefore, to overcome the hydrophobic nature of WAF and allow its incorporation into CS nanoparticles, WAF was first complexed with ß-cyclodextrin (ß-CD). CS nanoparticles were prepared by ionotropic pre-gelation using tripolyphosphate (TPP). Morphology, size and structure characterization of nanoparticles were carried out using SEM, TEM and FTIR, respectively. Nanoparticles prepared with 3:1 CS:TPP weight ratio and 2mg/ml final CS concentration were found optimum. They possessed spherical particles (35±12nm diameter) with narrow size distribution (PDI=0.364) and 94% entrapment efficiency. The in vitro release as well as the ex vivo permeation profiles of WAF-ß-CD from the selected nanoparticle formulation were studied at different time intervals up to 8h. In vitro release of WAF-ß-CD from CS nanoparticles followed a Higuchi release profile whereas its ex vivo permeation (at pH 7.4) followed a zero order permeation profile. Results suggested that the developed WAF-ß-CD loaded CS carrier could offer a controlled and constant delivery of WAF transdermally.

Chitosan/sulfobutylether-ß-cyclodextrin nanoparticles as a potential approach for ocular drug delivery.

Development of efficient ocular delivery nanosystems remains a major challenge to achieve sustained therapeutic effect. The purpose of this work was to develop chitosan nanoparticles using sulfobutylether-ß-cyclodextrin (SBE-ß-CD) as polyanionic crosslinker and to investigate the potential of using those nanostructures as ocular drug delivery systems. Econazole nitrate (ECO) was chosen as model drug molecule. The influence of different process variables (chitosan molecular weight and the concentration of the two ionic agents) on particle size, polydispersity index, zeta potential, drug content, in vitro release and mucoadhesive properties was investigated. The results showed that the prepared nanoparticles were predominant spherical in shape having average particle diameter from 90 to 673 nm with positive zeta potential values from 22 to 33 mV and drug content values ranging from 13 to 45%. Drug release from optimized nanoparticles was controlled with approximately 50% of the original amount released over a 8h period. The release profile of nanoparticles followed a zero-order release kinetics. The optimized nanoparticles were tested for their use as ocular drug delivery systems on albino rabbits. The in vivo studies revealed that the prepared mucoadhesive nanoparticles had better ability in sustaining the antifungal effect of ECO than the ECO solution. Therefore, chitosan/SBE-ß-CD nanoparticles developed showed a promising carrier for controlled delivery of drug to the eye.