Targeted DPPC/DMPG surface-modified voriconazole lipid nanoparticles control invasive pulmonary aspergillosis in immunocompromised population: in-vitro and in-vivo assessment

Invasive pulmonary aspergillosis (IPA) is the most devastating Aspergillus-related lung disease. Voriconazole (VRZ) is the first-line treatment against IPA. Despite availability in oral and parenteral dosage forms, risks of systemic toxicity dictate alternative pulmonary administration. Inspired by natural lung surfactants, dipalmitoylphosphatidylcholine/dimyristoylphosphatidylglycerol (DPPC/DMPG) surface-modified lipid nanoparticles (LNPs) were scrutinized for pulmonary administration. DPPC/DMPG-VRZ-LNPs prepared using ultrasonication/thin film hydration were investigated for colloidal properties over 3-month shelf storage. They were stable with a slight change in entrapment efficiency. They provided a sustained VRZ release over 24 h, with a rapid initial release. In vitro aerosolization indicated higher percentages of VRZ deposited on stages corresponding to secondary bronchi and alveolar ducts. Moreover, intrapulmonary administration maintained high lung VRZ concentration (27 ± 1.14 µg/g) after 6 h. A preclinical study using a cyclophosphamide-induced neutropenic rat model demonstrated a 3-fold reduction in BALF-Galactomannan down to 0.515 ± 0.22 µg/L confirming DPPC/DMPG-VRZ-LNPs potential in hyphal growth inhibition. Histopathological examination of infected/nontreated lung sections exhibited dense fungal load inside alveoli and blood vessels indicating massive tissue and angio-invasiveness. Nevertheless, DPPC/DMPG-VRZ-LNPs-treated animals displayed minimal hyphae with no signs of invasiveness. The developed bioinspired nanoparticles serve as prospective bioactive nanocarrier candidates for pulmonary administration of VRZ in the management of IPA.

Formulation strategies for achieving high delivery efficiency of thymoquinone-containing Nigella sativa extract to the colon based on oral alginate microcapsules for treatment of inflammatory bowel disease

Nigella sativa extract (NSE) was incorporated in alginate microcapsules using aerosolisation and homogenisation methods, respectively, with the aim of delivering high concentrations of the active species, thymoquinone (TQ), directly to sites of inflammation in the colon following oral administration. Encapsulation of NSE was accomplished either by direct loading or diffusion into blank microparticles. Microcapsules in the size range 40-60 µm exhibited significantly higher NSE loading up to 42% w/w and encapsulation efficiency (EE) up to 63% when the extract was entrapped by direct encapsulation compared with 4.1 w/w loading, 6.2% EE when NSE was incorporated by diffusion loading. Sequential exposure of samples to simulated intestinal fluids (SIFs) revealed that the microcapsules suppressed NSE release in simulated gastric fluid (SGF) for 2 h and SIF for 4 h and liberated most of the NSE content (80%) in simulated colonic fluid (SCF) over 18 h. NSE released in SCF at 12 h exhibited antioxidant activity, when measured using the 1,1-diphenyl-2-picryl-hydrazyl (DPPH) assay at levels comparable with the activity of unencapsulated extract. These findings demonstrate the potential of oral alginate microcapsules as highly efficient, targeted carriers for colonic delivery of NSE in the treatment of inflammatory bowel disease.

Gelucire-Based Nanoparticles for Curcumin Targeting to Oral Mucosa: Preparation, Characterization, and Antimicrobial Activity Assessment

The purpose of the study was to prepare and characterize curcumin (Cur) solid lipid nanoparticles (CurSLN) with a high-loading capacity and chemical stability for the treatment of oral mucosal infection. CurSLN were formulated using different lipids, namely, Gelucire 39/01, Gelucire 50/13, Precirol, Compritol, and poloxamer 407 as a surfactant. Formulae were evaluated for their entrapment efficiency, particle size, and ex vivo mucoadhesion test. Microbiological evaluation was carried out on six microorganisms, five of which are the most commonly affecting oral cavity in terms of determination of minimum inhibitory concentration (MIC), and minimum bactericidal concentration. Transmission electron microscopy was conducted for ultrathin section for Candida albicans-treated with formulated Cur. The results showed high entrapment efficiency and stability enhancement for Cur powder. Significant amount of Cur was retained onto the mucosal tissue indicating preferential mucosal uptake. CurSLN showed higher antimicrobial activity as compared with Cur raw material and chemically stabilized Cur where it showed MIC (0.185, 0.09375, 0.75, 3, 1.5, and 0.1875 mg/mL) against Staphylococcus aureus, Streptococcus mutans, Viridansstrept, Escherichia coli, Lactobacillus acidophilus, and Candida albicans, respectively. The prepared lipid nanoparticles maintained Cur chemical stability and microbiological activity. The lack of local antimicrobial therapeutics with minimum side effects augments the importance of studying natural products for this purpose.

A new approach for treatment of precancerous lesions with curcumin solid-lipid nanoparticle-loaded gels: in vitro and clinical evaluation

OBJECTIVE

Preparation and characterization of curcumin solid-lipid nanoparticle (CurSLN)-loaded mucoadhesive gel for local treatment of oral precancerous lesions with low dose.

METHODOLOGY

The formulated CurSLNs were dispersed in a mucoadhesive gel matrix to be applied to the buccal mucosa. Conventional mucoadhesive gel using binary system was adopted. The prepared gels were evaluated for in vitro drug dialysis, ex vivo mucoadhesion test and ex vivo permeation study using chicken buccal mucosa. Short-term clinical evaluation was carried out on 10 patients suffering oral erythroplakia in terms of pain index and lesion size measurement. (1) RESULTS: The results showed that the loaded gel with CurSLN showed good mucoadhesion property and 25 min in vivo residence time. In addition to stability enhancement for the Cur powder. All formulae did not show any drug permeated, however, significant amount of Cur was retained within the chicken buccal mucosal tissue confirmed by histological examination. Significant reduction in pain, and complete healing was observed after 6 weeks of treatment.

CONCLUSION

The local use of Cur in low dose is a promising option for treatment of precancerous lesions. The lack of local anti-inflammatory compounds with reduced side effects intensifies the importance of studying natural products for this purpose.

Lecithin-based nanostructured gels for skin delivery: an update on state of art and recent applications

Conventional carriers for skin delivery encounter obstacles of drug leakage, scanty permeation and low entrapment efficiency. Phospholipid nanogels have recently been recognized as prominent delivery systems to circumvent such obstacles and impart easier application. The current review provides an overview on different types of lecithin nanostructured gels, with particular emphasis on liposomal versus microemulsion gelled systems. Liposomal gels investigated encompassed classic liposomal hydrogel, modified liposomal gels (e.g. Transferosomal, Ethosomal, Pro-liposomal and Phytosomal gels), Microgel in liposomes (M-i-L) and Vesicular phospholipid gel (VPG). Microemulsion gelled systems encompassed Lecithin microemulsion-based organogels (LMBGs), Pluronic lecithin organogels (PLOs) and Lecithin-stabilized microemulsion-based hydrogels. All systems were reviewed regarding matrix composition, state of art, characterization and updated applications. Different classes of lecithin nanogels exhibited crucial impact on transdermal delivery regarding drug permeation, drug loading and stability aspects. Future perspectives of this theme issue are discussed based on current laboratory studies.

Fabrication, appraisal, and transdermal permeation of sildenafil citrate-loaded nanostructured lipid carriers versus solid lipid nanoparticles

Although sildenafil citrate (SC) is used extensively for erectile dysfunction, oral delivery of SC encounters many obstacles. Furthermore, the physicochemical characteristics of this amphoteric drug are challenging for delivery system formulation and transdermal permeation. This article concerns the assessment of the potential of nanomedicine for improving SC delivery and transdermal permeation. SC-loaded nanostructured lipid carriers (NLCs) and solid lipid nanoparticles (SLNs) were fabricated using a modified high-shear homogenization technique. Nanoparticle optimization steps included particle size analysis, entrapment efficiency (EE) determination, freeze-drying and reconstitution, differential scanning calorimetry, in vitro release, stability study and high-performance liquid chromatography analysis. Transdermal permeation of the nanocarriers compared with SC suspension across human skin was assessed using a modified Franz diffusion cell assembly. Results revealed that SLNs and NLCs could be optimized in the nanometric range (180 and 100 nm, respectively) with excellent EE (96.7% and 97.5%, respectively). Nanoparticles have significantly enhanced in vitro release and transdermal permeation of SC compared with its suspensions. Furthermore, transdermal permeation of SC exhibited higher initial release from both SLN and NLC formulations followed by controlled release, with promising implications for faster onset and longer drug duration. Nanomedicines prepared exhibited excellent physical stability for the study period. Solid nanoparticles optimized in this study successfully improved SC characteristics, paving the way for an efficient topical Viagra^® product.

Maltodextrin: a novel excipient used in sugar-based orally disintegrating tablets and phase transition process

The recent challenge in orally disintegrating tablets (ODT) manufacturing encompasses the compromise between instantaneous disintegration, sufficient hardness, and standard processing equipment. The current investigation constitutes one attempt to fulfill this challenge. Maltodextrin, in the present work, was utilized as a novel excipient to prepare ODT of meclizine. Tablets were prepared by both direct compression and wet granulation techniques. The effect of maltodextrin concentrations on ODT characteristics--manifested as hardness and disintegration time--was studied. The effect of conditioning (40 degrees C and 75% relative humidity) as a post-compression treatment on ODT characteristics was also assessed. Furthermore, maltodextrin-pronounced hardening effect was investigated using differential scanning calorimetry (DSC) and X-ray analysis. Results revealed that in both techniques, rapid disintegration (30-40 s) would be achieved on the cost of tablet hardness (about 1 kg). Post-compression conditioning of tablets resulted in an increase in hardness (3 kg), while keeping rapid disintegration (30-40 s) according to guidance of the FDA for ODT. However, direct compression-conditioning technique exhibited drawbacks of long conditioning time and appearance of the so-called patch effect. These problems were, yet, absent in wet granulation-conditioning technique. DSC and X-ray analysis suggested involvement of glass-elastic deformation in maltodextrin hardening effect. High-performance liquid chromatography analysis of meclizine ODT suggested no degradation of the drug by the applied conditions of temperature and humidity. Overall results proposed that maltodextrin is a promising saccharide for production of ODT with accepted hardness-disintegration time compromise, utilizing standard processing equipment and phenomena of phase transition.

Self-nanoemulsifying drug delivery systems of tamoxifen citrate: design and optimization

Tamoxifen citrate is an antiestrogen for peroral breast cancer treatment. The drug delivery encounters problems of poor water solubility and vulnerability to enzymatic degradation in both intestine and liver. In the current study, tamoxifen citrate self-nanoemulsifying drug delivery systems (SNEDDS) were prepared in an attempt to circumvent such obstacles. Preliminary screening was carried out to select proper ingredient combinations. All surfactants screened were recognized for their bioactive aspects. Ternary phase diagrams were then constructed and an optimum system was designated. Three tamoxifen SNEDDS were then compared for optimization. The systems were assessed for robustness to dilution, globule size, cloud point, surface morphology and drug release. An optimum system composed of tamoxifen citrate (1.6%), Maisine 35-1 (16.4%), Caproyl 90 (32.8%), Cremophor RH40 (32.8%) and propylene glycol (16.4%) was selected. The system was robust to different dilution volumes and types. It possessed a mean globule size of 150 nm and a cloud point of 80 degrees C. Transmission electron microscopy demonstrated spherical particle morphology. The drug release from the selected formulation was significantly higher than other SNEDDS and drug suspension, as well. Realizing drug incorporation into an optimized nano-sized SNEDD system that encompasses a bioactive surfactant, our results proposed that the prepared system could be promising to improve oral efficacy of the tamoxifen citrate.

Alendronate PLGA microspheres with high loading efficiency for dental applications

PURPOSE

Alendronate sodium, used systemically as a bone protective agent, proved to also be effective locally in various dental bone applications. Development of alendronate-loaded microspheres with high loading efficiency for such applications would be greatly challenged by the hydrophilicity and low MW of the drug. The aim of this study was to incorporate alendronate sodium, into poly (lactide-co-glycolide) (PLGA) microspheres (MS) with high loading efficiency.

METHODS

Three multiple emulsion methods: water-in-oil-in-water (W/O/W), water-in-oil-in-oil (W/O(1)/O(2)) and solid-in-oil-in-oil (S/O(1)/O(2)) were tested. In addition to entrapment efficiency, MS were characterized for surface morphology, particle size, in vitro drug release and in vitro degradation of the polymer matrix. Alendronate microspheres with maximum drug loading and good overall in vitro performance were obtained using the W/O(1)/O(2) emulsion technique.

RESULTS

Drug release from the microspheres exhibited a triphasic release pattern over a period of 13 days, the last fast release phase being associated with more rapid degradation of the PLGA matrix.

CONCLUSIONS

Biocompatible, biodegradable PLGA microspheres incorporating alendronate sodium with high loading efficiency obtained in this study may offer promise as a delivery system for bisphosphonates in dental and probably other clinical applications.

Towards a universal dissolution medium for carbamazepine

The aim of this study was to develop a dissolution medium for assessment of various carbamazepine (CBZ) formulations with different strengths. The design of a system inhibiting transformation of the anhydrous CBZ (CBZ A) to the dihydrate form (CBZ D), with minimum surface-active properties and suitable sink was investigated. The effect of pH, different concentrations of sodium lauryl sulphate (SLS), polyvinylpyrrolidone (PVP), and methyl cellulose (MC) on dissolution rate, solubility, dissolution solubility, and polymorphic transformation of CBZ was assessed. Solution-mediated transformation of CBZ A into CBZ D was monitored using optical microscopy, Fourier transform infrared spectroscopy and differential scanning calorimetry. Results showed that different strengths (100, 200, 400 mg) of the same CBZ tablet formulation exhibited different dissolution patterns, in 1% SLS (USP system). Such differences were reduced in 0.5% SLS solution which provided sufficient sink for up to 200 mg CBZ. It was also shown that solubility of CBZ A could not be detected in the media under study (water, SGF, SIF, and SLS solutions) due to its rapid transformation into CBZ D. The use of 3% PVP solution protected CBZ A from conversion for 75 min, while 0.01% MC completely inhibited the transformation up to 24 h. Therefore, a medium consisting of 0.5% SLS and 0.01% MC was selected. The medium provided: a) protection against transformation of CBZ A to CBZ D, b) increased solubility of CBZ A (204 mg % compared to 128 mg % of CBZ D in 0.5% SLS), c) suitable sink for up to 400 mg CBZ and d) overlapping dissolution profiles of various strengths of the same CBZ formulation. The suggested system may be a step in the way of solving CBZ dissolution problems that forced the USP to specify two similar dissolution tests with two different limits for conventional 200 mg CBZ tablets.