Autoclave-Induced Changes in the Physicochemical Properties and Antigen Adsorption of Aluminum Adjuvants

Aluminum hydroxide adjuvants are widely used in human vaccines, such as diphtheria, tetanus, hepatitis A and hepatitis B vaccines. The adsorption of antigens on aluminum hydroxide adjuvants determines the immune boosting effect of vaccines, but it is not clear how changes in physicochemical properties resulting from the production and formulation processes affect the adsorption of aluminum hydroxide adjuvants with antigens. In this study, the commercial aluminum hydroxide adjuvant Alhydrogel® was pretreated by commonly used processes such as autoclaving and calcination, and the changes of aluminum hydroxide adjuvant in physicochemical properties during the treatment were then comprehensively characterized. The adsorption of ovalbumin (OVA) with treated Alhydrogel®, was also investigated, it was found that the decrease in specific surface area caused by the autoclaving process reduced the adsorptive capacity of the antigen, and the adsorptive strength of antigen was decreased only when the surface hydroxyl groups and chemically bound water of adjuvant were reduced by calcination. These findings help to optimize the production and formulation process of adjuvants for the rational regulation of antigen adsorption in vaccines.

Novel N-Substituted 3-Aryl-4-(diethoxyphosphoryl)azetidin-2-ones as Antibiotic Enhancers and Antiviral Agents in Search for a Successful Treatment of Complex Infections

A novel series of N-substituted cis- and trans-3-aryl-4-(diethoxyphosphoryl)azetidin-2-ones were synthesized by the Kinugasa reaction of N-methyl- or N-benzyl-(diethyoxyphosphoryl)nitrone and selected aryl alkynes. Stereochemistry of diastereoisomeric adducts was established based on vicinal H3–H4 coupling constants in azetidin-2-one ring. All the obtained azetidin-2-ones were evaluated for the antiviral activity against a broad range of DNA and RNA viruses. Azetidin-2-one trans-11f showed moderate inhibitory activity against human coronavirus (229E) with EC₅₀ = 45 µM. The other isomer cis-11f was active against influenza A virus H1N1 subtype (EC₅₀ = 12 µM by visual CPE score; EC₅₀ = 8.3 µM by TMS score; MCC > 100 µM, CC₅₀ = 39.9 µM). Several azetidin-2-ones 10 and 11 were tested for their cytostatic activity toward nine cancerous cell lines and several of them appeared slightly active for Capan-1, Hap1 and HCT-116 cells values of IC₅₀ in the range 14.5–97.9 µM. Compound trans-11f was identified as adjuvant of oxacillin with significant ability to enhance the efficacy of this antibiotic toward the highly resistant S. aureus strain HEMSA 5. Docking and molecular dynamics simulations showed that enantiomer (3R,4S)-11f can be responsible for the promising activity due to the potency in displacing oxacillin at β-lactamase, thus protecting the antibiotic from undesirable biotransformation.

Repurposing primaquine as a polyamine conjugate to become an antibiotic adjuvant

In our search for new antibiotic adjuvants as a novel strategy to deal with the emergence of multi-drug resistant (MDR) bacteria, a series of succinylprimaquine-polyamine (SPQ-PA) conjugates and derivatives of a cationic amphiphilic nature have been prepared. Evaluation of these primaquine conjugates for intrinsic antimicrobial properties and the ability to restore the antibiotic activity of doxycycline identified two derivatives, SPQ-PA3-8-3 and SPQ-PA3-10-3 that exhibited intrinsic activity against the Gram-positive bacteria Staphylococcus aureus and the yeast Cryptococcus neoformans. None of the analogues were active against the Gram-negative bacterium Pseudomonas aeruginosa. However, in the presence of a sub-therapeutic amount of doxycycline (4.5 µM), both SPQ-PA3-4-3 and SPQ-PA3-10-3 compounds displayed potent antibiotic adjuvant properties against P. aeruginosa, with MIC's of 6.25 µM. A series of derivatives were prepared to investigate the structure-activity relationship that explored the influence of both a simplified aryl lipophilic substituent and variation of the length of the polyamine scaffold on observed intrinsic antimicrobial properties and the ability to potentiate the action of doxycycline against P. aeruginosa.

Pharmacodynamic and pharmacokinetic interactions of hydroalcoholic leaf extract of Centella asiatica with valproate and phenytoin in experimental models of epilepsy in rats

ETHNOPHARMACOLOGICAL RELEVANCE

Centella asiatica (CA) is commonly used herbal medicine for treatment of epilepsy. CA has CYP2C9, CYP2D6 and CYP3A4 enzymes inhibition property and used as an adjuvant therapy with conventional antiepileptic drugs (AEDs). That may be responsible for herb-drug interaction.

AIM OF THE STUDY

The present study was planned to evaluate interactions profile of hydroalcoholic extract Centella asiatica (HECA) with antiepileptic drugs in experimental models of epilepsy in rats.

MATERIALS AND METHODS

Wistar rats (175-200 g) were used. In the pharmacodynamic interaction study, seizures were induced using pentylenetetrazole (PTZ) (60 mg/kg, i.p.) and maximal electroshock seizure (MES) (70 mA for 0.2 s). The therapeutic and sub-therapeutic doses of valproate (VPA) and phenytoin (PHT) were co-administrated with HECA in PTZ and MES model of seizures respectively. Behavioural parameters were assessed using elevated plus maze test and passive avoidance paradigm. Rat brain oxidative stress parameters were also assessed. In the pharmacokinetic interaction study, the serum levels of the VPA and PHT were estimated at different time intervals by HPLC and pharmacokinetic parameters were analyzed by WinNonlin software.

RESULTS

The VPA and PHT produced complete protection against seizures in their therapeutic doses but not with sub-therapeutic doses. However, co-administration of HECA with a sub-therapeutic dose of VPA and PHT enhanced the protection of seizures and significantly (p < 0.001) attenuated the seizure induced oxidative stress and cognitive impairment. It also significantly increased (p < 0.001) serum levels of VPA and PHT. The alterations in pharmacokinetic parameters (maximum serum concentration, area under the curve, clearance) of AEDs were also found with co-administration of HECA.

CONCLUSION

The results suggested that co-administration of HECA could improve the therapeutic efficacy of VPA and PHT. But, alteration in pharmacokinetic parameters revel that needs critical medical supervision to avoid any toxic reactions.

Rp-HPLC Determination of Quercetin in a Novel D-α-Tocopherol Polyethylene Glycol 1000 Succinate Based SNEDDS Formulation: Pharmacokinetics in Rat Plasma

Despite its proven efficacy in diverse metabolic disorders, quercetin (QU) for clinical use is still limited because of its low bioavailability. D-α-Tocopherol polyethylene glycol 1000 succinate (TPGS) is approved as a safe pharmaceutical adjuvant with marked antioxidant and anti-inflammatory activities. In the current study, several QU-loaded self-nanoemulsifying drug delivery systems (SNEDDS) were investigated to improve QU bioavailability. A reversed phase high performance liquid chromatography (RP-HPLC) method was developed, for the first time, as a simple and sensitive technique for pharmacokinetic studies of QU in the presence of TPGS SNEDDS formula in rat plasma. The analyses were performed on a Xterra C₁₈ column (4.6 × 100 mm, 5 µm) and UV detection at 280 nm. The analytes were separated by a gradient system of methanol and phosphate buffer of pH 3. The developed RP-HPLC method showed low limit of detection (LODs) of 7.65 and 22.09 ng/mL and LOQs of 23.19 and 66.96 ng/mL for QU and TPGS, respectively, which allowed their determination in real rat plasma samples. The method was linear over a wide range, (30-10,000) and (100-10,000) ng/mL for QU and TPGS, respectively. The selected SNEDDS formula, containing 50% w/w TPGS, 30% polyethylene glycol 200 (PEG 200), and 20% w/w pumpkin seed oil (PSO), showed a globule size of 320 nm and -28.6 mV zeta potential. Results of the pharmacokinetic studies showed 149.8% improvement in bioavailability of QU in SNEDDS relative to its suspension. The developed HPLC method proved to be simple and sensitive for QU and TPGS simultaneous determination in rat plasma after oral administration of the new SNEDDS formula.

Dual Roles of Metal-Organic Frameworks as Nanocarriers for miRNA Delivery and Adjuvants for Chemodynamic Therapy

MicroRNA (miRNA) represents a promising class of therapeutic nucleic acid drugs, while delivery challenges remain that impede the advancement of miRNA therapy, largely because of in vivo instability and low delivery efficiency. Herein, we discover the dual roles of metal-organic framework (MOF) nanoparticles (ZIF-8) as nanocarriers for miRNA delivery and adjuvants for chemodynamic therapy. The miR-34a-m@ZIF-8 complex demonstrated efficient cellular uptake and lysosomal stimuli-responsive miRNA release. Zn²⁺ triggered the generation of reactive oxygen species, which consequently induced apoptosis of tumor cells. Released miR-34a-m led to a remarkable decrease in expression of Bcl-2 at both mRNA and protein levels and enhanced cancer cell apoptosis. In vivo experiments showed high efficacy of using miR-34a-m@ZIF-8 to suppress tumor growth via synergistic gene/chemodynamic therapy in a mouse model of triple-negative breast cancer. Our work demonstrates MOFs as a promising nanoplatform for efficient synergetic gene/chemodynamic therapy.

Preparedness against pandemic influenza: Production of an oil-in-water emulsion adjuvant in Brazil

Increasing pandemic influenza vaccine manufacturing capacity is considered strategic by WHO. Adjuvant use is key in this strategy in order to spare the vaccine doses and by increasing immune protection. We describe here the production and stability studies of a squalene based oil-in-water emulsion, adjuvant IB160, and the immune response of the H7N9 vaccine combined with IB160. To qualify the production of IB160 we produced 10 consistency lots of IB160 and the average results were: pH 6.4±0.05; squalene 48.8±.0.03 mg/ml; osmolality 47.6±6.9 mmol/kg; Z-average 157±2 nm, with polydispersity index (PDI) of 0.085±0.024 and endotoxin levels <0.5 EU/mL. The emulsion particle size was stable for at least six months at 25°C and 24 months at 4–8°C. Two doses of H7N9 vaccine formulated at 7.5 μg/dose or 15 μg/dose with adjuvant IB160 showed a significant increase of hemagglutination inhibition (HAI) titers in sera of immunized BALB/c mice when compared to control sera from animals immunized with the H7N9 antigens without adjuvant. Thus the antigen-sparing capacity of IB160 can potentially increase the production of the H7N9 pandemic vaccine and represents an important achievement for preparedness against pandemic influenza and a successful North (IDRI) to South (Butantan Institute) technology transfer for the production of the adjuvant emulsion IB160.

Structure-Function Studies on IMD-0354 Identifies Highly Active Colistin Adjuvants

Infections caused by multidrug-resistant (MDR) bacteria, particularly Gram-negative bacteria, are an escalating global health threat. Often clinicians are forced to administer the last-resort antibiotic colistin; however, colistin resistance is becoming increasingly prevalent, giving rise to the potential for a situation in which there are no treatment options for MDR Gram-negative infections. The development of adjuvants that circumvent bacterial resistance mechanisms is a promising orthogonal approach to the development of new antibiotics. We recently disclosed that the known IKK-β inhibitor IMD-0354 potently suppresses colistin resistance in several Gram-negative strains. In this study, we explore the structure-activity relationship (SAR) between the IMD-0354 scaffold and colistin resistance suppression, and identify several compounds with more potent activity than the parent against highly colistin-resistant strains of Acinetobacter baumannii and Klebsiella pneumoniae.

Organoselenium Compounds as Novel Adjuvants of Chemotherapy Drugs-A Promising Approach to Fight Cancer Drug Resistance

Malignant diseases present a serious public health burden and their treatment with traditional chemotherapy cannot be considered an all-round solution, due to toxic side effects. Selenium compounds (Se-compounds) have received substantial attention in medicinal chemistry, especially in experimental chemotherapy, both as cytotoxic agents and adjuvants in chemotherapy. A checkerboard microplate method was applied to study the drug interactions of Se-compounds and clinically relevant chemotherapeutic drugs against the multidrug-resistant (MDR) subtype of mouse t-lymphoma cells overexpressing the ABCB1 transporter. Se-compounds showed synergistic interactions with chemotherapeutic agents targeting the topoisomerase enzymes or the microtubule apparatus. The ketone-containing selenoesters showed synergism at lower concentrations (1.25 µM). Most of the tested compounds interacted antagonistically with alkylating agents and verapamil. A thiophene-containing Se-compound showed synergism with all tested drugs, except cisplatin. While the exact mechanism of drug interactions is yet unknown, the potency of the selenocompounds as efflux pump inhibitors or the potentiation of their efficacy as reactive oxygen species modulators may play a role in their complementary activity against the tested MDR lymphoma cell line.

GW779439X and Its Pyrazolopyridazine Derivatives Inhibit the Serine/Threonine Kinase Stk1 and Act As Antibiotic Adjuvants against β-Lactam-Resistant Staphylococcus aureus

As antibiotic resistance rises, there is a need for strategies such as antibiotic adjuvants to conserve already-established antibiotics. A family of bacterial kinases known as the penicillin-binding-protein and serine/threonine kinase-associated (PASTA) kinases has attracted attention as targets for antibiotic adjuvants for β-lactams. Here, we report that the pyrazolopyridazine GW779439X sensitizes methicillin-resistant Staphylococcus aureus (MRSA) to various β-lactams through inhibition of the PASTA kinase Stk1. GW779439X potentiates β-lactam activity against multiple MRSA and MSSA isolates, including the sensitization of a ceftaroline-resistant isolate to ceftaroline. In silico modeling was used to guide the synthesis of GW779439X derivatives. The presence and orientation of GW779439X's methylpiperazine moiety was crucial for robust biochemical and microbiologic activity. Taken together, our data provide a proof of concept for developing the pyrazolopyridazines as selective Stk1 inhibitors which act across S. aureus isolates.

Recent advances in experimental polyphosphazene adjuvants and their mechanisms of action

Vaccination continues to be a very important public health intervention to control infectious diseases in the world. Subunit vaccines are generally poorly immunogenic and require the addition of adjuvants to induce protective immune responses. Despite their critical role in vaccines, adjuvant mechanism of action remains poorly understood, which is a barrier to the development of new, safe and effective vaccines. In the present review, we focus on recent progress in understanding the mechanisms of action of the experimental adjuvants poly[di(carboxylatophenoxy)phosphazene] (PCPP) and poly[di(sodiumcarboxylatoethyl-phenoxy)phosphazene] (PCEP) (in this review, adjuvants PCPP and PCEP are collectively referred to as PZ denoting polyphosphazenes). PZs are high molecular weight, water-soluble, synthetic polymers that have been shown to regulate innate immune response genes, induce cytokines and chemokines secretion at the site of injection and, also, induce immune cell recruitment to the site of injection to create a local immune-competent environment. There is an evidence that as well as its role as an immunoadjuvant (that activate innate immune responses), PZ can also act as a vaccine carrier. The mechanism of action that explains how PZ leads to these effects is not known and is a barrier to the development of designer vaccines.

Intranasal glucagon for hypoglycaemia in diabetic patients. An old dream is becoming reality?

In 1983 it was shown that glucagon administered intranasally (IN) was absorbed through the nasal mucosa and increased blood glucose in healthy subjects. Shortly thereafter, it was shown that IN glucagon counteracts with hypoglycaemia in insulin-treated diabetic patients. In spite of this evidence, IN glucagon was not developed by any pharmaceutical company before 2010, when renewed interest led to intensive evaluation of a possible remedy for hypoglycaemia in insulin-treated diabetic adults and children. IN glucagon is now being developed as a needle-free device that delivers glucagon powder for treatment of severe hypoglycaemia; the ease of using this device stands in stark contrast to the difficulties encountered in use of the current intramuscular glucagon emergency kits. Studies have demonstrated the efficacy, safety and ease-of-use of this IN glucagon preparation, and suggest IN glucagon as a promising alternative to injectable glucagon for treating severe hypoglycaemia in children and adults who use insulin. This would meet the unmet medical need for an easily administered glucagon preparation.

Development and in vitro analysis of floating matrix tablets of metronidazole using Brachystegia eurycoma gum

Floating dosage forms aim to significantly increase the gastric residence time of drugs in the gastric region for several hours. Hence, this research was carried out to formulate and evaluate floating matrix tablets (FMT) of metronidazole using Brachystegia eurycoma (BE) gum as a matrix former. Floating matrix granules (FMG) were prepared by wet granulation method using the BE gum mucilage at different concentrations (2, 4, 6 and 8% w/w). Sodium bicarbonate (30%) and tartaric acid (5%) were added as the carbon (iv) oxide generating agents. Formulations were either prepared alone with the Brachystegia eurycoma or with the addition of 1.0% w/w of Eudragit RS100. All FMG were evaluated for micromeritic properties and compressed at an optimized compression pressure of 30 arbitrary unit on the tableting machine load scale. FMT were analyzed for hardness, friability, floating lag time (FLT), in vitro buoyancy test and drug release profiles. Data from the release studies were subjected to analysis by zero order flux, first order, Higuchi square root of time relationship and Korsmeyer equations. From the results obtained, all formulated FMG were flowed freely with angle of repose and Carr's index between 15.2o to 29.1o and 10 to 18% respectively. FLT for FMT was < 820 sec. The in vitro buoyancy test of FMT formulations using the BE gum mucilage alone (i.e. without the incorporation of Eudragit RS100) were <12 h while those with Eudragit RS100 were >12 h. All FMG were compressible with tablet hardness and percentage friability between 12.4-49.1 N and 0.77-0.97% respectively. There was a significant difference in tablet hardness with increase in binder concentration (p<0.05). All formulations fitted well into Higuchi model release kinetics. Formulations BE1-BE4 have their exponent values < 0.45, hence their release mechanism was by Fickian diffusion while for BE5 the exponent value was > 0.45, therefore the release mechanism for this formulation was by non Fickian diffusion. The indication is that FMT of metronidazole have been developed using BE gum mucilage as a matrix former, this can be exploited in the formulation of controlled release systems.

Effects of processing adjuvants on traditional Chinese herbs

Processing of Chinese medicines is a pharmaceutical technique that transforms medicinal raw materials into decoction pieces for use in different therapies. Various adjuvants, such as vinegar, wine, honey, and brine, are used in the processing to enhance the efficacy and reduce the toxicity of crude drugs. Proper processing is essential to ensure the quality and safety of traditional Chinese medicines (TCMs). Therefore, sound knowledge of processing principles is crucial to the standardized use of these processing adjuvants and to facilitate the production and clinical use of decoction pieces. Many scientific reports have indicated the synergistic effects of processing mechanisms on the chemistry, pharmacology, and pharmacokinetics of the active ingredients in TCMs. Under certain conditions, adjuvants change the content of active or toxic components in drugs by chemical or physical transformation, increase or decrease drug dissolution, exert their own pharmacological effects, or alter drug pharmacokinetics. This review summarizes various processing methods adopted in the last two decades, and highlights current approaches to identify the effects of processing parameters on TCMs.

Mechanisms of Antigen Adsorption Onto an Aluminum-Hydroxide Adjuvant Evaluated by High-Throughput Screening

The adsorption mechanism of antigen on aluminum adjuvant can affect antigen elution at the injection site and hence the immune response. Our aim was to evaluate adsorption onto aluminum hydroxide (AH) by ligand exchange and electrostatic interactions of model proteins and antigens, bovine serum albumin (BSA), β-casein, ovalbumin (OVA), hepatitis B surface antigen, and tetanus toxin (TT). A high-throughput screening platform was developed to measure adsorption isotherms in the presence of electrolytes and ligand exchange by a fluorescence-spectroscopy method that detects the catalysis of 6,8-difluoro-4-methylumbelliferyl phosphate by free hydroxyl groups on AH. BSA adsorption depended on predominant electrostatic interactions. Ligand exchange contributes to the adsorption of β-casein, OVA, hepatitis B surface antigen, and TT onto AH. Based on relative surface phosphophilicity and adsorption isotherms in the presence of phosphate and fluoride, the capacities of the proteins to interact with AH by ligand exchange followed the trend: OVA < β-casein < BSA < TT. This could be explained by both the content of ligands available in the protein structure for ligand exchange and the antigen's molecular weight. The high-throughput screening platform can be used to better understand the contributions of ligand exchange and electrostatic attractions governing the interactions between an antigen adsorbed onto aluminum-containing adjuvant.

Standardization of the manufacturing procedure for Pinelliae Rhizoma Praeparatum cum Zingibere et Alumine

ETHNOPHARMACOLOGICAL RELEVANCE

Pinelliae Rhizoma (PR), the dried tuber of Pinellia ternata (Thunb.) Breit., is a traditional Chinese medicinal herb. It is commonly used for treating cancer, cough and phlegm. To treat cancer, Chinese medicine practitioners often use raw PR; while to treat cough and phlegm, they usually use Pinelliae Rhizoma Praeparatum cum Zingibere et Alumine (PRZA, raw PR processed with ginger juice and alumen as adjuvant materials). Currently, the producing protocol of PRZA varies greatly among different places in China. This study aims to standardize the manufacturing procedure for PRZA. We also evaluated the impact of processing on the bioactivities and chemical profile of raw PR.

MATERIALS AND METHODS

We used the orthogonal design to optimize the manufacturing procedure of PRZA at bench scale, and validated the optimized procedure in pilot-scale production. The MTT assay was used to compare the cytotoxicities of raw PR and PRZA in hepatocellular carcinoma HepG2 cells. Animal models (ammonia liquor-induced cough model and phenol red secretion model) were used to compare the antitussive and expectorant effects of raw PR and PRZA, respectively. The chemical profiles of raw PR and PRZA samples were compared using a newly developed ultra-performance liquid chromatography/quadrupole-time-of-flight mass spectrometry (UPLC/Q-TOF-MS) method.

RESULTS

The standardized manufacturing procedure for PRZA is as follows: soak raw PR in water until the center of the cut surface is devoid of a dry core, after that, boil the herb in water (for each 100kg raw PR, 12.5kg alumen and 25L freshly squeezed ginger juice are added) for 6h, and then take out and dry them. The cytotoxicity of PRZA was less potent than that of raw PR. Intragastric administration of raw PR or PRZA demonstrated antitussive and expectorant effects in mice. These effects of PRZA were more potent than that of raw PR at the dose of 3g/kg. By comparing the chemical profiles, we found that six peaks were lower, while nine other peaks were higher in PRZA than in raw PR. Six compounds corresponding to six individual changed peaks were tentatively identified by matching with empirical molecular formulae and mass fragments.

CONCLUSION

The manufacturing procedure for PRZA was standardized. This protocol can be used for PRZA industrial production. The bioactivity assay results of raw PR and PRZA (produced using the standardized protocol) support the common practice for the clinical applications of these two decoction pieces. Moreover, raw PR and PRZA showed different chemical profiles. Further studies are warranted to establish the relationship between the alteration of chemical profiles and the changes of medicinal properties caused by processing.

Injectable micellar supramolecular hydrogel for delivery of hydrophobic anticancer drugs

In this paper, an injectable micellar supramolecular hydrogel composed of α-cyclodextrin (α-CD) and monomethoxy poly(ethylene glycol)-b-poly(ε-caplactone) (MPEG5000-PCL5000) micelles was developed by a simple method for hydrophobic anticancer drug delivery. By mixing α-CD aqueous solution and MPEG5000-PCL5000 micelles, an injectable micellar supramolecular hydrogel could be formed under mild condition due to the inclusion complexation between α-CD and MPEG segment of MPEG5000-PCL5000 micelles. The resultant supramolecular hydrogel was thereafter characterized by X-ray diffraction (XRD) and Scanning electron microscopy (SEM). The effect of α-CD amount on the gelation time, mechanical strength and thixotropic property was studied by a rheometer. Payload of hydrophobic paclitaxel (PTX) to supramolecular hydrogel was achieved by encapsulation of PTX into MPEG5000-PCL5000 micelles prior mixing with α-CD aqueous solution. In vitro release study showed that the release behavior of PTX from hydrogel could be modulated by change the α-CD amount in hydrogel. Furthermore, such supramolecular hydrogel could enhance the biological activity of encapsulated PTX compared to free PTX, as indicated by in vitro cytotoxicity assay. All these results indicated that the developed micellar supramolecular hydrogel might be a promising injectable drug delivery system for anticancer therapy.

Shenfu decoction as adjuvant therapy for improving quality of life and hepatic dysfunction in patients with symptomatic chronic heart failure

ETHNOPHARMACOLOGICAL RELEVANCE

Shenfu decoction (SFD) is a water extract of the dried root or root stalk of Panax ginseng C. A. Mey (Asian ginseng) and the lateral root of Aconitum carmichaeli Debx (prepared by Fuzi, Heishunpian in Chinese). It has been used to treat heart failure for over a thousand years. The main active components of SFD, ginsenosides and higenamine, enhance heart contractility, increase the coronary blood supply, improve ischemic myocardial metabolism, scavenge free radicals and protect myocardial ultrastructure.

AIM OF THE STUDY

To investigate the effect of SFD on quality of life (QOL) and hepatic function in symptomatic chronic heart failure (CHF) patients.

MATERIALS AND METHODS

Forty patients enrolled in the study were randomized into two groups: an SFD group (18 cases) and a control group (22 cases). All the patients received standard heart failure therapy, and the SFD group patients were also treated with Shenfu granules for 14 days as an adjunctive therapy. The effects of SFD on QOL, plasma alanine aminotransferase (ALT) level, cardiac function, left ventricular ejection fraction (LVEF) and tumor necrosis factor-α (TNF-α) level were studied. ALT threshold in hepatic injury are 21U/L for men and 17U/L for women.

RESULTS

Minnesota Living with Heart Failure Questionnaire (MLHFQ) scores were improved by 35.27±10.72 vs. 23.87±11.96 in the SFD and control groups respectively (p<0.01). Subgroup analysis of the MLHFQ results demonstrated that both physical and emotional scores were significantly higher in the SFD group (21.00±5.66 vs. 16.75±6.25, p<0.05; 4.64±4.84 vs. 1.13±2.85, p<0.05). Circulating ALT was significantly decreased by SFD (13.3IU/L vs. 0.6IU/L, p<0.01). The grading of cardiac function and LVEF were increased by 1.6±0.5 vs. 1.1±0.3 and 18%±13% vs. 8%±8% in the SFD and control groups respectively (p<0.05 and p<0.05). The level of TNF-α declined more in SFD than control group (64.8±5.0 to 57.6±4.1, p<0.05; vs. 61.6±5.9 vs. 57.7±3.2. p>0.05).

CONCLUSION

Compared with standard heart failure treatment, oral SFD as an adjuvant therapy significantly improved QOL and hepatic injury in CHF patients.

Immunopotentiator-Loaded Polymeric Microparticles as Robust Adjuvant to Improve Vaccine Efficacy

PURPOSE

Adjuvants are required to ensure the efficacy of subunit vaccines. Incorporating molecular immunopotentiators within particles could overcome drawbacks of molecular adjuvants (such as solubility and toxicity), and improve adjuvanticity of particles, achieving stronger adjuvant activity. Aim of this study is to evaluate the adjuvanticity of immunopotentiator-loaded polymeric particles for subunit vaccine.

METHODS

PLGA microparticles (PMPs) and imiquimod (TLR-7 ligand)-loaded PLGA microparticles (IPMPs) were prepared by SPG premix membrane emulsification. In vitro and in vivo studies were performed to their adjuvant activity, using ovalbumin and H5N1 influenza split vaccine as antigens.

RESULTS

Incorporating imiquimod into microparticles significantly improved the efficacy of PLGA microparticles in activating BMDCs and pMΦs, and antigen uptake by pMΦs was also promoted. IPMPs showed stronger adjuvanticity to augment OVA-specific immune responses than PMPs. IgG subclass profiles and cytokine secretion levels by splenocytes indicated that IPMPs elicited more Th1-polarized immune response, compared to PMPs. In vivo study using H5N1 influenza split vaccine as antigen also confirmed the effects of IPMPs on antigen-specific cellular immunity.

CONCLUSIONS

Considering adjuvanticity and safety profiles (PLGA and IMQ, both approved by FDA), we conclude that IMQ-loaded PLGA microparticles are promising robust adjuvant for subunit vaccines.

Encapsulation and modified-release of thymol from oral microparticles as adjuvant or substitute to current medications

The aim of this study was to encapsulate, thymol, in natural polymers in order to obtain (i) taste masking effect and, then, enhancing its palatability and (ii) two formulations for systemic and local delivery of herbal drug as adjuvants or substitutes to current medications to prevent and treat several human and animal diseases. Microspheres based on methylcellulose or hydroxypropyl methylcellulose phthalate (HPMCP) were prepared by spray drying technique. Microparticles were in vitro characterized in terms of yield of production, drug content and encapsulation efficiency, particle size, morphology and drug release. Both formulations were in vivo orally administered and pharmacokinetic analysis was carried out. The polymers used affect the release and, then, the pharmacokinetic profile of thymol. Encapsulation into methylcellulose microspheres leads to short half/life but bioavailability remarkably increases compared to the free thymol. In contrast, enteric formulation based on HPMCP shows very limited systemic absorption. These formulations could be proposed as alternative or adjuvants for controlling pathogen infections in human or animal. In particular, methylcellulose microspheres can be used for thymol systemic administration at low doses and HPMCP particles for local treatment of intestinal infections.

Atrazine degradation in soil: effects of adjuvants and a comparison of three mathematical models

BACKGROUND

There are few reports on the effects of spray adjuvants on pesticide persistence. The role of three adjuvants used with atrazine on the herbicide's degradation in soil was examined. Three mathematical models were used to describe pesticide disappearance from soil: pseudo-first-order kinetics, the non-linear Gustafson-Holden model and the biexponential function.

RESULTS

A mixture of atrazine with Atpolan 80 EC significantly inhibited herbicide soil degradation (DT50  = 78 days), while Adpros 85 SL and Break-Thru S 240 (DT50  = 25 and 24 days respectively) had little effect (DT50  = 22 days, atrazine alone). These results suggest that adjuvant can be a factor in field persistence. DT50 values obtained using the Gustafson-Holden and biexponential models were similar. Only the biexponential model requires an iterative method.

CONCLUSION

A significant effect of one adjuvant on atrazine persistence in soil was observed. The biexponential model best described the disappearance of atrazine in the soil, as indicated by the values of R(2) and RMS and the relative concentration of the herbicide in the soil.

Stabilization of a recombinant ricin toxin A subunit vaccine through lyophilization

Lyophilization was used to prepare dry, glassy solid vaccine formulations of recombinant ricin toxin A-chain containing suspensions of colloidal aluminum hydroxide adjuvant. Four lyophilized formulations were prepared by using combinations of rapid or slow cooling during lyophilization and one of two buffers, histidine or ammonium acetate. Trehalose was used as the stabilizing excipient. Aggregation of the colloidal aluminum hydroxide suspension was reduced in formulations processed with a rapid cooling rate. Aluminum hydroxide particle size distributions, glass transition temperatures, water contents, and immunogenicities of lyophilized vaccines were independent of incubation time at 40 °C for up to 15 weeks. Mice immunized with reconstituted ricin toxin subunit A (RTA) vaccines produced RTA-specific antibodies and toxin-neutralizing antibodies (TNAs) regardless of the length of high temperature vaccine storage or the degree of aluminum adjuvant aggregation that occurred during lyophilization. In murine studies, lyophilized formulations of vaccines conferred protection against exposure to lethal doses of ricin, even after the lyophilized formulations had been stored at 40 °C for 4 weeks. A corresponding liquid formulation of vaccine stored at 40 °C elicited RTA-specific antibody titers but failed to confer immunity during a ricin challenge.

Oral drug delivery systems using chemical conjugates or physical complexes

Oral delivery of therapeutics is extremely challenging. The digestive system is designed in a way that naturally allows the degradation of proteins or peptides into small molecules prior to absorption. For systemic absorption, the intact drug molecules must traverse the impending harsh gastrointestinal environment. Technologies, such as enteric coating, with oral dosage formulation strategies have successfully provided the protection of non-peptide based therapeutics against the harsh, acidic condition of the stomach. However, these technologies showed limited success on the protection of therapeutic proteins and peptides. Importantly, inherent permeability coefficient of the therapeutics is still a major problem that has remained unresolved for decades. Addressing this issue in the context, we summarize the strategies that are developed in enhancing the intestinal permeability of a drug molecule either by modifying the intestinal epithelium or by modifying the drug itself. These modifications have been pursued by using a group of molecules that can be conjugated to the drug molecule to alter the cell permeability of the drug or mixed with the drug molecule to alter the epithelial barrier function, in order to achieve the effective drug permeation. This article will address the current trends and future perspectives of the oral delivery strategies.

How to define green adjuvants

The concept 'green adjuvants' is difficult to define. This paper formulates an answer based on two approaches. Starting from the Organisation for Economic Cooperation and Development (OECD) definition for green chemistry, production-based and environmental-impact-based definitions for green adjuvants are proposed. According to the production-based approach, adjuvants are defined as green if they are manufactured using renewable raw materials as much as possible while making efficient use of energy, preferably renewable energy. According to the environmental impact approach, adjuvants are defined as green (1) if they have a low human and environmental impact, (2) if they do not increase active ingredient environmental mobility and/or toxicity to humans and non-target organisms, (3) if they do not increase the exposure to these active substances and (4) if they lower the impact of formulated pesticides by enhancing the performance of active ingredients, thus potentially lowering the required dosage of active ingredients. Based on both approaches, a tentative definition for 'green adjuvants' is given, and future research and legislation directions are set out.

[Studies on the food allergenic proteins contained in pharmaceutical excipients]

Most drugs contain pharmaceutical excipients. These are pharmacologically inactive substances used as vehicles for the active ingredients of a medication. Some of these pharmaceutical excipients are produced from allergenic foods (e.g., milk, egg, peanut, soybean, and sesame) and removing proteins completely from such excipients is difficult. Therefore, if individuals with food allergy consume drugs containing allergenic food-derived excipients, eliminating the risk of developing specific allergic symptoms induced by them may not be possible. We determined the levels of proteins in pharmaceutical excipients and ethical drugs (inhalants and injections) by spectrophotometric analyses. The level of protein in the pharmaceutical excipient lactose in each sample was approximately 1 mg/g. In the case of oils from soybeans, peanuts, and sesame in pharmaceutical excipients, proteins were detected in the range 7-9 microg/g sample. We also determined levels of allergenic proteins in pharmaceutical excipients and ethical drugs using commercial enzyme-linked immunosorbent assay systems. The milk proteins in lactose were detected in the range 1.39-13.07 microg/g. The results of this study suggest that physicians, patients with food allergies, pharmacists, and healthcare providers must pay attention to presence of potential impurities those may cause allergic symptoms in pharmaceutical products.

Optimization on preparation condition of epimedium polysaccharide liposome and evaluation of its adjuvant activity

The aim of this strategy was to investigate whether the adjuvant activity of epimedium polysaccharide (EPS) could be further enhanced after encapsulated with liposome. In preparation of EPS liposome (EPSL) test, an orthogonal L(9) (3(4)) test design was used to optimize the preparation condition of EPSL. In adjuvant activity test, 350 14-day-old chickens were randomly assigned to 7 groups and vaccinated with Newcastle disease (ND) vaccine. Simultaneously, the chickens in experimental groups were injected with EPSL at three doses, EPS and blank liposome, respectively. The activity of lymphocytes proliferation, titer of serum antibody and concentrations of cytokines were determined. Results showed that the optimal preparation condition of EPSL was that ratio of drug to lipid, ratio of soybean phospholipid to cholesterol, ultrasonic time, and water bath temperature were 1:30, 4:1, 10 min and 40°C, respectively. EPSL could significantly enhance the immune response of ND vaccine and promote cytokines secretion, and its high dose possessed the best efficacy. These findings indicated that liposome encapsulation could significantly improve the adjuvant activity of EPS.

Effect of aluminum hydroxide adjuvant on the immunogenicity of the 2009 pandemic influenza A/H1N1 vaccine: multi-level modeling of data with repeated measures

OBJECTIVE

To evaluate the effect of the aluminum hydroxide (Al-OH) adjuvant on the 2009 pandemic influenza A/H1N1 (pH1N1) vaccine.

METHODS

In a multicenter, double-blind, randomized, placebo-controlled trial, participants received two doses of split-virion formulation containing 15 μg hemagglutinin antigen, with or without aluminum hydroxide (Al-OH). We classified the participants into six age categories (>61 years, 41-60 years, 19-40 years, 13-18 years, 8-12 years, and 3-7 years) and obtained four blood samples from each participant on days 0, 21, 35, and 42 following the first dose of immunization. We assessed vaccine immunogenicity by measuring the geometric mean titer (GMT) of hemagglutination inhibiting antibody. We used a two-level model to evaluate the fixed effect of aluminum Al-OH and other factors, accounting for repeated measures.

RESULTS

The predictions of repeated measurement on GMTs of formulations with or without Al-OH, were 80.35 and 112.72, respectively. Al-OH significantly reduced immunogenicity after controlling for time post immunization, age-group and gender.

CONCLUSION

The Al-OH adjuvant does not increase but actually reduces the immunogenicity of the split-virion pH1N1 vaccine.

Aryldiones incorporating a [1,4,5]oxadiazepane ring. Part 2: chemistry and biology of the cereal herbicide pinoxaden

BACKGROUND

Pinoxaden is a new cereal herbicide that provides outstanding levels of post-emergence activity against a broad spectrum of grass weed species for worldwide selective use in both wheat and barley.

RESULTS

Factors influencing activity and tolerance to pinoxaden were in part linked to distinct structural parts of the active ingredient. Three complementary contributions that decisively impact upon the herbicidal potency against grasses were identified: a preferred 2,6-diethyl-4-methyl aromatic substitution pattern, a dione area suitable for proherbicide formation and beneficial adjuvant effects. The uptake and translocation pattern of pinoxaden when coapplied with its tailored adjuvant were analysed by autoradiography, indicating extensive and rapid penetration, followed by effective distribution throughout the plant. Crop injury reduction on incorporation of the [1,4,5]oxadiazepane ring into the aryldione template was reinforced with safener technology. Comparative studies on the behaviour of pinoxaden applied either alone or in combination with the safener cloquintocet-mexyl demonstrated that addition of the safener resulted in significant enhancement of metabolic degradation in wheat and barley, providing excellent crop tolerance and a substantial selectivity margin without adverse effects on weed control.

CONCLUSION

The biological potential of pinoxaden and its active principle pinoxaden dione in terms of grass weed control and tolerance in cereals was fully exploited by inclusion of the safener cloquintocet-mexyl in the formulation in combination with a specific and tailor-made tank-mix adjuvant based on methylated rape seed oil.

Effect of binary and ternary solid dispersions on the in vitro dissolution and in-situ rabbit intestinal absorption of gliclazide

Solid dispersion technique is widely used to improve the dissolution rate of drugs. Most investigators relied on the in-vitro characterization and considered the enhanced dissolution as an indication of improved bioavailability. The current study investigated the effects of binary and ternary solid dispersions of gliclazide with polyethylene glycol 6000 (PEG 6000) and/or pluronic F68 (PL F68) on the dissolution of gliclazide. The study also investigated the intestinal absorption in presence of solid dispersion components. The latter employed the in-situ rabbit intestinal perfusion technique. Preparation of binary solid dispersion with PEG 6000 or PL F68 significantly enhanced the dissolution rate compared to pure drug. The ternary solid dispersion of gliclazide with both polymers resulted in rapid drug dissolution with most drug being released in the first five minutes. The intestinal perfusion indicated the possibility of complete drug absorption from the small intestine. This, together with slow dissolution of pure drug suggested that the absorption of gliclazide is dissolution rate limited. The presence of PEG 6000 did not alter the intestinal absorption but PL F68 showed a trend of enhanced intestinal absorption of the drug. Ternary solid dispersion can thus provide rapid absorption due to rapid dissolution and potential increase in intestinal permeability.

Droplet evaporation and spread on waxy and hairy leaves associated with type and concentration of adjuvants

BACKGROUND

Adjuvants can improve pesticide application efficiency and effectiveness. However, quantifications of the adjuvant-amended pesticide droplet actions on foliage, which could affect application efficiencies, are largely unknown.

RESULTS

Droplet evaporation rates and spread on waxy or hairy leaves varied greatly with the adjuvant types tested. On waxy leaves, the wetted areas of droplets containing crop oil concentrate (COC) were significantly smaller than those containing modified seed oil (MSO), non-ionic surfactant (NIS) or oil surfactant blend (OSB), whereas the evaporation rates of COC-amended droplets were significantly higher. On hairy leaves, COC-amended droplets remained on top of the hairs without wetting the epidermis. When the relative concentration was 1.50, the wetted area of droplets with NIS was 9.2 times lower than that with MSO and 6.1 times lower than that with OSB. The wetted area increased as the adjuvant concentration increased. MSO- or OSB-amended droplets spread extensively on the hairy leaf surface until they were completely dried.

CONCLUSION

These results demonstrated that the proper concentration of MSO, NIS or OSB in spray mixtures improved the homogeneity of spray coverage on both waxy and hairy leaf surfaces and could reduce pesticide use. This article is a US Government work and is in the public domain in the USA.

Inhibition of herbicide photodegradation by plant products

Pesticide reactivity toward light is rarely considered at the leaf surface after crop treatment; regardless, these degradation reactions directly impact the pesticide effectiveness. The use of sunscreen adjuvants to overcome photodegradation has presented some limitations so far. Raw hydroalcoholic plant extracts have been recently proposed to be used as photoprotecting adjuvants; on a model system they significantly decreased the photodegradation of pesticide. Here it is demonstrated that their use makes possible a dose reduction. Sulcotrione, a selective herbicide for use in maize, was tested in a growth chamber equipped with simulated solar light against a typical weed in maize. Sprayed weeds were monitored by biometrical and physiological parameters. Sulcotrione minimum dose required for a good herbicidal efficacy (ED(50), corresponding to 50% of chlorophyll content decay) was estimated to be 55 g ha(-1). In the presence of grape extract added in a 3-fold excess compared to the herbicide, the ED(50) decreased to 34 g ha(-1). The use of grape extract allows extension of sulcotrione herbicidal activity and reduction of the dose by 35% in controlled conditions. This is a promising result for the effective dose field adjustment.

Enhancing Effects of Medium Chain Aliphatic Alcohols and Esters on the Permeation of 6-Carboxyfluorescein and Indomethacin through Rat Skin

Medium chain aliphatic alcohols (C8-C12) and methyl or propyl esters of medium chain fatty acids (C8-C12) enhanced the permeation of 6-carboxyfluorescein (6-CF) and indomethacin (IND) through excised rat skin. The enhancing effects of the aliphatic alcohols for 6-CF and IND decreased with the increase in carbon chain length. The dependence on the carbon chain length was different from that exhibited by medium-chain fatty acids previously reported. In the case of fatty acid esters, the enhancing effects were lower than those of aliphatic alcohols and fatty acids. The relationship between the enhancing effects and the total number of carbon atoms in the esters was different for 6-CF and IND. The dependence on the total number of carbon atoms was similar to that in the aliphatic alcohols for 6-CF, and greater effects were observed in the shorter esters. On the other hand, no definite trends were observed for IND. Although the relationships between the structure and skin permeation-enhancing effect of the aliphatic alcohols and fatty acid esters used in this study are not yet fully understood, they are possible candidates as permeation enhancers for hydrophilic and lipophilic drugs. Further experiments, including examination of the location and environment of the lipophilic carbon chain and hydrophilic groups of such enhancers in the stratum corneum, are needed to optimize transdermal delivery systems containing them.

Characterization of microencapsulated pear ester, (2E,4Z)-ethyl-2,4-decadienoate, a kairomonal spray adjuvant against neonate codling moth larvae

Codling moth (CM), Cydia pomonella (Lepidoptera: Tortricidae), is the key pest of apples, pears, and walnuts worldwide. The pear-derived kairomone, ethyl (2E,4Z)-2,4-decadienoate, the pear ester (PE), evokes attraction and arrestment of CM larvae. Microencapsulated PE formulation (PE-MEC) enhances the control efficacy of insecticides when used as a spray adjuvant. Characterization of the microencapsulated kairomone, including microcapsule size, concentrations, emission rates, and larval response, was performed. Microcapsule diameter ranged from 2 to 14 mum, with 68% of capsules being 2-3 mum, and the concentration of microcapsules averaged 25.9 x 10(4) capsules per mL of field spray solution. Headspace collections showed emission of PE was related to PE-MEC concentration and was best described as first-order power decay. Neonate larvae responded to PE-MEC applications aged through 14 days. These results demonstrated that application of PE-MEC concurrent with insecticides may increase neonate foliar wandering, thereby disrupting host location and enhancing mortality by prolonging its exposure to insecticide.

Application of poly(acrylic acid) superporous hydrogel microparticles as a super-disintegrant in fast-disintegrating tablets

Poly(acrylic acid) superporous hydrogel (SPH) microparticles possessing a unique porous structure were used as a wicking agent to decrease disintegration time of fast-disintegrating tablets (FDTs). The compression behaviour of poly(acrylic acid) SPH microparticles was evaluated using the Kawakita equation. Effects of various SPH microparticle sizes and a 19-run fractional factorial design were evaluated. The factorial design was based on four factors consisting of ketoprofen, SPH microparticle, filler, and tableting pressure, and each factor contained three levels on the disintegration time and tensile strength of the prepared FDTs. The poly(acrylic acid) SPH microparticles existed in an amorphous state and swelled approximately 80-times in distilled water and 50-times in pH 6.8 0.2 m phosphate buffer. The compressibility of SPH microparticles increased significantly as the microparticle size increased. The FDTs made of SPH microparticles in the range of 75–106 μm showed the fastest disintegration time and higher tensile strength. SPH microparticle, tableting pressure and ketoprofen had significant effects on disintegration time and tensile strength of ketoprofen FDTs. The FDTs that were prepared with 2.5% w/w SPH microparticles of 75–106 μm at 63 MPa pressure possessed a tensile strength of 84.4+4.1 N cm−2 and disintegrated in 15.0+2.0 s. It was concluded that the poly(acrylic acid) SPH microparticles could serve as a good super-disintegrant decreasing the disintegration time of FDTs.

[Evaluation of promoting effect of several transdermal enhancers with fuzzy matter-element model]

OBJECTIVE

To investigate the utilization of fuzzy matter - element model in evaluating the promoting effects of transdermal enhancers.

METHOD

Paracetamol was used as drug model. Azone, menthol, camphor, oleic acid, clove oil, Schizonepeta tenuifolia oil and patchouli were used as transdermal enhancers. Transdermal absorption experimentation of paracetamol was detected on the device of penetrating skins of rabbit in vitro and penetrating rates, steady fluxs, lag time and enhancement ratio were calculated to evaluate promoting effects of transdermal enhancers with fuzzy matter-element model based on variation coefficient weight.

RESULT

Paracetamol had the best promoting function with 2% clove oil and 2% camphor. The function drops slightly with 1% azone, 2% Schizonepeta tenuifolia oil, 2% menthol and 2% oleic acid ranked behind. The worst was with 2% patchouli.

CONCLUSION

Fuzzy matter-element model based on variation coefficient weight could judge the promoting and penetrating effect of transdermal enhancers objectively and feasible.

[Application of thermoplastic elastomer in hot-melt pressure sensitive adhesives for transtermal drug delivery]

Development of drug dosage forms to a great extent depends on the development of drug auxiliary materials. The development of a new type of polymeric drug auxiliary materials will bring on the developing of a novel dosage forms technology and a flood of new drug dosage forms. Thermoplastic elastomer is a new type of drug polymeric auxiliary materials, at present, which has a broad application in the field of hot-melt pressure sensitive adhesives. This review mainly discussed a new transtermal Chinese drug delivery system, including matrix composition of the formula, modified thermoplastic elastomer for hot-melt pressure sensitive adhesives and their development prospects in the traditional Chinese drug delivery system. It suggested that thermoplastic elastomer of hot-melt pressure sensitive adhesives has broad development prospects in the field of the transtermal drug delivery system for traditional Chinese medicine.

Effects of optical brighteners used in biopesticide formulations on crops: reflectance, stomatal conductance, photosynthesis, and growth

Optical brighteners have attracted interest as adjuvant's in baculovirus-based biological insecticides due to their ability enhance the insecticidal properties of these viruses and protect virus particles from the degrading effects of ultraviolet (UV) radiation. The effects of two types of optical brighteners, Tinopal CBS (a distyryl-biphenyl derivative) and Tinopal C1101 (an ethenediyl benzenesulfonic derivative) at 1 or 3% (wt./vol.), on growth of different crOPs [maize, Zea mays L. (var. HY-311), sorghum, Sorghum vulgare Pers. (var. Silo), tomato, Lycopersicum esculentum L. (var. Floradade IT), or pepper, Capsicum annum L. (var. Cal Won 300)] were examined after once a week application during four weeks. Both compounds significantly affected the growth of maize plants, whereas sorghum plants were affected only at the highest concentration of Tinopal C1101. Neither brightener had negative effects on tomato or peppers plants. Both compounds increased the percentage of reflectance of maize and tomato leaves when analyzed using laboratory and field spectrophotometers. A greenhouse experiment involving single application of 1 and 3% Tinopal C1101 indicated that the stomatal conductance and photosynthetic rate of maize and tomato plants were not significantly affected. We conclude that the effects of optical brighteners on plant growth are more likely to be influenced by differences between plant species than differences between brightener compounds.

Optimization of Formulation Components and Characterization of Large Respirable Powders Containing High Therapeutic Payload

The aim of the study was to optimize and characterize high therapeutic payload large respirable powders prepared by spray-drying technique for maximum fine particle fraction with minimum quantities of excipients. Influence of formulation components was optimized by a three-factor, five-level central composite design having different proportions of L-leucine (X1), tobramycin sulfate (X2), and poloxamer-188 (X3) as the independent variables and fine particle fraction as a response variable (Y). Large respirable powders were characterized for particle size, size distribution, moisture, crystallinity, and morphology. In vitro aerosol performance of powders was determined by an eight-stage Andersen cascade impactor using the Rotahaler. Mathematical model elucidated for Y was Y = 56.2068 + 5.7481 X1 - 3.0531 X2 + 0.8468 X3 + 1.1737 X1 X2 - 0.5012 X1 X3 - 0.7412 X2 X3 - 0.7149 X1(2) - 1.9212 X2(2) - 1.6187X3(2). The component of greatest influence on product performance (response variable) was found to be L-leucine. Lack of fit was not significant (p = 0.08), and regression equation predicted response for Y was in reasonably good agreement with experimental values (p = 0.01; R2 = 0.92). The optimal model predicted with a fine particle fraction of 62.8 +/- 2.6% with X1, X2, X3 levels of 20, 45.71, and 5.51 respectively. Large respirable powders with TB load of 45.7% w/w were prepared; they had smooth surface texture, dimpled spherical shape, roundness value close to 1(1.048 +/- 0.032) and were found to possess bulk tap densities of 0.04 g/cc, geometric particle sizes of 6-7 micro m, and emitted dose of 92%. The results of the studies suggest that in vitro aerosol performance was affected significantly by small and deliberate change of specific formulation components and its proportions. It may be concluded that appropriate type and proportion of excipients is necessary to obtain maximum fine particle fraction of large respirable powders containing high therapeutic payloads.

Preparation and Evaluation of Mucin-Gelatin Mucoadhesive Microspheres for Rectal Delivery of Ceftriaxone Sodium

Soluble mucin (S-mucin) processed from the small intestines (ileal region) of freshly slaughtered pigs via homogenization, dialysis, centrifugation and lyophilization and its admixtures with type A gelatin were dispersed in an aqueous medium and used to formulate ceftriaxone sodium-loaded mucoadhesive microspheres by the emulsification cross-linking method using arachis oil as the continuous phase. The release profile of ceftriaxone sodium from the microspheres was evaluated in both simulated gastric fluid (SGF) without pepsin (pH 1.2) and simulated intestinal fluid (SIF) without pancreatin (pH 7.4). The microspheres were further evaluated as possible novel delivery system for rectal delivery of ceftriaxone sodium in rats. Release of ceftriaxone sodium from the microspheres in both release media was found to occur predominantly by diffusion following non-Fickian transport mechanism and was higher and more rapid in SIF than in SGF. The results obtained from this study may indicate that ceftriaxone sodium could be successfully delivered rectally when embedded in microspheres formulated with either type A gelatin alone or its admixtures with porcine mucin; hence providing a therapeutically viable alternative route for the delivery of this acid-labile third generation cephalosporin.

Novel oral absorption system containing polyamines and bile salts enhances drug transport via both transcellular and paracellular pathways across Caco-2 cell monolayers

The combinatorial use of spermine (SPM), a typical polyamine, and sodium taurocholate (STC), a typical bile salt, was found to be a promising safe preparation for improving the oral absorption of poorly water-soluble and/or poorly absorbable drug in our previous studies utilizing rats and dogs. To clarify the mechanisms behind the synergistic enhancement effect of the polyamine and bile salt, the transport of rebamipide, which is classified into Biopharmaceutics Classification System Class IV, was investigated in Caco-2 cell monolayers. The synergistic enhancement of rebamipide transport by SPM and STC was certainly observed in Caco-2 cells as well, while the separate use of either SPM or STC did not significantly improve the transport of rebamipide. The combinatorial use of SPM and STC significantly decreased the transepithelial electrical resistance (TEER) in Caco-2 cell monolayers, suggesting that the opening of paracellular pathway. On the other hand, it was also confirmed that the decrease in TEER was transient and reversible after removal of SPM and STC and that cell viability was maintained. Voltage-clamp study clearly showed that their combinatorial use improved rebamipide transport via both paracellular and transcellular pathways, and that the contribution of transcellular route could be larger than paracellular route.

Factors influencing the association between active ingredient and adjuvant in the leaf deposit of adjuvant-containing suspoemulsion formulations

BACKGROUND

For an oil adjuvant to enhance uptake of a particulate active ingredient (AI), it is hypothesised that closer association between the two should result in higher uptake. Accordingly, factors important for the spray deposit size on grapevine leaves have been investigated for a series of model suspoemulsion formulations containing colloidal crystalline AI or fluorescent pigment particles and an emulsion of an oil adjuvant with different degrees of wetting and different spray volumes.

RESULTS

Low spray volumes (<100 L ha(-1)) produced small deposits with high particle-adjuvant association. Complementary uptake studies showed increased uptake with decreasing deposit size, in agreement with the above hypothesis. Higher spray volumes produced larger deposits that consisted of annuli formed by pinning of the contact line by particles. Low surfactant concentrations favoured particles in the annulus and adjuvant separated in the centre. Intermediate surfactant concentrations produced annuli containing both particles and adjuvant, while with high surfactant concentrations the deposits were large with few annuli.

CONCLUSIONS

Small deposits result in high AI-adjuvant association. With larger deposits, annulus structures allow for enhanced AI-adjuvant association (5-20 times greater). The formation of annuli appears to be important in enhancing the biodelivery of particulate AIs in adjuvant-containing suspoemulsion formulations at intermediate spray volumes.

In vitro permeation of carvedilol through porcine skin: effect of vehicles and penetration enhancers

This investigation studied the effect of vehicles on the in vitro permeation of carvedilol from saturated solutions across porcine skin and selected appropriate penetration enhancers. Labrasol, Transcutol, polyethylene glycol 400, propylene glycol, ethanol, oleic acid, isopropyl myristate, and phosphate buffered saline (pH 7.4) containing 40% v/v polyethylene glycol 400 as control, were used as vehicles; limonene, carvone, camphor, menthol, Transcutol, and Labrasol at 5% w/v concentrations were used as penetration enhancers. Skin permeation studies were conducted in Franz diffusion cells using excised porcine ear skin. Solubility was highest (369.13 mg/mL) in Transcutol, whereas isopropyl myristate showed the lowest solubility (0.79 mg/mL) among all the vehicles. The flux of carvedilol from Transcutol, Labrasol, polyethylene glycol 400, ethanol, and oleic acid was 10.5, 8.6, 4.2, 2.9, and 1.5 times higher, respectively, than that observed with control. The flux obtained using Transcutol was significantly higher (P < 0.05) than the flux obtained using the other vehicles. However, the flux values of carvedilol using isopropyl myristate (P < 0.01) and propylene glycol (P < 0.05) were significantly lower than that of the control. Solutions containing 5% w/v camphor showed maximum permeation (232.54 microg) in 24 h with a flux of 3.19 microg/cm2/h, which was significantly different (P < 0.05) than the flux obtained using other permeation enhancers. The control sample showed lowest permeation (30.50 microg), with a flux of 0.33 microg/cm2/h. The flux of carvedilol from the solutions containing 5% w/v camphor, limonene, Transcutol, carvone, Labrasol, and menthol were 9.7, 7.6, 7.6, 6.3, 4.7, and 2.3 times higher, respectively, than that observed using the control. The present study suggests that Transcutol, Labrasol, and polyethylene glycol 400 may be used as potential vehicles and camphor, limonene, and Transcutol at a 5% w/v level as penetration enhancers.

[Effect of several penetration enharcers on transdermal permeation and skin accumulation of artemether]

OBJECTIVE

To investigate penetration characteristics of artemether and the effect of different permeation enhancer on transdermal permeation of artemether through rat skin.

METHOD

The permeation experiments were performed using rat skin on modified Franz diffusion cells in vitro. The concentrations of artemether in receptor compartment at specified time points were determined by HPLC.

RESULT

The permeating ratio through human skin of artemether solution was Js (2.78 +/- 0.78) microg x cm(-2) x h(-1), the quantity of drug penetrated through and accumulated in the skin by the end of the experiment were (69.07 +/- 3.01) microg x cm(-2), (58.93 +/- 3.56) microg x cm(-2) respectively. Four different permeation enhancers can improve the transdermal permeation of artemether.

CONCLUSION

Artemether have the potential to be developed to new transdermal preparation.

Influence of formulation viscosity on drug absorption following nasal application in rats

The aim of this research is to clarify the influence of the viscosity of the nasal formulation on in vivo nasal drug absorption and its mechanism using an in vitro Caco-2 system. The drug solution was made viscous by the addition of dextran (Dex). The disappearance of FITC-labeled Dextran (FD, a marker of the dosing solution) applied with control solution followed monoexponential kinetics, while FD applied with Dex solution showed biexponential elimination. The mean residence time of FD in the nasal cavity was increased with the increase in Dex concentration. The nasal absorption of acyclovir was similar in the formulation with low viscosity, increased in the formulation with moderate viscosity and markedly decreased in the formulation with high viscosity. The result from the normal Caco-2 transport study could not explain the relation of in vivo drug absorption with viscosity, while the modified Caco-2 system provided data partly reflecting the change in in vivo absorption in rats. In conclusion, the residence of the applied solution in the nasal cavity was enhanced by the addition of Dex in a viscosity-dependent manner. Moderate viscosity of the dosing solution improved the in vivo nasal absorption of acyclovir, while higher viscosity decreased it.

Thiolated chitosan: development and in vitro evaluation of an oral delivery system for acyclovir

The aim of the study was to develop a novel oral delivery system for the efflux pump substrate acyclovir (ACY) utilizing thiolated chitosan as excipient which is capable of inhibiting P-glycoprotein (P-gp). Three chitosan-4-thiobutylamidine (Chito-TBA) conjugates with increasing molecular mass (Chito-9.4kDa-TBA, Chito-150kDa-TBA and Chito-600kDa-TBA) were synthesized and permeation studies on rat intestinal mucosa and Caco-2 monolayers were performed. Additionally, tablets comprising the conjugates and ACY were tested towards their drug release behaviour. The efflux ratio (secretory P(app)/absorptive P(app)) of ACY across Caco-2 monolayers was determined to be 2.5 and in presence of 100microM verapamil 1.1 which indicates ACY as P-gp substrate. In comparison to buffer only, the transport of ACY in presence of 0.5% (m/v) unmodified chitosan, 0.5% (m/v) Chito-150kDa-TBA and 0.5% (m/v) Chito-150kDa-TBA with 0.5% (m/v) reduced glutathione (GSH), was 1.3-, 1.6- and 2.1-fold improved, respectively. Transport studies across Caco-2 monolayers showed that P-gp inhibition is dependent on the average molecular mass of thiolated chitosan showing following rank order: 0.5% (m/v) Chito-150kDa-TBA/GSH>0.5% (m/v) Chito-9.4kDa-TBA/GSH>0.5% (m/v) Chito-600kDa-TBA/GSH. The higher the molecular mass of Chito-TBA was, the more sustained was the release of ACY. Chito-150kDa-TBA/GSH might be an appropriate sustained release drug delivery system for ACY, which is able to enhance ACY transport due to efflux pump inhibition.

Synergistic effects of chemical enhancers on skin permeability: a case study of sodium lauroylsarcosinate and sorbitan monolaurate

Certain mixtures of chemicals are known to synergistically enhance skin permeability to drugs. Here, we report on the transport enhancing properties of mixtures of an anionic surfactant, sodium lauroylsarcosinate (NLS) and a non-ionic surfactant, sorbitan monolaurate (S20) in 1:1 phosphate buffered saline (PBS):ethanol (EtOH) solvent. Effect of 44 different compositions of NLS:S20 on skin constituents was probed by Fourier transform-infrared (FT-IR) spectroscopy while behavior of surfactant molecules in the solvent system was probed by FT-IR and NMR spectroscopy. No aggregation of NLS or S20 alone was observed in 1:1 PBS:EtOH at all concentrations studied (0-2%, w/v). However, mixtures of NLS and S20 resulted in micelle-like aggregates at certain specific compositions. Interestingly, compositions with increased aggregation showed resemblance to those that exhibited highest skin permeabilization.

N-sulfonato-N,O-carboxymethylchitosan: A novel polymeric absorption enhancer for the oral delivery of macromolecules

Chitosan has been shown to act on the mucosal epithelial barriers mainly when protonated at acidic pH values in which it is soluble. Soluble chitosan is able to improve the permeation and absorption of neutral to cationic macromolecules only, as it forms polyelectrolyte complexes with anionic macromolecules. LMWH (Low Molecular Weight Heparin) is an anionic polysaccharide finding clinical application as an improved antithrombotic agent compared to Unfractionated Heparin (UFH). In this study we have employed N-sulfonato-N,O-carboxymethylchitosan (SNOCC) as a potential intestinal absorption enhancer of LMWH, Reviparin. SNOCC was prepared at 3 different viscosity grades 20, 40 and 60 cps and identified as SNOCC-20, SNOCC-40 and SNOCC-60, respectively. SNOCC materials were tested in vitro for their ability to decrease the Trans Epithelial Electrical Resistance (TEER) of Caco-2 cell monolayers. They were further tested as transport enhancers of hydrophilic compounds such as (14)C-mannitol, FITC-Dextran (MW 4400 Da) and Reviparin (LMWH). Solutions of Reviparin, with or without SNOCC, were administered intraduodenally in vivo in rats and the absorption of the drug was assessed by measuring the Anti-Xa levels in rat plasma. In vitro studies showed that SNOCC materials were able to induce a concentration dependent decrease in the TEER of the Caco-2 monolayers. SNOCC-40 and -60 were shown to decrease resistance more readily compared to the low viscosity SNOCC-20. (14)C-mannitol permeation data across intestinal epithelia were in agreement with the observed decrease in TEER; the higher viscosity SNOCC-60 was the most effective demonstrating a 51-fold enhancement of the permeation of the radiolabeled marker. Studies with both FITC-Dextran and Reviparin demonstrated significantly increased permeation across Caco-2 cell monolayers when they were co-incubated at the apical side of the monolayer. Intestinal absorption of Reviparin in rats was increased when it was co-administered with SNOCC-40 and -60, in agreement with in vitro data. Anti-Xa levels were elevated to and above the antithrombotic levels and were sustained for at least 6 h, giving an 18.5-fold increase in the AUC of LMWH in rats. In conclusion, SNOCC-40 and -60 have been shown to enhance both permeation and absorption of Reviparin across intestinal epithelia proving their potential as polymeric absorption enhancers.

Assessment of priority pesticides, degradation products, and pesticide adjuvants in groundwaters and top soils from agricultural areas of the Ebro river basin

Gas chromatography-mass spectrometry (GC/MS) was employed for the determination of 30 widely used pesticides including various transformation products and alkylphenols in water and agricultural soils with the aim of assessing the impact of these compounds in agricultural soils and the underlying aquifer. The extraction, clean-up, and analytical procedures were optimized for both water and soil samples to provide a highly robust method capable of determining target analytes at the ppb-ppt level with high precision. For water samples, different solid-phase extraction cartridges and conditions were optimized; similarly, pressurized liquid extraction conditions were tested to provide interference-free extracts and high sensitivity. Instrumental LODs of 3-4 pg were obtained. The multi-residue extraction procedures were applied to the analysis of groundwaters and agricultural soils from the Ebro river basin (NE Spain). Most ubiquitous herbicides detected were triazines but some acetanilides and organophosphorus pesticides were also found; the pesticide additive tributylphosphate was found in all water samples. Levels varied between 0.57 and 5.37 microg/L in groundwater, whereas nonylphenol was the sole compound detected in soil. Alkylphenols are used as adjuvants in pesticide formulations and are present in sludges employed as soil fertilizers. Occurrence was found to be similar to other environmental studies.

Particulate Systems as Adjuvants and Carriers for Peptide and Protein Antigens

The most common feature for antigen-delivery systems is their particulate nature. Together with a certain depot effect, it is the particulate nature that primarily dictates whether the antigen-delivery system will be successful in inducing a certain type and strength of immune response. In this article, we will summarize recent data on particulate delivery systems for peptide and protein antigens with a main focus on lipid or polymer-based particles, all of which possess high potential as both preventive and therapeutic vaccines for parenteral, nasal, and possibly oral administration.

Current developments using emerging transdermal technologies in physical enhancement methods

Transdermal drug delivery using patches offers many advantages, but is limited primarily by the stratum corneum barrier. Amongst the various methods to overcome this barrier, physical methods are gaining in popularity and commercial devices development. Macroflux, MTS and Silex are based on microporation, involving use of microneedles that pierce thereby bypassing the stratum corneum. Intraject , Powderject and Helios are based on needleless jet injectors wherein very fine, solid particulate drug, is fired directly into the skin, using high-pressure gas. Med- Tats incorporate use of modified drug-containing tattoos, which bind to the skin, wherein the drug is absorbed. CHADD is based on use of heat, which increases skin - permeation of drugs. High-power, pulsed lasers transmit positive mechanical forces to the skin and create intercellular channels into the skin transiently. Sonophoresis involves use of ultrasound, which transiently disrupts the stratum corneum barrier. This technique offers a non-invasive transdermal extraction of interstitial fluids of sampling body fluids. Modified Liposomes include Ethosomes (containing alcohol) and Transferosomes (containing surfactants), which have enhanced skin permeability. Pulsed magnetic fields may create transient pores in cell membranes, including skin, resulting in increased permeation. Iontophoresis is based on application of electric potential for enhancing the movement of substances to and from the body. Dupel, Ionzyme, Liposite, ETrans, Phoresor and Drionic are based on iontophoresis. GlucoWatch offers non-invasive blood glucose monitoring, based on reverse iontophoresis. This review outlines recent commercial developments in physical transdermal drug delivery technology and the specific devices and applications being targeted by the pharmaceutical industry.