A new neolignan, 3,4-dimethoxy-3',4'-methylenedioxy-2,9-epoxy-6,7-cyclo-1,8-neolign-11-en-5(5H)-one, which has been named (+)-kunstlerone (1), together with six known alkaloids: (+)-norboldine (2), (+)-N-methylisococlaurine (3), (+)-cassythicine (4), (+)-laurotetanine (5), (+)-boldine (6) and (-)-pallidine (7), were isolated from the leaves of Beilschmiedia kunstleri. The structures were established through various spectroscopic methods notably 1D- and 2D-NMR, UV, IR and LCMS-IT-TOF. (+)- Kunstlerone (1) showed a strong antioxidant activity, with an SC(50) of 20.0 µg/mL.
Purines can be considered as the most ubiquitous and functional N-heterocyclic compounds in nature. Structural modifications of natural purines, particularly using isosteric ring systems, have been in the focus of many drug discovery programs. Fusion of 1,3,5-triazine ring with pyrrole, pyrazole, imidazole, 1,2,3-triazole or 1,2,4-triazole results in seven bicyclic heterocyclic systems isosteric to purine. Application of the isosterism concept for the development of new compounds with therapeutic potential in areas involving purinergic regulation or purine metabolism led to significant advances in medicinal chemistry of the azolo[1,3,5]triazines. These 1,3,5-triazine-based purine-like scaffolds significantly increase level of molecular diversity and allow covering chemical space in the important areas of medicinal chemistry. Some of these azolo[1,3,5]triazine systems have become privileged scaffolds in the development of inhibitors of various kinases, phosphodiesterase, xanthine oxidase, and thymidine phosphorylase, antagonists of adenosine and corticotropin-releasing hormone receptors, anticancer and antiviral agents.
Fungi are a rich source of secondary metabolites with several pharmacological activities such as antifungal, antioxidant, antibacterial and anticancer to name a few. Due to the large number of diverse structured chemical compounds they produce, fungi from the phyla Ascomycota, Basidiomycota and Muccoromycota have been intensively studied for isolation of bioactive compounds. Basidiomycetes-derived secondary metabolites are known as a promising source of antibacterial compounds with activity against Gram-positive bacteria. The continued emergence of antimicrobial resistance (AMR) poses a major challenge to patient health as it leads to higher morbidity and mortality, higher hospital-stay duration and substantial economic burden in global healthcare sector. One of the key culprits for AMR crisis is Staphylococcus aureus causing community-acquired infections as the pathogen develops resistance towards multiple antibiotics. The recent emergence of community strains of S. aureus harbouring methicillin-resistant (MRSA), vancomycin-intermediate (VISA) and vancomycin-resistant (VRSA) genes associated with increased virulence is challenging. Despite the few significant developments in antibiotic research, successful MRSA therapeutic options are still needed to reduce the use of scanty and expensive second-line treatments. This paper provides an overview of findings from various studies on antibacterial secondary metabolites from basidiomycetes, with a special focus on antistaphylococcal activity.
The field of pharmaceutical technology is expanding rapidly because of the increasing number of drug delivery options. Successful drug delivery is influenced by multiple factors, one of which is the appropriate identification of materials for research and engineering of new drug delivery systems. Bacterial cellulose (BC) is one such biopolymer that fulfils the criteria for consideration as a drug delivery material.
Pyrrolothiazolyloxindole analogues share vital pharmacological properties, considered useful in Alzheimer's disease (AD). The aim of this study was synthesis and evaluate pyralothiazolyloxindole analogues if possess acetyl cholinesterase (AChE) inhibitory activity. The easily accessible one-pot synthesis of these compounds resulted to be significantly less difficult and expensive than that of donepezil. Several compounds possess anti-cholinesterase activity in the order of micro and sub-micromolar. Particularly, compound was the most potent inhibitors of the series against acetyl cholinesterase enzyme with IC(50) 0.11μmol/L.
This study was aimed to enhance the dissolution rate, oral bioavailability and analgesic potential of the aceclofenac (AC) in the form of nanosuspension using cost-effective simple precipitation-ultrasonication approach. The nanocrystals were produced using the optimum conditions investigated for AC. The minimum particle size (PS) and polydispersity index was found to be 112±2.01 nm and 0.165, respectively, using hydroxypropyl methylcellulose (1%, w/w), polyvinylpyrrolidone K30 (1%, w/w) and sodium lauryl sulfate (0.12%, w/w). The characterization of AC was performed using zeta sizer, scanning electron microscopy, transmission electron microscopy, powder X-ray diffraction and differential scanning calorimetry. The saturation solubility of the AC nanocrystals was substantially increased 2.6- and 4.5-fold compared to its unprocessed active pharmaceutical ingredient in stabilizer solution and unprocessed drug. Similarly, the dissolution rate of the AC nanocrystals was substantially enhanced compared to its other counterpart. The results showed that >88% of AC nanocrystals were dissolved in first 10 min compared to unprocessed AC (8.38%), microsuspension (66.65%) and its marketed tablets (17.65%). The in vivo studies of the produced stabilized nanosuspension demonstrated that the Cmax were 4.98- and 2.80-fold while area under curve from time of administration to 24 h (AUC0→24 h) were found 3.88- and 2.10-fold greater when compared with unprocessed drug and its marketed formulation, respectively. The improved antinociceptive activity of AC nanocrystals was shown at much lower doses as compared to unprocessed drug, which is purely because of nanonization which may be attributed to improved solubility and dissolution rate of AC, ultimately resulting in its faster rate of absorption.
Alginate-based bipolymeric-nanobioceramic composite matrices for sustained drug release were developed through incorporation of nano-hydroxyapatite [nHAp] powders within ionotropically-gelled calcium ion-induced alginate-poly (vinyl pyrrolidone) blends polymeric systems. nHAp powders were synthesized by precipitation technique using calcium hydroxide [Ca(OH)2] and orthophosphoric acid [H3PO4] as raw materials. The average particle size of these was synthesized. nHAp powders was found as 19.04 nm and used to prepare nHAp-alginate-PVP beads containing DS. These beads exhibited drug entrapment efficiency (%) of 65.82±1.88 to 94.45±3.72% and average bead sizes of 0.98±0.07 to 1.23±0.15 mm. These beads were characterized by scanning electron microscopy (SEM) and Fourier transform-infra red (FTIR) spectroscopy analyses. Various nHAp-alginate-PVP beads containing DS exhibited prolonged sustained drug release and followed the Koresmeyer-Peppas model of drug release (R2=0.9908-0.9978) with non-Fickian release (anomalous transport) mechanism (n=0.73-0.84) for drug release over 8 h.
The drawbacks associated with chemical skin permeation enhancers such as skin irritation and toxicity necessitated the research to focus on potential permeation enhancers with a perceived lower toxicity. Crude palm oil (CPO) is obtained by direct compression of the mesocarp of the fruit of the oil palm belonging to the genus Elaeis. In this research, CPO and tocotrienol-rich fraction (TRF) of palm oil were evaluated for the first time as skin permeation enhancers using full-thickness human skin. The in vitro permeation experiments were conducted using excised human skin mounted in static upright 'Franz-type' diffusion cells. The drugs selected to evaluate the enhancing effects of these palm oil derivatives were 5-fluorouracil, lidocaine and ibuprofen: compounds covering a wide range of Log p values. It was demonstrated that CPO and TRF were capable of enhancing the percutaneous permeation of drugs across full-thickness human skin in vitro. Both TRF and CPO were shown to significantly enhance the permeation of ibuprofen with flux values of 30.6 µg/cm2 h and 23.0 µg/cm2 h respectively, compared to the control with a flux of 16.2 µg/cm2 h. The outcome of this research opens further scope for investigation on the transdermal penetration enhancement activity of pure compounds derived from palm oil.
Controlled-release grade hydroxypropylmethylcellulose (HPMC) or xanthan gum (XG) and microcrystalline cellulose (MCC) were employed to prepare controlled-release diltiazem hydrochloride tablets. The similarity factor f2 was used for dissolution profile comparison using Herbesser 90 SR as a reference product. Drug release could be sustained in a predictable manner by modifying the content of HPMC or XG. Moreover, the drug release profiles of tablets prepared using these matrix materials were not affected by pH and agitation rate. The f2 values showed that only one batch of tablets (of diltiazem HCl, HPMC or XG, and MCC in proportions of 3.0:3.0:4.0) was considered similar to that of the reference product, with values above 50. The unbiased similarity factor f2* values were not much different from the f2 values, ascribing to a small dissolution variance of the test and reference products. The amount of HPMC or XG incorporated to produce tablets with the desired dissolution profile could be determined from the curves of f2 versus polymer content. Hence, the f2 values can be applied as screening and optimization tools during development of controlled-release preparations.
Lyophilised wafers have been shown to have potential as a modern dressing for mucosal wound healing. The wafer absorbs wound exudates and transforms into a gel, thus providing a moist environment which is essential for wound healing. The objective of this study was to develop a carboxymethyl cellulose wafer containing antimicrobials to promote wound healing and treat wound infection. The pre-formulation studies began with four polymers, sodium carboxymethyl cellulose (NaCMC), methylcellulose (MC), sodium alginate and xanthan gum, but only NaCMC and MC were chosen for further investigation. The wafers were characterised by physical assessments, solvent loss, microscopic examination, swelling and hydration properties, drug content uniformity, drug release and efficacy of antimicrobials. Three of the antimicrobials, neomycin trisulphate salt hydrate, sulphacetamide sodium and silver nitrate, were selected as model drugs. Among the formulations, NaCMC wafer containing neomycin trisulphate exhibited the most desirable wound dressing characteristics (i.e., flexibility, sponginess, uniform wafer texture, high content drug uniformity) with the highest in vitro drug release and the greatest inhibition against both Gram positive and Gram negative bacteria. In conclusion, we successfully developed a NaCMC lyophilised wafer containing antimicrobials, and this formulation has potential for use in mucosal wounds infected with bacteria.
Novel nanoemulsion-based drug delivery systems (DDS) have been proposed as alternative and effective approach for the delivery of various types of poorly water-soluble drugs in the last decade. This nanoformulation strategy significantly improves the cell uptake and bioavailability of numerous hydrophobic drugs by increasing their solubility and dissolution rate, maintaining drug concentration within the therapeutic range by controlling the drug release rate, and reducing systemic side effects by targeting to specific disease site, thus offering a better patient compliance. To date, cavitation technology has emerged to be an energy-efficient and promising technique to generate such nanoscale emulsions encapsulating a variety of highly potent pharmaceutical agents that are water-insoluble. The micro-turbulent implosions of cavitation bubbles tear-off primary giant oily emulsion droplets to nano-scale, spontaneously leading to the formation of highly uniform drug contained nanodroplets. A substantial body of recent literatures in the field of nanoemulsions suggests that cavitation is a facile, cost-reducing yet safer generation tool, remarkably highlighting its industrial commercial viability in the development of designing novel nanocarriers or enhancing the properties of existing pharmaceutical products. In this review, the fundamentals of nanoemulsion and the principles involved in their formation are presented. The underlying mechanisms in the generation of pharmaceutical nanoemulsion under acoustic field as well as the advantages of using cavitation compared to the conventional techniques are also highlighted. This review focuses on recent nanoemulsion-based DDS development and how cavitation through ultrasound and hydrodynamic means is useful to generate the pharmaceutical grade nanoemulsions including the complex double or submicron multiple emulsions.
The pediatric population is an enormously diverse segment of population varying both in size and age. The diversity caused pharmacists face various challenges primarily related to procuring, provision as well as use of drugs in this group of patients. Pediatric dose calculation is particularly a concern for pharmacists. Another challenge faced by pharmacists is unavailability of suitable formulations for pediatric use. This has also led many pharmacists to prepare extemporaneous liquid preparations, even though stability data on such preparations are scarce. Some extemporaneous preparations contain excipients which are potentially harmful in children. Besides that, inadequate labeling and drug information for pediatric drug use had not only challenged pharmacists in recommending and optimizing drug use in children, but also inadvertently caused many drugs used outside the approved terms of the product license (off-label use). Pharmacists are striving to stay connected to overcome the common and comparable challenges faced in their day to day duties and strive to maximize the safe and effective use of medicines for children.
Curcumin (CUR) has been formulated into a host of nano-sized formulations in a bid to improve its in vivo solubility, stability and bioavailability. The aim of this study was to investigate whether the encapsulation of CUR in nanocarriers would impede its biological interactivity, specifically its potential anti-cancer adjuvant activity via the modulation of CYP enzymes in vitro. NanoCUR, a micellar dispersion prepared via a thin film method using only Pluronic F127 as excipient, was amenable to lyophilization, and retained its nano-sized spherical dimensions (17-33 nm) upon reconstitution with water followed by dilution to 5 μM with HBSS or EMEM. NanoCUR was a weaker cytotoxic agent compared to CUR in solution (sCUR), affecting HepG2 cell viability only when the incubation time was prolonged from 4h to 48 h. Correlation with 2h uptake data suggests this was due to a lower cellular uptake rate of CUR from NanoCUR than from sCUR. The poorer CUR accessibility might also account for NanoCUR being a weaker inhibitor of CYP2C9 and CYP2D6 than sCUR. NanoCUR was, however, 1.76-fold more potent against the CYP3A4 (IC50 5.13 ± 0.91 μM) metabolic function. The higher activity against CYP3A4 might be attributed to the synergistic action of Pluronic F127, since the blank micellar dispersion also inhibited CYP3A4 activity. Both sCUR and NanoCUR had no effect on the CYP3A4 mRNA levels in the HepG2 cells. NanoCUR therefore, maintained most of the biological activities of CUR in vitro, albeit at a lower potency and response rate.
The main objective of the present study is the physicochemical characterization of naturally available Terminalia catappa gum (Badam gum [BG]) as a novel pharmaceutical excipient and its suitability in the development of gastroretentive floating drug delivery systems (GRFDDS) to retard the drug for 12 h when the dosage form is exposed to gastrointestinal fluids in the gastric environment. As BG was being explored for the first time for its pharmaceutical application, physicochemical, microbiological, rheological, and stability studies were carried out on this gum. In the present investigation, the physicochemical properties, such as micromeritic, rheological, melting point, moisture content, pH, swelling index, water absorption, and volatile acidity, were evaluated. The gum was characterized by scanning electron microscopy, differential scanning calorimetry (DSC), powder X-ray diffraction studies (PXRD), and Fourier transform infrared spectroscopy (FTIR). Gastroretentive floating tablets of BG were prepared with the model drug propranolol HCl by direct compression methods. The prepared tablets were evaluated for all their physicochemical properties, in vitro buoyancy, in vitro drug release, and rate order kinetics. PBG 04 was selected as an optimized formulation based on its 12-h drug release and good buoyancy characteristics. The optimized formulation was characterized with FTIR, DSC, and PXRD studies, and no interaction between the drug and BG was found. Thus, the study confirmed that BG might be used in the gastroretentive drug delivery system as a release-retarding polymer.
The aim of this study was to develop a taste-masked oral disintegrating film (ODF) containing donepezil, with fast disintegration time and suitable mechanical strength, for the treatment of Alzheimer's disease. Hydroxypropyl methylcellulose, corn starch, polyethylene glycol, lactose monohydrate and crosspovidone served as the hydrophilic polymeric bases of the ODF. The uniformity, in vitro disintegration time, drug release and the folding endurance of the ODF were examined. The in vitro results showed that 80% of donepezil hydrochloride was released within 5 minutes with mean disintegration time of 44 seconds. The result of the film flexibility test showed that the number of folding time to crack the film was 40 times, an indication of sufficient mechanical property for patient use. A single-dose, fasting, four-period, eight-treatment, double-blind study involving 16 healthy adult volunteers was performed to evaluate the in situ disintegration time and palatability of ODF. Five parameters, namely taste, aftertaste, mouthfeel, ease of handling and acceptance were evaluated. The mean in situ disintegration time of ODF was 49 seconds. ODF containing 7 mg of sucralose were more superior than saccharin and aspartame in terms of taste, aftertaste, mouthfeel and acceptance. Furthermore, the ODF was stable for at least 6 months when stored at 40°C and 75% relative humidity.
Orodispersible tablets disintegrate rapidly (within 3 minutes) in the oral cavity and release the medicament before swallowing. The mode of disintegrant addition might affect the properties of orodispersible tablets. The objective of this study was to formulate and evaluate orodispersible tablets by studying different modes of disintegration addition with varying concentrations of disintegrants. The wet granulation method was used to produce the orodispersible tablets. Two methods of disintegration addition were compared (i.e., intragranular, extragranular). Three disintegrants (i.e., cornstarch, sodium starch glycolate, crospovidone) were used at three levels (5%, 10%, and 15%) in the study. The formulations were tested for the powder flowability (angle of repose) and characterized physically (hardness, weight, thickness, friability, disintegration time). The mangosteen pericarp extract was used as a model active pharmaceutical ingredient to be incorporated into the optimum formulation. It was observed that the extragranular method produced granules with better flowability compared to that of the intragranular method. Crospovidone was found as the most efficient disintegrant among the three. The optimum formulation selected was one with the highest concentration of crospovidone (15%), which showed the fastest disintegration time. The mode of disintegrant addition into the orodispersible tablets formulation was found to show a marked difference in the disintegration, as well as other physical characteristics of the orodispersible tablets where the extragranular mode of addition showed better property, which caused the orodispersible tablets to disintegrate the fastest.
Microporous polymeric matrices prepared from poly(ɛ-caprolactone) [PCL] were evaluated for controlled vaginal delivery of the antiprotozoal agent (tinidazole) in the treatment of the sexually transmitted infection, trichomoniasis. The matrices were produced by rapidly cooling co-solutions of PCL and tinidazole in acetone to -80 °C to induce crystallisation and hardening of the polymer. Tinidazole incorporation in the matrices increased from 1.4 to 3.9% (w/w), when the drug concentration in the starting PCL solution was raised from 10 to 20% (w/w), giving rise to drug loading efficiencies up to 20%. Rapid 'burst release' of 30% of the tinidazole content was recorded over 24 h when the PCL matrices were immersed in simulated vaginal fluid. Gradual drug release occurred over the next 6 days resulting in delivery of around 50% of the tinidazole load by day 7 with the released drug retaining antiprotozoal activity at levels almost 50% that of the 'non-formulated' drug in solution form. Basic modelling predicted that the concentration of tinidazole released into vaginal fluid in vivo from a PCL matrix in the form of an intravaginal ring would exceed the minimum inhibitory concentration against Trichomonas vaginalis. These findings recommend further investigation of PCL matrices as intravaginal devices for controlled delivery of antiprotozoal agents in the treatment and prevention of sexually transmitted infections.
Diabetes mellitus is a chronic disease accompanied by a multitude of problems worldwide with subcutaneously administered insulin being the most common therapy currently. Controlledrelease insulin is assumed to be of high importance for long-term glycaemic control by reducing the number of daily injections. Long-acting insulin also mimics the basal insulin levels in normal individuals that may be lacking in diabetic patients. Nanoparticles of carbonate apatite as established for efficient intracellular transport of DNA and siRNA have the potential to be used for sustained release of insulin as responsive nano-carriers. The flexibility in the synthesis of the particles over a wide range of pHs with eventual adjustment of pH-dependent particle dissolution and the manageable variability of particle-integrity by incorporating selective ions into the apatite structure are the promising features that could help in the development of sustained release formulations for insulin. In particular strontium-incorporated carbonate apatite particles were formulated and compared with those of unsubstituted apatite in the context of insulin binding and subsequent release kinetics in DMEM, simulated buffer and finally human blood over a period of 20 hours. Clearly, the former demonstated to have a stronger electrostatic affinity towards the acidic insulin molecules and facilitate to some extent sustained release of insulin by preventing the initial burst effect at physiological pH in comparison with the latter. Thus, our findings suggest that optimization of the carbonate apatite particle composition and structure would serve to design an ideal insulin nano-carrier with a controlled release profile.
N-(Substituted)-5-(1-(4-methoxyphenylsulfonyl)piperidin-4-yl)-4H-1,2,4-triazol-3-ylthio) acetamide were synthesized by following conventional as well as microwave assisted protocol through five consecutive steps under the impact of various reaction conditions to control the reaction time and the yield of product. Starting from 4-methoxybenzenesulfonyl chloride and ethyl isonipecotate, product 3 was obtained which was converted into product 4 by treating with hydrazine hydrate. In step 3, the product 4 was refluxed with methyl isothiocyanate and KOH to yield compound 5 which was finally treated with variety of N-substituted acetamides to yield an array of different new compounds (8a-k). These synthesized compounds were evaluated for their inhibition potential against bovine carbonic anhydrase (bCA-II), acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) enzymes. Compound 8g demonstrated good activity against bCA-II, AChE and BChE with IC50 values of 8.69 ± 0.38 μM, 11.87±0.19 μM and 26.01±0.55 μM respectively. SAR studies assisted with molecular docking were carried out to explore the mode of binding of the compounds against the studied enzymes.