Formulation of an antispasmodic drug as a topical local anesthetic

Novel ultra-stretchable and self-healing crosslinked poly (ethylene oxide)-cationic guar gum hydrogel

Hydrogels are three-dimensional structures with specific features that render them useful for biomedical applications, such as tissue engineering scaffolds, drug delivery systems, and wound dressings. In recent years, there has been a significant increase in the search for improved mechanical properties of hydrogels derived from natural products to extend their applications in various fields, and there are different methods to obtain strengthened hydrogels. Cationic guar gum has physicochemical properties that allow it to interact with other polymers and generate hydrogels. This study aimed to develop an ultra-stretchable and self-healing hydrogel, evaluating the influence of adding PolyOX [poly(ethylene oxide)] on the mechanical properties and the interaction with cationic guar gum for potential tissue engineering applications. We found that variations in PolyOX concentrations and pH changes influenced the mechanical properties of cationic guar gum hydrogels. After optimization experiments, we obtained a novel hydrogel, which was semi-crystalline, highly stretchable, and with an extensibility area of approximately 400 cm2, representing a 33-fold increase compared to the hydrogel before being extended. Moreover, the hydrogel presented a recovery of 96.8% after the self-healing process and a viscosity of 153,347 ± 4,662 cP. Therefore, this novel hydrogel exhibited optimal mechanical and chemical properties and could be suitable for a broad range of applications in different fields, such as tissue engineering, drug delivery, or food storage.

The biliary continuum: an up-to-date look at biliary tract diseases

In  the  structure of  gastrointestinal diseases, the  pathology of  the  hepatobiliary system currently ranks second in  frequency of occurrence. The stages of diseases of the biliary system can be combined into the so-called “biliary continuum”, when one patient has a consistent development of pathogenetically related diseases of the biliary tract. The progressive course of functional motility disorders of the biliary tract gradually leads to the development of organic pathology, including chronic cholecystitis, the subsequent development of gallstone disease and possible postcholecystectomy complications. Among the diseases of the biliary system, one of the most frequently used diagnoses is chronic cholecystitis. The development of chronic cholecystitis is associated with repeated attacks of acute inflammation or prolonged irritation of large gallstones. The clinical aspects of chronic cholecystitis and other pathologies included in the the «biliary continuum» largely depends on concomitant dyskinesia. There are several directions for the treatment of pathologies of the biliary system: diet therapy, medication, endoscopic and surgical treatment. According to the latest guidelines, the most important direction in modern therapy of diseases of the biliary system is the restoration of the motility of the biliary tract and the normalization of the physicochemical properties of bile. The central place in the treatment of diseases of the “biliary continuum” is given to antispasmodic drugs. The administration of antispasmodics is recommended in order to relieve biliary pain and dyspeptic symptoms caused by spasm of smooth muscles, as well as to control the inflammatory process due to a decrease in the release of pro-inflammatory substances. This article describes in detail the importance of the recovery of the biliary tract motor activity and the improvement of the physico-chemical properties of bile acids.

Polymer-Based Carriers in Dental Local Healing-Review and Future Challenges

Polymers in drug formulation technology and the engineering of biomaterials for the treatment of oral diseases constitute a group of excipients that often possess additional properties in addition to their primary function, i.e., biological activity, sensitivity to stimuli, mucoadhesive properties, improved penetration of the active pharmaceutical ingredient (API) across biological barriers, and effects on wound healing or gingival and bone tissue regeneration. Through the use of multifunctional polymers, it has become possible to design carriers and materials tailored to the specific conditions and site of application, to deliver the active substance directly to the affected tissue, including intra-periodontal pocket delivery, and to release the active substance in a timed manner, allowing for the improvement of the form of application and further development of therapeutic strategies. The scope of this review is polymeric drug carriers and materials developed from selected multifunctional groups of natural, semi-synthetic, and synthetic polymers for topical therapeutic applications. Moreover, the characteristics of the topical application and the needs for the properties of carriers for topical administration of an active substance in the treatment of oral diseases are presented to more understand the difficulties associated with the design of optimal active substance carriers and materials for the treatment of lesions located in the oral cavity.

Nanotechnology application to local anaesthesia (LA)

Several advancements have been made on the exact release of local anaesthetics formulation and its efficiency at inducing motor and sensory block for an extended time has been harnessed in clinical practice. The use of sustained release formulations delivers analgesia for a lengthier period of time with one administration, thereby reducing complications that usually arise with administration of conventional analgesia. In addition, controlled release of an anaesthetic drug is said to prevent overdosing, reduced side effects, especially cardiotoxicity, neurotoxicity and tissue lesions. The use of nanotechnology knowledge via liposomal formulation has recorded high successful results in pain control and quick patient recovery.

A Mathematical Model on the Resolution of Extrusion Bioprinting for the Development of New Bioinks

Pneumatic extrusion-based bioprinting is a recent and interesting technology that is very useful for biomedical applications. However, many process parameters in the bioprinter need to be fully understood in order to print at an adequate resolution. In this paper, a simple yet accurate mathematical model to predict the printed width of a continuous hydrogel line is proposed, in which the resolution is expressed as a function of nozzle size, pressure, and printing speed. A thermo-responsive hydrogel, pluronic F127, is used to validate the model predictions. This model could provide a platform for future correlation studies on pneumatic extrusion-based bioprinting as well as for developing new bioink formulations.

Mucoadhesive in situ gel formulation for vaginal delivery of clotrimazole: formulation, preparation, and in vitro/in vivo evaluation

The purpose of this study was to develop a suitable mucoadhesive in situ gel formulation of clotrimazole (CLO) for the treatment of vaginal candidiasis. For this aim, the mixture of poloxamer (PLX) 407 and 188 were used to prepare in situ gels. Hydroxypropyl methylcellulose (HPMC) K100M or E50 was added to in situ gels in 0.5% ratio to improve the mucoadhesive and mechanical properties of formulations and to prolong the residence time in vaginal cavity. After the preparation of mucoadhesive in situ gels; gelation temperature/time, viscosity, mechanical, mucoadhesive, syringeability, spreadibility and rheological properties, in vitro release behavior, and anticandidal activities were determined. Moreover vaginal retention of mucoadhesive in situ gels was investigated with in vivo distribution studies in rats. Based on the obtained results, it was found that gels prepared with 20% PLX 407, 10% PLX 188 and 0.5% HPMC K100M/E50 might be suitable for vaginal administration of CLO. In addition, the results of in vivo distribution studies showed that gel formulations remained on the vaginal mucosa even 24 h after application. In conclusion, the mucoadhesive in situ gels of CLO would be alternative candidate for treatment of vaginal candidiasis since it has suitable gel properties with good vaginal retention.

Pharmacokinetic Profile and Acute Toxicological Properties of a Novel Radiosensitizer Cytosine-Phosphate-Guanosine Oligodeoxynucleotide 107 in Mice Following Intravenous and Orthotopic Administration

The synthetic cytosine-phosphate-guanosine oligodeoxynucleotide 107 (CpG ODN107) is a novel radiosensitizer for glioma treatment. However, the information related to its pharmacokinetics and toxicity remains unclear. Therefore, the plasma pharmacokinetics, distribution, elimination, and acute toxicity of CpG ODN107 in mice were investigated in the present experiments. The results from the liquid chromatography-tandem mass spectrometry (LC-MS/MS) assay showed that the plasma elimination half-life (t1/2β) of CpG ODN107 in BALB/c mice varied slightly with the dose, and it was 0.65, 0.49, and 0.50 h at the intravenous doses of 2.5, 5, and 10 mg/kg, respectively. CpG ODN107 rapidly and widely distributed in organs/tissues, except the brain and testes. The highest concentrations were found in the liver (28.6% of the administered dose after 0.5 h) and the kidneys (5.7% of the administered dose after 1 h). CpG ODN107 (0.3, 3, and 30 μg/mL) could highly bind to human and mouse plasma proteins in vitro. CpG ODN107 in the forms of prototype was excreted in urine (1.79%) and feces (0.91%), and its shortened metabolites were excreted in urine (2.1%) and feces (2.2%) within the first 24 h. The mice in vivo optical image showed CpG ODN107 labeled with Alexa Fluor 680 fluorochrome (AF680) accumulated in the brain after orthotopic injection, eliminated very slowly, and excreted in urine compared with poly T labeled with AF680. The median lethal dose (LD50) of CpG ODN107 was 75.7 mg/kg for mice; this dose only could produce apparent spleen and liver damage, in line with the distribution features of CpG ODN. In conclusion, our present pharmacokinetic and toxicity investigation will provide helpful information to further pharmacodynamic and pharmacokinetic research of CpG ODN107 and other oligodeoxynucleotide drugs in the future.

Thermosensitive periodontal sol of ciprofloxacin hydrochloride and serratiopeptidase: Pharmaceutical and mechanical analysis

AIM

The aim of the present work was to explore the development of a dual-controlled release periodontal system of a potent broad spectrum first-generation fluoroquinolone, ciprofloxacin, and the anti-inflammatory enzyme serratiopeptidase (STP).

MATERIALS AND METHODS

Based on 3(2) full factorial design, thermoreversible periodontal sols capable of controlled dual delivery of ciprofloxacin hydrochloride and STP were designed using pluronic F127 and carbopol 934P as thermosensitive gelling polymers. Sol gel transition characteristics, %cumulative drug release at 48(th) h and exvivo mucoadhesive strength were designated as dependent responses. The sols were mucoadhesive, syringeable, and inverted into gels at simulated periodontal cavity temperature.

RESULTS

F9 with optimal drug release was identified as the best formulation. Extra design check point generated using Design Expert software 8.02 (Stat-Ease, USA) validated the experimental design. Textural analysis revealed that the developed sols were syringeable and spreadable enough for periodontal treatment so it can be expected that hardness and compressibility of sols would pose no problem during clinical application. The in vitro release behavior exhibited controlled release of both cipro HCl and STP (>90% release).

CONCLUSION

A dual-controlled release thermoreversible periodontal sol of ciproflaxin and STP was successfully developed. Incorporation of STP as anti-inflammatory agent has the potential of developing a therapeutically efficacious system of cipro HCl for treatment of periodontal inflammatory anaerobic infections.

In-situ gel formulations of econazole nitrate: preparation and in-vitro and in-vivo evaluation

OBJECTIVES

This study describes the in-situ gelling of econazole nitrate containing thermosensitive polymers composed of poloxamer 407 and 188 as a novel treatment platform for vaginal candidiasis.

METHODS

Aqueous thermosensitive formulations containing 1% of econazole nitrate and poloxamer 407 and/or 188 were prepared and their rheological, mechanical and drug-release properties determined at 20 ± 0.1°C and/or 37 ± 0.1°C. Based on their biologically suitable thermorheological properties, formulations containing the mixtures of poloxamer 407 and 188 in ratios of 15:15 (F1), 15:20 (F2) and 20:10 (F3) were chosen for comprehensive analysis.

KEY FINDINGS

Formulations based on F3 exhibited typical gel-type mechanical spectra (G' > G″) at 37°C whereas formulations based on F1 and F2 exhibited properties akin to weakly cross-linked gels. Texture profile analysis demonstrated that F3 showed the highest cohesiveness, adhesiveness, hardness and compressibility. No statistically significant differences (P > 0.5) were observed in the release of econazole nitrate from the formulations at pH 4.5, which in all cases followed anomalous diffusion kinetics. Formulations based on 20% poloxamer 407:10% poloxamer 188 were chosen for in-vivo studies and were shown to be effective for the treatment of the vaginal candidiasis. Histopathologic evaluation also supported the effectiveness of the thermosensitive formulation administered intravaginally.

CONCLUSION

By careful engineering of the rheological properties, in-situ thermosensitive gel formulations of econazole nitrate were prepared and were shown to be efficacious in the treatment of vaginal candidiasis.

Statistical optimization of insulin-loaded Pluronic F-127 gels for buccal delivery of basal insulin

The principle of statistical optimization was employed to fabricate insulin-loaded Pluronic F-127 (PF-127) gel formulations having the potential for buccal delivery of basal insulin. A two-level resolution III fractional factorial design was applied to simultaneously evaluate five independent formulation variables: PF-127 concentration, insulin concentration, sodium sulfate concentration, hydroxypropylmethyl cellulose (HPMC) concentration, and presence of sodium glycocholate. The amount of insulin released and permeated from gels as well as gelation time and mucoadhesion force of gels were measured and used as dependent response variables for formulation optimization. Optimization of a gel formulation was achieved by applying constrained optimization via regression analysis. In vitro permeation flux of insulin from the optimized formulation through procine buccal mucosa was 93.17 (±0.058, n = 3) μg/cm(2). Plasma insulin levels following buccal administration of the optimized formulation at 10, 25 and 50 IU/kg to healthy rats were found to be dose dependent and basal insulin levels were maintained at least for 8 h. Furthermore, continuous hypoglycemia for at least 8 h was observed with 89%, 51% and 25% of blood glucose reduction, respectively, for these three doses. The results of this investigation conclude the feasibility of development of optimized buccal insulin-loaded Pluronic F-127 gels for basal insulin delivery.

Design and formulation of mebeverine HCl semisolid formulations for intraorally administration

Gel formulations of mebeverine hydrochloride (MbHCl) containing hydroxypropylmethylcellulose (HPMC), metolose (MTL), and poloxamer 407 (PLX) were prepared to be used in the treatment of different oral painful conditions. HPMC was used as a mucoadhesive gel base while MTL and PLX were used to prepare sol-gel thermosensitive gels. MTL and PLX formulations showed proper sol-gel transition temperature for intraoral application. Formulations were evaluated in terms of their viscosity, mechanical properties, mucoadhesivity, stability, and in vitro drug release. The formulation prepared with 2% of HPMC K100M provided the highest viscosity at room temperature. However, the viscosity of HPMC-PLX mixture showed a significant increase at body temperature. The greatest mucoadhesion was also noted in HPMC-PLX combinations. Texture profile analysis exhibited the differences of the adhesion, hardness, elasticity, cohesiveness, and compressibility of the formulations. The release profiles of MbHCl were obtained, and non-Fickian release was observed from all the formulations. The formulations were stored at different temperature and relative humidity. No significant changes were observed at the end of the 3 months. HPMC-PLX formulation of MbHCl was chosen for in vivo studies, and it remained longer than dye solution on the rabbit's intraoral mucosal tissue. It was found worthy of further clinical evaluation.

Carboxymethyl mungbean starch as a new pharmaceutical gelling agent for topical preparation

An application of carboxymethyl mungbean starch (CMMS) as a gelling agent in the topical pharmaceutical preparation was investigated. CMMS was prepared using specific conditions that yielded a high-viscosity product. Polymer gels and gel bases were prepared at 1-10% (wt/wt), and physicochemical studies were carried out in comparison with four standard gelling agents: carbopol 940 (CP), hydroxypropylmethyl cellulose (HPMC), methyl cellulose (MC), and sodium carboxymethyl cellulose (SCMC). Piroxicam was used as a model drug to study the drug release profile of the gel formulations. The tackless, greaseless, and transparent CMMS gels exhibited pseudoplastic behavior with thixotropy at concentrations less than 5% (wt/wt). At a concentration of 5% (wt/wt) and higher, the semisolid gels showed plastic flow characteristics. Viscosity and X-ray diffraction results indicated a good compatibility between CMMS and the acidic piroxicam. No precipitation of piroxicam or phase separation was observed during a stability test. The release rate of piroxicam from 3% (wt/wt) CMMS gel was 1,003.79 +/- 105.08 microg/cm(2), which was comparable with 947.66 +/- 133.70 microg/cm(2) obtained from a 0.5% (wt/wt) carbopol formulation. The release profiles of both formulations were consistent and remained unchanged after 2 months' storage. Viscosity played an important role in controlling the release rate of low concentration CMMS formulations by regulating the drug diffusion. At a concentration of 5% (wt/wt) CMMS and higher, the release rates of piroxicam were not significantly different. A plausible explanation based on the nature of the gelling agent was proposed. Stability and drug release profiles of CMMS and commercial gelling agents were compared. The results supported the potential use of CMMS as a new, effective gelling agent for topical gel preparation.

Formulation and evaluation of PLA and PLGA in situ implants containing secnidazole and/or doxycycline for treatment of periodontitis

The purpose of this study is to formulate in situ implants containing doxycycline hydrochloride and/or secnidazole that could be used in the treatment of periodontitis by direct periodontal intrapocket administration. Biodegradable polymers [poly (lactide) (PLA) and poly (lactide-co-glycolide) (PLGA)], each polymer in two concentrations 25%w/w, 35%w/w were used to formulate the in situ implants. The rheological behavior, in vitro drug release and the antimicrobial activity of the prepared implants were evaluated. Increasing the concentration of each polymer increases the viscosity and decreases the percent of the drugs released after 24 h. PLA implants showed a slower drugs release rate than PLGA implants in which the implants composed of 25% PLGA showed the fastest drugs release. The in vitro drug release and antimicrobial activity results were compared with results of Atridox. Results revealed that the pharmaceutical formulation based on 25% PLGA containing secnidazole and doxycycline hydrochloride has promising activity in treating periodontitis in comparison with Atridox.

Effect of flavors on the viscosity and gelling point of aqueous poloxamer solution

This study examined the effects of flavors, which are usually added to improve the appeal of pharmaceutical agents, on the viscosity and gelling point of 18% (w/w) aqueous poloxamer 407 solutions. Monoterpenes, esters, alcohols, aldehyde . ketones and lactone type flavors were examined. The concentrations of flavor ranged from 0.1 to 1.0% (w/w). After adding a flavor to the aqueous poloxamer 407 solution, the viscosity of the solution was measured using a Brookfield viscometer, and the gelling point was determined from the viscosity vs. temperature plot. The gelling point of the aqueous poloxamer 407 solution decreased with increasing concentration of flavors except for coumarin, vanillin and ethylvanillin. Thermal analysis with DSC showed an interaction between the flavors and poloxamer 407. These results suggest that the flavors bind to the hydrophilic end chains of poloxamer 407, which increases the viscosity, causing gelation at lower temperatures.