Botulinum toxin A dissolving microneedles for hyperhidrosis treatment: design, formulation and in vivo evaluation.

Multiple periodic injections of botulinum toxin A (BTX-A) are the standard treatment of hyperhidrosis which causes excessive sweating. However, BTX-A injections can create problems, including incorrect and painful injections, the risk of drug entry into the bloodstream, the need for medical expertise, and waste disposal problems. New drug delivery systems can substantially reduce these problems. Transdermal delivery is an effective alternative to conventional BTX-A injections. However, BTX-A's large molecular size and susceptibility to degradation complicate transdermal delivery. Dissolving microneedle patches (DMNPs) encapsulated with BTX-A (BTX-A/DMNPs) are a promising solution that can penetrate the dermis painlessly and provide localized translocation of BTX-A. In this study, using high-precision 3D laser lithography and subsequent molding, DMNPs were prepared based on a combination of biocompatible polyvinylpyrrolidone and hyaluronic acid polymers to deliver BTX-A with ultra-sharp needle tips of 1.5 ± 0.5 µm. Mechanical, morphological and histological assessments of the prepared DMNPs were performed to optimize their physicochemical properties. Furthermore, the BTX-A release and diffusion kinetics across the skin layers were investigated. A COMSOL simulation was conducted to study the diffusion process. The primary stability analysis reported significant stability for three months. Finally, the functionality of the BTX-A/DMNPs for the suppression of sweat glands was confirmed on the hyperhidrosis mouse footpad, which drastically reduced sweat gland activity. The results demonstrate that these engineered DMNPs can be an effective, painless, inexpensive alternative to hypodermic injections when treating hyperhidrosis.

Clinical Safety and Tolerability of A2NTX, a Novel Low-Molecular-Weight Neurotoxin Derived from Botulinum Neurotoxin Subtype A2, in Comparison with Subtype A1 Toxins.

All the botulinum type A neurotoxins available for clinical use are of the A1 subtype. We developed a subtype A2 low-molecular-weight (150 kD (kilo Dalton)) neurotoxin (A2NTX) with less spread and faster entry into the motor nerve terminal than A1 in vitro and in vivo. Preliminary clinical studies showed that its efficacy is superior to A1 toxins. We conducted an open study exploring its safety and tolerability profile in comparison with A1LL (LL type A1 toxin, or onabotulinumtoxinA) and a low-molecular-weight (150 kD) A1 neurotoxin (A1NTX). Those who had been using A1LL (n = 90; 50-360 mouse LD50 units) or A1NTX (n = 30; 50-580 units) were switched to A2NTX (n = 120; 25-600 units) from 2010 to 2018 (number of sessions ~27, cumulative doses ~11,640 units per patient). The adverse events for A2NTX included weakness (n = 1, ascribed to alcoholic polyneuropathy), dysphagia (1), local weakness (4), and spread to other muscles (1), whereas those for A1LL or A1NTX comprised weakness (n = 2, A1NTX), dysphagia (8), ptosis (6), local weakness (7), and spread to other muscles (15). After injections, 89 out of 120 patients preferred A2NTX to A1 for the successive sessions. The present study demonstrated that A2NTX had clinical safety up to the dose of 500 units and was well tolerated compared to A1 toxins.

Recognition of single-stranded nucleic acids by small-molecule splicing modulators.

Risdiplam is the first approved small-molecule splicing modulator for the treatment of spinal muscular atrophy (SMA). Previous studies demonstrated that risdiplam analogues have two separate binding sites in exon 7 of the SMN2 pre-mRNA: (i) the 5'-splice site and (ii) an upstream purine (GA)-rich binding site. Importantly, the sequence of this GA-rich binding site significantly enhanced the potency of risdiplam analogues. In this report, we unambiguously determined that a known risdiplam analogue, SMN-C2, binds to single-stranded GA-rich RNA in a sequence-specific manner. The minimum required binding sequence for SMN-C2 was identified as GAAGGAAGG. We performed all-atom simulations using a robust Gaussian accelerated molecular dynamics (GaMD) method, which captured spontaneous binding of a risdiplam analogue to the target nucleic acids. We uncovered, for the first time, a ligand-binding pocket formed by two sequential GAAG loop-like structures. The simulation findings were highly consistent with experimental data obtained from saturation transfer difference (STD) NMR and structure-affinity-relationship studies of the risdiplam analogues. Together, these studies illuminate us to understand the molecular basis of single-stranded purine-rich RNA recognition by small-molecule splicing modulators with an unprecedented binding mode.

Ammi Visnaga L., a Potential Medicinal Plant: A Review.

Ammi visnaga L. (Visnaga daucoides Gaertn., Family Apiaceae), also known as Khella Baldi or toothpick weed, is an annual or biennial herb indigenous to the Mediterranean region of North Africa, Asia, and Europe. The plant is known to have been used in traditional medicine a long time ago. Nowadays, it is used in modern medicine to treat many aliments such as renal colic and coronary insufficiency, and is used as an antioxidant, antifungal, and antibacterial, with a larvicidal effect on mosquito larvae. Peer-reviewed studies show that these pharmacological activities are due its valuable chemical constituents that include mainly essential oil, polyphenolic compounds including flavonoids, as well as γ-pyrones, represented mainly by khellin and visnagin. Its essential oil is reported to have antiviral, antibacterial, and larvicidal effects, while its flavonoid content is responsible for its antioxidant activity. Its γ-pyrone content has a powerful effect on facilitating the passage of kidney stones and relieving renal colic, in addition to having a relaxant effect on smooth muscle including that of the coronary arteries. The current review represents the progress in research on A. visnaga in terms of either its chemistry or biological activities. This review represents scientific support material for the use of the plant by the pharmaceutical industry.

The Potential Involvement of an ATP-Dependent Potassium Channel-Opening Mechanism in the Smooth Muscle Relaxant Properties of Tamarix dioica Roxb.

Background: Tamarix dioica is traditionally used to manage various disorders related to smooth muscle in the gastrointestinal, respiratory, and cardiovascular systems. This study was planned to establish a pharmacological basis for the uses of Tamarix dioica in certain medical conditions related to the digestive, respiratory, and cardiovascular systems, and to explore the underlying mechanisms. Methods: A phytochemical study was performed by preliminary methods, followed by HPLC-DAD and spectrometric methods. In vivo evaluation of a crude hydromethanolic extract of T.dioica (TdCr) was done with a castor-oil-provoked diarrheal model in rats to determine its antidiarrheal effect. Ex vivo experiments were done by using isolated tissues to determine the effects on smooth and cardiac muscles and explore the possible mechanisms. Results: TdCr tested positive for flavonoids, saponins, phenols, and tannins as methanolic solvable constituents in a preliminary study. The maximum quantity of gallic acid equivalent (GAE), phenolic, and quercetin equivalent (QE) flavonoid content found was 146 ± 0.001 µg GAE/mg extract and 36.17 ± 2.35 µg QE/mg extract. Quantification based on HPLC-DAD (reverse phase) exposed the presence of rutin at the highest concentration, followed by catechin, gallic acid, myricetin, kaempferol, and apigenin in TdCr. In vivo experiments showed the significant antidiarrheal effect of TdCr (100, 200, and 400 mg/kg) in the diarrheal (castor-oil-provoked) model. Ex vivo experiments revealed spasmolytic, bronchodilatory, and vasorelaxant activities as well as partial cardiac depressant activity, which may be potentiated by a potassium channel opener mechanism, similar to that of cromakalim. The potassium channel (KATP channel)-opening activity was further confirmed by repeating the experiments in glibenclamide-pretreated tissues. Conclusions: In vivo and ex vivo studies of T.dioica provided evidence of the antidiarrheal, spasmolytic, bronchodilator, vasorelaxant, and partial cardiodepressant properties facilitated through the opening of the KATP channel.

Two different types of botulinum toxins: Is there a difference in efficacy and longevity?

BACKGROUND: OnabotulinumtoxinA and incobotulinumtoxinA are two botulinum toxin A (BoNT-A) formulations commonly used in esthetic medicine. They are distinguished by whether complexing proteins are included with the active neurotoxin. While OnabotulinumtoxinA has complexing proteins, incobotulinumtoxinA does not; yet, it is unclear whether these differences affect their efficacy, longevity, and immunogenicity, especially in practices with high ambient temperatures. OBJECTIVES: To assess the efficacy and longevity of unreconstituted incobotulinumtoxinA with unreconstituted OnabotulinumtoxinA when stored and transported in a cold box to areas with high external ambient temperatures and to understand the implications of storing and transporting botulinum toxin to tropical areas with high ambient temperatures. METHODS: A prospective, randomized, and evaluator-blinded split-face trial was conducted in 30 patients with symmetrical, moderate-to-severe forehead lines. Following routine transportation and storage in thermocol cold boxes, OnabotulinumtoxinA or incobotulinumtoxinA was injected into corresponding sides of the frontalis to facilitate analysis within the same patient. Using a 4-point facial wrinkling grading scale and a clinical improvement scale, patients' outcomes were assessed over 24 weeks. RESULTS: Forehead lines reappeared in OnabotulinumtoxinA-treated patients after 8.3 weeks, compared to 10.1 weeks in incobotulinumtoxinA-treated patients. While side-vs-side improvements in forehead lines were observed for both toxins, after 8 weeks, improvements from were diminished relative to incobotulinumtoxinA, indicating that incobotulinumtoxinA was more effective at prolonged wrinkle relief. CONCLUSIONS: These results suggest that incobotulinumtoxinA is more stable at higher ambient temperatures, thus contributing to its better efficacy and longevity. IncobotulinumtoxinA is therefore more appropriate for practices in tropical climates.

IncobotulinumtoxinA: A Highly Purified and Precisely Manufactured Botulinum Neurotoxin Type A

Aesthetic dermatologic applications of botulinum neurotoxin (BoNT), including treatment of glabellar lines, horizontal forehead lines, and crow's feet, were the most common non-surgical cosmetic procedures in the US in 2017, with high levels of subject satisfaction. Since the first BoNT type A (BoNT-A) formulation was approved in 1989, the number of formulations available on the world's commercial markets has increased and new approvals are expected. BoNT is produced by Clostridium botulinum in nature as part of a large protein complex. However, the unnecessary clostridial proteins, which dissociate from BoNT under physiological conditions with a half-life of <1 minute, have no role in clinical applications. Data demonstrate that BoNT administration can elicit an immunological response, leading to production of neutralizing antibodies that can be associated with reduced efficacy or treatment non-response. As repeat treatments are required to maintain efficacy, clinicians should be aware of the possibility of antibody development and choose a BoNT with the lowest risk of immunogenicity. IncobotulinumtoxinA is manufactured using advanced technology to precisely isolate the pure BoNT without unnecessary clostridial proteins, and with low immunogenicity and high specific activity. In incobotulinumtoxinA clinical studies, no previously BoNT-naïve subjects developed neutralizing antibodies, and there was no secondary non-response to incobotulinumtoxinA treatment. Here we review the role of unnecessary clostridial proteins in BoNT-A and discuss the unique incobotulinumtoxinA manufacturing and purification process with a focus on the implications for use in aesthetic medicine. J Drugs Dermatol. 2019;18(1):52-57.

Development of a Clinically Relevant Dissolution Method for Metaxalone Immediate Release Formulations Based on an IVIVC Model.

PURPOSE: The aim of the present work was to classify metaxalone according to the Biopharmaceutics Classification System (BCS), to develop a clinically relevant dissolution method that can be used to predict the oral absorption of metaxalone and to establish an in vitro-in vivo correlation (IVIVC). METHODS: Solubility of the drug was studied in different pH media and permeability studies were performed using a Caco-2 cell model. The in vitro dissolution and in vivo disposition of metaxalone from 3 different immediate release (IR) tablet formulations were investigated using USP 2 apparatus and a single dose, four-way, crossover bioequivalence study in healthy humans along with an oral solution of the drug, respectively. An IVIVC was established by using a direct, differential based method. RESULTS: Metaxalone has been confirmed as a Class II drug according to BCS. Bioavailability studies performed in humans demonstrated that dissolution was the rate limiting step for bioavailability of the drug and one of the test products had significantly improved bioavailability compared to the marketed product Skelaxin®. An IVIVC model was developed that demonstrated an acceptable internal predictability. CONCLUSION: The IVIVC demonstrated that formulation factors play a significant role in dissolution and absorption of metaxalone. A pH 4.5 dissolution medium containing 0.5% NaCl with 0.2% SLS (USP apparatus 2 at 50 rpm) is clinically relevant to predict bioavailability of the drug and is superior to the USP method in terms of the Quality by Design (QbD) concept.

Deciphering Structure-Activity Relationships in a Series of 2,2-Dimethylchromans Acting as Inhibitors of Insulin Release and Smooth Muscle Relaxants.

4,6-Disubstituted 2,2-dimethylchromans are reported as pharmacologically active compounds that mainly target the ATP-sensitive potassium channels. The present study is an attempt to characterize the impact of the nature of substituents introduced at the 4- and 6-positions of 2,2-dimethylchromans on their capacities to inhibit insulin release from pancreatic ß-cells or to relax vascular smooth muscle cells, both biological responses that are supposed to reflect interaction with specific ion channels. From the core structure 4-amino-2,2-dimethylchroman, a progressive increase in the steric hindrance of the chemical functionalities introduced at the 4-position (amino, formamido, acetamido, arylureido/thioureido) and at the 6-position (amino, formamido, acetamido, alkoxycarbonylamino) led to a progressive magnification of the inhibitory effect on the insulin release process and, to a lesser extent, of the vasorelaxant activity. Moreover, the dextrorotatory enantiomer of 2,2-dimethylchroman compound 29 was more potent than its levorotatory counterpart for inhibiting the insulin secretory process. Additional pharmacological investigations suggested, however, that the myorelaxant activity of 11 and 15 resulted from a direct Ca2+ entry blockade.

Synthesis and photodegradation studies of analogues of muscle relaxant 1,4-dihydropyridine compounds.

This paper describes the synthesis of 1,4-dihydropyridine compounds (DHPs) endowed with good muscle relaxant activity and stability to light. Six new condensed DHPs were synthesized by the microwave irradiation method. A long-chain ester moiety [2-(methacryloyloxy)ethyl] and various substituents on the phenyl ring were demonstrated to affect the muscle relaxant activity occurring in isolated rabbit gastric fundus smooth muscle strips. Forced photodegradation conditions were applied to the molecules according to the ICH rules. The degradation profile of the drugs was monitored by spectrophotometry coupled with the multivariate curve resolution technique. Formation of the oxidized pyridine derivative was observed for all the studied DHPs, except for one compound, which showed very fast degradation and formation of a second photo-product. Pharmacological tests on the molecules showed a good muscle relaxing effect, with a mechanism similar to that of nifedipine, however, proving to be more stable to light.

Screening and identification of Caulis Sinomenii bioactive ingredients with dual-target NF-κB inhibition and ß2- AR agonizing activities.

Caulis Sinomenii (CS) is a valuable traditional medicine in China. Its extract can act as an anti-inflammatory agent and a vascular smooth muscle relaxant. However, the underlying mechanisms remain unknown. In this study, we developed a simple dual-target method based on ultra-performance liquid chromatography/quadrupole time-of-flight mass spectrometry combined with a dual-target bioactive screening assay for anti-inflammatory and antispasmodic activities to characterize the chemical structure of various bioactive compounds of CS rapidly. Seven potential NF-κB inhibitors were identified, including laudanosoline-1-O-xylopyranose, 6-O-methyl-laudanosoline-1-O-glucopyranoside, menisperine, sinomenine, laurifoline, magnoflorine and norsinoacutin. Furthermore, IL-6 and IL-8 assays confirmed the anti-inflammatory effects of these potential NF-κB inhibitors, in which laudanosoline-1-O-d-xylopyranose and menisperine were revealed as novel NF-κB inhibitors. Among the seven identified alkaloids, three potential ß2 -adrenergic receptor agonists, including sinomenine, magnoflorine and laurifoline, were characterized using a luciferase reporter system to measure for the activity of ß2 -adrenergic receptor agonists. Finally, sinomenine, magnoflorine and laurifoline were identified not only as potential NF-κB inhibitors but also as potential ß2 -adrenegic receptor agonists, which is the first time this has been reported. Molecular dynamic simulation and docking results suggest that the three dual-bioactive constituents could not only inhibit Pseudomonas aeruginosa PAK strain-induced inflammatory responses via a negative regulation of the Braf protein that participates in MAPK signaling pathway but also activate the ß2 -adrenegic receptor. These results suggest that CS extract has dual signaling activities with potential clinical application as a novel drug for asthma.

Reconstituting botulinum toxin drugs: shaking, stirring or what?

Most botulinum toxin (BT) drugs are stored as powders which need to be reconstituted with normal saline before clinical use. As botulinum neurotoxin (BNT), the therapeutically active ingredient, is a large double-stranded protein the process of reconstitution should be performed with special attention to mechanical stress applied. We wanted to test the mechanical stability of BNT during the reconstitution process. For this, 100 MU onabotulinumtoxinA (Botox(®), Irvine, CA, USA) was reconstituted with 2.0 ml of NaCl/H2O. Gentle reconstitution (GR) was performed with a 5 ml syringe, a 0.90 × 70 mm injection needle, one cycle of injection-aspiration-injection and two gentle shakes of the vial. Aggressive reconstitution (AR) was performed with a 5 ml syringe, a 0.40 × 40 mm injection needle, ten injection-aspiration-injection cycles and 30 s of continuous shaking of the vial. AR increased the time to paralysis in the mouse hemidiaphragm assay (HDA) from 72.0 ± 4.6 to 106.0 ± 16.0 min (*p = 0.002, two-tailed t test after Kolmogorov-Smirnova test with Lilliefors correction for normal distribution). Construction of a calibration curve revealed that the increase in the time to paralysis was correlated with a loss of potency of from 100 to 58 MU (-42 %). BT users should use large diameter injection needles for reconstitution, apply two or three injection-aspiration-injection cycles and, maybe, shake the vials a few times to rinse the entire glass wall. Aggressive reconstitution with small diameter needles, prolonged injection-aspiration-injection and violent shaking should be avoided.

Botulinum toxin therapy: reduction of injection site pain by pH normalisation.

Botulinum toxin (BT) is injected intramuscularily and may produce injection site pain (ISP). We wanted to explore whether the pH value of the reconstituted BT drug contributes to ISP and, if so, what strategies can be applied to reduce it. In part 1 of the study, pH values of different reconstitution solutions and of major BT drugs reconstituted with different reconstitution solutions were assessed. In part 2, the effects of reconstitution with normal saline (NS) and Ringer acetate (RA) were compared intraindividually and in a double blind fashion in 34 patients with blepharospasm. pH values of reconstitution solutions were 5.52 ± 0.02 for NS, 6.98 for RA, 6.31 for Ringer lactate, 6.56 for electrolyte and 5.31 for bacteriostatic solution. pH values for NS-reconstitution were 6.09 ± 0.20 for Botox(®), 5.95 ± 0.24 for Dysport(®) and 5.81 ± 0.18 for Xeomin(®). pH values for RA-reconstitution were 6.95 ± 0.03 for Botox(®), 7.01 ± 0.02 for Dysport(®) and 6.87 ± 0.06 for Xeomin(®). By using RA instead of NS the pH could be increased by 0.86 for Botox(®), by 1.06 for Dysport(®) and by 1.06 for Xeomin(®). 47 % of the patients experienced less ISP when Botox(®)-RA was given rather than Botox(®)-NS, 76 % when Xeomin(®)-RA was given rather than Xeomin(®)-NS. None of the patients reported a difference in efficacy between NS- and RA-reconstitution. Despite previous reports, reconstituted BT type A drugs show acidic pH values. Normalising these pH values by use of RA instead of NS reduces ISP considerably without sacrificing clincial efficacy.

Botulinum Toxin Type a as a Therapeutic Agent against Headache and Related Disorders.

Botulinum neurotoxin A (BoNT/A) is a toxin produced by the naturally-occurring Clostridium botulinum that causes botulism. The potential of BoNT/A as a useful medical intervention was discovered by scientists developing a vaccine to protect against botulism. They found that, when injected into a muscle, BoNT/A causes a flaccid paralysis. Following this discovery, BoNT/A has been used for many years in the treatment of conditions of pathological muscle hyperactivity, like dystonias and spasticities. In parallel, the toxin has become a "glamour" drug due to its power to ward off facial wrinkles, particularly frontal, due to the activity of the mimic muscles. After the discovery that the drug also appeared to have a preventive effect on headache, scientists spent many efforts to study the potentially-therapeutic action of BoNT/A against pain. BoNT/A is effective at reducing pain in a number of disease states, including cervical dystonia, neuropathic pain, lower back pain, spasticity, myofascial pain and bladder pain. In 2010, regulatory approval for the treatment of chronic migraine with BoNT/A was given, notwithstanding the fact that the mechanism of action is still not completely elucidated. In the present review, we summarize experimental evidence that may help to clarify the mechanisms of action of BoNT/A in relation to the alleviation of headache pain, with particular emphasis on preclinical studies, both in animals and humans. Moreover, we summarize the latest clinical trials that show evidence on headache conditions that may obtain benefits from therapy with BoNT/A.

Botulinum toxin type B: pH change reduces injection pain, retains efficacy.

BACKGROUND: Injection of botulinum toxin Type B (BTX-B) is substantially more painful than injection of botulinum toxin Type A (BTX-A). OBJECTIVE: A method of reducing pain with BTX-B injection without reducing efficacy. This was evaluated in 2 BTX-A-resistant subjects and another BTX-B-naive subject. METHODS: Clinical evaluation and computer analysis of photographs were used to confirm efficacy to different dilutions of Type B toxin and confirm BTX-A resistance. A pilot study of 3 subjects involves BTX-B (usually pH 5.6) that was diluted with sodium bicarbonate to normalize the pH to 7.5 in the syringe immediately before injection. Pain assessment compared the different pH BTX-B solutions. RESULTS: Two patients with acquired resistance to 3 BTX-As in upper facial muscles responded to BTX-B. Injection pain of BTX-B changed to pH 7.5 was significantly reduced and retained efficacy over 10 weeks. CONCLUSION: Botulinum toxin Type A resistance is documented to 3 BTX-A brands in 2 patients. They had received low doses of Type A toxin, they responded to Type B toxin. Injection pain of the acidic solution of BTX-B neurotoxin was reduced and efficacy not compromised by changing pH of BTX-B solution to pH 7.5. This method improved patient tolerance to BTX-B injections.

Incorrect reconstitution of incobotulinumtoxinA leads to loss of neurotoxin.

BACKGROUND: IncobotulinumtoxinA (INCO) was approved for aesthetic use in the United States in 2011. When reconstituted per manufacturer's instructions, diminished delivery of INCO in US may result. OBJECTIVE: Investigators sought to determine whether potential loss of decreased motor activity could be demonstrated, using a simple reconstitution technique. METHODS AND MATERIALS: In this 5-patient study, investigators added 2.0 mL of saline to INCO powder at the bottom of the first of 5 vials, swirling gently to dissolve INCO powder at the bottom. Reconstituted INCO was discarded and the cap was replaced. The "empty" vial then received 0.6 mL of saline, and was swirled and inverted 3 times to ensure dissolution. The 0.6 mL from the first vial was added to the second "empty" vial and the process was repeated for the remaining 3 vials (5 vials per patient). Patients were injected from reconstitution of "empty" vials to determine neuromodulatory activity. Pre- and post-treatment patient photographs of maximal contraction were taken. RESULTS: Markedly diminished maximal frown could be observed in all 5 patients. CONCLUSION: Improper reconstitution of INCO, or swirling without inversion of the vial following saline injection, can result in significant loss of units of the neurotoxin in the clinical setting.

Chitosan lactate wafer as a platform for the buccal delivery of tizanidine HCl: in vitro and in vivo performance.

Tizanidine HCl is a skeletal muscle relaxant that suffers from extensive hepatic metabolism resulting in 34-40% oral bioavailability. It also suffers from short half-life (2.1-4.2h) that necessitates frequent administration thus reducing patient compliance. In addition, tizanidine HCl is water soluble, so it is a challenging candidate for controlled drug delivery. In our study, tizanidine was encapsulated in chitosan lactate beads cross-linked with sodium tripolyphosphate. The beads were further incorporated into chitosan lactate wafer to be easily applied to buccal mucosa, aiming to bypass the hepatic metabolism. A central composite face-centered design was applied to statistically optimize the formulation variables; tripolyphosphate concentration, chitosan lactate concentration and polymer/drug ratio. The optimized formula suggested by the software composed of; 3.03% tripolyphosphate, 4.92% chitosan lactate and 2.13 polymer/drug ratio. It provided encapsulation efficiency of 56.5% and controlled tizanidine release over 8h. It is also characterized by being mucoadhesive and nonirritant. Pharmacokinetic parameters of tizanidine from the optimized formula were compared to those of the immediate release tablet, Sirdalud(®), as reference in human volunteers using a randomized crossover design. Significant increase was observed for Tmax and AUC(0-∞). The increase in relative bioavailability of TIZ from the optimized formula was 2.27 fold.

Diffusion of two botulinum toxins type A on the forehead: double-blinded, randomized, controlled study.

BACKGROUND: Different diffusion of different botulinum toxin type A (BoNTA) preparations may account for differences in outcomes in cosmetic clinical practice. OBJECTIVES: A double-blind, randomized, self-controlled study was performed to evaluate the diffusion characteristics of onabotulinumtoxinA and a Chinese type A botulinum toxin (CBTX-A). MATERIALS AND METHODS: Healthy volunteers (N = 20) were recruited to receive a 0.05-mL (2 U) injection of BoTNA at four forehead sites (medial forehead (subcutaneous (SC)) and temporal forehead (intradermal (ID))). On day 14, the Minor's iodine starch test was performed and photographs were taken for calculating the area and dimensions of anhydrotic area. RESULTS: When BoNTAs were different, the anhidrosis ID area was significantly greater with CBTX-A than onabotulinumtoxinA, the vertical dimension was significantly longer with CBTX-A ID than onabotulinumtoxinA ID and the horizontal dimension was significantly greater with CBTX-A ID than onabotulinumtoxinA ID. The area of anhidrosis SC was significantly greater with CBTX-A than onabotulinumtoxinA. When injection depths were different, the mean horizontal dimension was significantly greater with onabotulinumtoxinA SC than ID. Comparing the dimension of the same BoNTA and injection method, the vertical dimension was significantly greater than the horizontal dimension. CONCLUSION: OnabotulinumtoxinA diffuses less than CBTX-A. ID injection technique may result in less diffusion than SC.

Mechanisms underlying the relaxant effect of Galetin 3,6- dimethyl ether, from Piptadenia stipulacea (Benth.) Ducke, on guinea-pig trachea.

Galetin 3,6-dimethyl ether (FGAL), a flavonoid from the aerial parts of Piptadenia stipulacea (Benth.) Ducke, was found to exert a relaxant effect on carbachol (CCh)-pre-contracted guinea-pig trachea. Based on cumulative concentration-response curves to CCh, FGAL antagonized muscarinic receptors pseudo-irreversibly and noncompetitively, since it inhibited and shifted these curves towards higher concentrations in a nonparallel manner. In addition, FGAL was more potent in relaxing contractions induced by 18 mM as compared to 60 mM KCl (pD2 = 5:50 ±0:36 and 4.80 ±0.07, respectively), indicating the participation of K+ channels. In the presence of 10 mM tetraethylammonium (TEA+) chloride, a nonselective K+ channel blocker, the relaxant potency of FGAL was reduced (from pD2 = 5:12 ±0:07 to 4.87 ±0.02). Among several selective blockers of K+ channel subtypes, only apamin, an SKCa (small-conductance Ca2+-activated K+ channels) blocker, attenuated the relaxant potency of FGAL (pD2 = 4:85±0:06), suggesting SKCa activation. FGAL was equipotent in relaxing trachea contracted by 60 mM KCl (pD2 =4:80 ±0:07) or 10-6 M CCh (pD2 = 5:02 ±0:07), suggesting CaV (voltage-gated calcium channel), but not ROCs (receptor-operated calcium channels) participation. Furthermore, aminophylline-induced relaxation (pD2 = 4:12 ±0:06) was potentiated around 4-fold (pD2 = 4:80 ±0:44) in the presence of FGAL. Moreover, forskolininduced relaxation (pD2 = 6:51 ±0:06) was potentiated around 2.5-fold (pD2 = 6:90 ±0:05) by FGAL. Conversely, sodium nitroprusside-induced relaxation was unaffected, indicating that the AC/cAMP/PKA pathway, but not the NO pathway, may be modulated by the flavonoid. These results suggest that, in guinea-pig trachea, FGAL induces relaxation by pseudo-irreversible noncompetitive antagonism on muscarinic receptors, modulation of K+ and Ca2+ channels, as well as activation of the AC/cAMP/PKA pathway.

IncobotulinumtoxinA in esthetics.

IncobotulinumtoxinA (Xeomin®/Xeomeen®/Bocouture®/XEOMIN Cosmetic™) is a botulinum toxin type A that differs from other commercially available botulinum toxin type A preparations in that it is free from complexing proteins ([150 kDa]/NT 201). The proven efficacy of incobotulinumtoxinA in various therapeutic indications preceded its use in the field of esthetic medicine, where it is widely approved for the treatment of glabellar frown lines on the basis of positive efficacy and safety findings from a number of clinical trials. Here, we discuss the characteristics of incobotulinumtoxinA and review the clinical data supporting its use in esthetics.