Evaluation of Naringenin as a Promising Treatment Option for COPD Based on Literature Review and Network Pharmacology.

Chronic obstructive pulmonary disease (COPD) is a chronic respiratory disease characterized by incompletely reversible airflow limitation and seriously threatens the health of humans due to its high morbidity and mortality. Naringenin, as a natural flavanone, has shown various potential pharmacological activities against multiple pathological stages of COPD, but available studies are scattered and unsystematic. Thus, we combined literature review with network pharmacology analysis to evaluate the potential therapeutic effects of naringenin on COPD and predict its underlying mechanisms, expecting to provide a promising tactic for clinical treatment of COPD.

Assessment of Pharmacologic Ingredients in Common Over-the-Counter Sinonasal Medications.

Importance: Sinonasal remedies are the most frequently purchased category of over-the-counter (OTC) drugs in the United States. A variety of options for relief are available under proprietary names, although the actual number of available options may not be readily appreciated by the consumer or the clinician. Objective: To determine the prevalence of specific ingredients in OTC sinonasal products. Design, Setting, and Participants: This cross-sectional study took physical inventory of brand-name and generic OTC drugs marketed as sinus, cold, allergy, or nasal remedies. Retail pharmacies in New Orleans, Louisiana, commercial websites, and the Drugs, Herbs and Supplements section of MedlinePlus and drugs.com were searched. Data were collected and analyzed from July 1 to 31, 2018. Main Outcomes and Measures: Frequency of active ingredients in OTC formulations. Results: Five pharmacies were visited to identify 18 brands, for which the commercial websites were then searched. The 14 most common brands represented 211 unique products. Only 8 unique nonanalgesic ingredients were identified among these products, with many products sold under the same brand name and with the same active ingredient. Phenylephrine hydrochloride, dextromethorphan hydrobromide, pseudoephedrine hydrochloride, guaifenesin, chlorpheniramine maleate, brompheniramine maleate, diphenhydramine hydrochloride, and doxylamine succinate were the common active ingredients, with all available OTC sinonasal remedies consisting of 1 or more of these ingredients. The frequency of occurrence of each ingredient ranged from 10 to 261 different products. Combinations of 2, 3, or 4 active ingredients occurred frequently in OTC sinonasal products. Conclusions and Relevance: These findings suggest that proliferation of brand extension products under a common name is pervasive. Clinicians should be aware of the large array of redundant OTC formulations and lack of specificity when discussing brand-name sinonasal remedies with their patients.

Selective quantitation of co-formulated ternary mixture in the presence of potential impurities by liquid chromatographic methods.

Two high performance chromatographic methods were developed and validated for the simultaneous determination of Ambroxol, Guaifenesin and Theophylline in pharmaceutical dosage forms and in the presence of Guaiacol and Caffeine as the officially stated impurities. These were a reversed phase liquid and a thin layer chromatographic methods. The liquid chromatographic separation was achieved using Inertsil ODS-3 C18 column (4.6 mm × 250 mm, 5 µm). Gradient elution was performed using a mixture of solvent A (0.05 M ammonium acetate, pH 3, adjusted with glacial acetic acid) and solvent B (methanol), at a flow rate of 1.0 mL/min. The separated peaks were detected at 260.0 nm. The thin layer chromatography was performed using HPTLC 60 F254 silica gel plates, mobile phase was consisting of ethyl acetate: methanol: acetic acid (10:0.5:1, v/v/v) and detection was performed at 254.0 nm. Validation of the developed methods was achieved according to International Conference on Harmonization (ICH) guidelines. The proposed methods were fast, accurate, precise, and sensitive. Hence, they could be employed for routine quality control of the ternary mixture in capsule and syrup dosage forms.

Development and validation of a generic RP-HPLC PDA method for the simultaneous separation and quantification of active ingredients in cold and cough medicines.

A novel generic reverse phase high performance liquid chromatography (RP-HPLC) method is developed and validated for simultaneous determination of seven pharmaceutically active ingredients, namely, acetaminophen, dextromethorphan, doxylamine, phenylephrine, guaifenesin, caffeine and aspirin. All seven ingredients were quantified in soft gel, syrup and tablet formulations of the over-the-counter US-marketed products, as per the guidelines of the International Conference on Harmonization. The separation was achieved in a 16 min run time on an Agilent Zorbax Phenyl column using a gradient method with two mobile phases. Mobile phase A was 0.15% trifluoro acetic acid in purified water and while mobile phase B was a mixture of acetonitrile and methanol (750:250 v/v) with 0.02% trifluoro acetic acid. The flow rate was 1.0 mL min-1 and injection volume was 10 µL. Detection was performed at 280 nm using a photodiode array detector. As part of the method validation, specificity, linearity, precision and recovery parameters were verified. The concentration and area relationships were linear (R2 > 0.999), over the concentration ranges 20-120 µg mL-1 for acetaminophen, 75-450 µg mL-1 for dextromethorphan, 31.25-187.5 µg mL-1 for doxylamine, 25-150 µg mL-1 for phenylephrine, 25-150 µg mL-1 for aspirin, 6.5-39 µg mL-1 for caffeine and 12-72 µg mL-1 for guaifenesin. The relative standard deviations for precision and intermediate precision were <1.5%. The proposed RP-HPLC generic method is applicable for routine analysis of cold and cough over-the-counter products.

Determination of Passive Dry Powder Inhaler Aerodynamic Particle Size Distribution by Multi-Stage Cascade Impactor: International Pharmaceutical Aerosol Consortium on Regulation & Science (IPAC-RS) Recommendations to Support Both Product Quality Control and Clinical Programs.

The multi-stage cascade impactor (CI) is the mainstay method for the determination of the aerodynamic particle size distribution (APSD) of aerosols emitted from orally inhaled products (OIPs). CIs are designed to operate at a constant flow rate throughout the measurement process. However, it is necessary to mimic an inhalation maneuver to disperse the powder into an aerosol when testing passive dry powder inhalers (DPIs), which constitute a significant portion of available products in this inhaler class. Methods in the pharmacopeial compendia intended for product quality assurance initiate sampling by applying a vacuum to the measurement apparatus using a timer-operated solenoid valve located downstream of the CI, resulting in a period when the flow rate through the impactor rapidly increases from zero towards the target flow rate. This article provides recommendations for achieving consistent APSD measurements, including selection of the CI, pre-separator, and flow control equipment, as well as reviewing considerations that relate to the shape of the flow rate-sampling time profile. Evidence from comparisons of different DPIs delivering the same active pharmaceutical ingredients (APIs) is indicative that the compendial method for APSD measurement is insensitive as a predictor of pharmacokinetic outcomes. Although inappropriate for product quality testing, guidance is therefore provided towards adopting a more clinically realistic methodology, including the use of an anatomically appropriate inlet and mimicking patient inhalation at the DPI while operating the CI at constant flow rate. Many of these recommendations are applicable to the testing of other OIP classes.

Pharmacokinetic study of Sudaxine in dog plasma using novel LC-MS/MS method.

CONTEXT: Sudaxine is a novel respiratory stimulant that increases ventilatory drive via NO+ -thiolate signaling and is under development for reversal of opioid-induced respiratory depression and other critical care indications. OBJECTIVE: This study investigates the pharmacokinetic characteristics after intravenous administration of Sudaxine by using a simple liquid chromatography-tandem mass spectrometry (LC-MS/MS) method. MATERIALS AND METHODS: A sensitive LC-MS/MS method was validated to determine the concentration of Sudaxine in beagle dog plasma after intravenous administration of Sudaxine at (3, 10, 30, and 100 mg/kg). Blood samples (1 mL) were collected at designated time points and SDX concentration was measured for pharmacokinetic study. RESULTS: The calibration curve was linear within the range of 50-5,000 ng/mL with the lower limit of quantification at 50 ng/mL. The CTmax for all doses was reached at 10 minutes (Tmax ). Over the dose range studied, average concentration - time curves and systemic exposure (CTmax and AUC0-t ) increased to Sudaxine dose. The terminal half-life of Sudaxine in dogs ranged from 10 to 30 minutes and about 17.3 ± 1.0% of Sudaxine was protein-bound in dog plasma. DISCUSSION AND CONCLUSIONS: We developed a novel LC-MS/MS method of Sudaxine detection and quantification and determined its pharmacokinetic profiles after intravenous administration in canine subjects. Sudaxine followed first-order kinetics with rapid dose-dependent clearance rates and short half-life making it an ideal candidate for use in a critical care setting with intramuscular or IV administration.

A review on recent technologies for the manufacture of pulmonary drugs.

This review discusses recent developments in the manufacture of inhalable dry powder formulations. Pulmonary drugs have distinct advantages compared with other drug administration routes. However, requirements of drugs properties complicate the manufacture. Control over crystallization to make particles with the desired properties in a single step is often infeasible, which calls for micronization techniques. Although spray drying produces particles in the desired size range, a stable solid state may not be attainable. Supercritical fluids may be used as a solvent or antisolvent, which significantly reduces solvent waste. Future directions include application areas such as biopharmaceuticals for dry powder inhalers and new processing strategies to improve the control over particle formation such as continuous manufacturing with in-line process analytical technologies.

Homemade Hypertonic Saline: Essential Treatment Can Be Available and Affordable.

BACKGROUND: Nebulized hypertonic saline (HS) treatment is unavailable to large populations worldwide. OBJECTIVES: To determine the bacterial contamination and electrolyte concentrations in homemade (HM-HS) vs. pharmacy made (PM-HS). METHODS: We conducted three double-blind consecutive trials: 50 boiled-water homemade 3%-HS (B-HM-HS) bottles and 50 PM-HS. The bottles were cultured after 48 hours. Electrolyte concentrations were measured in 10 bottles (5 per group). Forty bottles (20 per group) were distributed to volunteers for simulation of realistic treatment by drawing 4 ml HS three times daily. From each bottle, 4 ml samples were cultured after 1, 5, and 7 days. Volunteers prepared 108 bottles containing 3%-HS, sterilizing them using a microwave oven (1100-1850W). These bottles were cultured 24 hours, 48 hours, and 1 month after preparation. RESULTS: Contamination rates of B-HM-HS and PM-HS after 48 hours were 56% and 14%, respectively (P = 0.008). Electrolyte concentrations were similar: 3.7% ± 0.4 and 3.5% ± 0.3, respectively (P = NS). Following a single day of simulation B-HM-HS bottles were significantly more contaminated than PM-HS bottles: 75% vs. 20%, respectively (P < 0.01). By day 7, 85% of PM-HS bottles and 100% of B-HM-HS bottles were contaminated (P = 0.23). All 108 microwave-oven prepared bottles (MICRO-HS) were sterile, which was significantly better than the contamination rate of B-HM-HS and PM-HS (P < 0.001). Calculated risk for a consecutive MICRO-HS to be infected was negligible. CONCLUSIONS: Microwave preparation provides sterile HS with adequate electrolyte concentrations, and is a cheap, fast, and widely available method to prepare HS.

Evaluation of Abbreviated Impactor Measurements (AIM) and Efficient Data Analysis (EDA) for Dry Powder Inhalers (DPIs) Against the Full-Resolution Next Generation Impactor (NGI).

The full-resolution next generation impactor (NGI) and three abbreviated impactor systems were used to obtain the apparent aerodynamic particle size distribution (APSD) and other quality measures for marketed dry powder inhalers (DPIs) using the compendial method and efficient data analysis (EDA). APSD for the active pharmaceutical ingredient (API) in Spiriva® Handihaler®, Foradil® Aerolizer®, and Relenza® Diskhaler® was obtained using a full-resolution NGI at 39, 60, and 90 L/min, respectively. Two reduced NGI (rNGI) configurations, the filter-only configuration (rNGI-f) and the modified-cup configuration (rNGI-mc), and the fast-screening impactor (FSI) with appropriate inserts to provide a 5-µm cut size were evaluated. The fine particle dose (FPD) obtained using the FSI for Spiriva was statistically similar to that obtained using the full NGI. However, the FPD for both Foradil and Relenza obtained using the FSI was significantly different from that obtained using the full NGI. Despite this, no significant differences were observed for the fine particle fraction (FPF) obtained using the FSI relative to that obtained from the full NGI for any of the DPIs. The use of abbreviated impactor systems appears promising with good agreement observed with the full-resolution NGI, except for small differences observed for the rNGI-mc configuration. These small differences may be product- and/or flow rate-specific, and further evaluation will be required to resolve these differences.

A Proposed In Vitro Method to Assess Effects of Inhaled Particles on Lung Surfactant Function.

The lung surfactant (LS) lining is a thin liquid film covering the air-liquid interface of the respiratory tract. LS reduces surface tension, enabling lung surface expansion and contraction with minimal work during respiration. Disruption of surface tension is believed to play a key role in severe lung conditions. Inhalation of aerosols that interfere with the LS may induce a toxic response and, as a part of the safety assessment of chemicals and inhaled medicines, it may be relevant to study their impact on LS function. Here, we present a novel in vitro method, based on the constrained drop surfactometer, to study LS functionality after aerosol exposure. The applicability of the method was investigated using three inhaled asthma medicines, micronized lactose, a pharmaceutical excipient used in inhaled medication, and micronized albumin, a known inhibitor of surfactant function. The surfactometer was modified to allow particles mixed in air to flow through the chamber holding the surfactant drop. The deposited dose was measured with a custom-built quartz crystal microbalance. The alterations allowed the study of continuously increasing quantified doses of particles, allowing determination of the dose of particles that affects the LS function. The tested pharmaceuticals did not inhibit the function of a model LS even at extreme doses--neither did lactose. Micronized albumin, however, impaired surfactant function. The method can discriminate between safe inhaled aerosols--as exemplified by the approved inhaled medicines and the pharmaceutical excipient lactose--and albumin known to impair lung functionality by inhibiting LS function.

Developing an in vitro understanding of patient experience with hydrofluoroalkane-metered dose inhalers.

As a result of the Montreal Protocol on Substances that Deplete the Ozone Layer, manufacturers of metered dose inhalers began reformulating their products to use hydrofluoroalkanes (HFAs) as propellants in place of chlorofluorocarbons (CFCs). Although the new products are considered safe and efficacious by the US Food and Drug Administration (FDA), a large number of complaints have been registered via the FDA's Adverse Events Reporting System (FAERS)-more than 7000 as of May 2013. To develop a better understanding of the measurable parameters that may, in part, determine in vitro performance and thus patient compliance, we compared several CFC- and HFA-based products with respect to their aerodynamic performance in response to changes in actuator cleaning interval and interactuation delay interval. Comparison metrics examined in this study were: total drug delivered ex-actuator, fine particle dose (<5 µm), mass median aerodynamic diameter, plume width, plume temperature, plume impaction force, and actuator orifice diameter. Overall, no single metric or test condition distinguishes HFA products from CFC products, but, for individual products tested, there were a combination of metrics that differentiated one from another.

Transport and deposition of pharmaceutical particles in three commercial spacer-MDI combinations.

Respiratory drug delivery has been under the research spotlight for the past few decades, mainly due to the high incidence of pulmonary diseases and the fact that this type of delivery offers the highest efficiency for treatment. Despite its invaluable benefits, there are some major drawbacks to respiratory drug delivery, the most important of which being poor delivery efficiency and relatively high drug deposition in undesirable regions, such as the mouth cavity. One way to improve the efficiency of respiratory drug delivery with metered-dose inhalers is placing a respiratory spacer between the inhaler exit and the mouth. It is argued that high drug deposition in the immediate airways of the respiratory system is strongly affected by relatively high initial momentum of pharmaceutical particles leaving the inhaler. A respiratory spacer, however, can provide an expansion region in which the initial momentum of particles can subside. As a result, particles enter the patient׳s oral cavity more gradually and are more likely to reach the desired regions. In this study, the effectiveness of using three commercial spacers paired with a commercial inhaler is examined through numerical investigation of fluid flow and particle transport phenomena. Particles ranging from 1 to 50 µm in diameter are tracked using a Lagrangian point of view and fluid flow fields are resolved using the LRN k-ω turbulence model. A novel particle injection method is introduced and is demonstrated to be able to adequately capture the effects of particle initial momentum. Lastly, a few design suggestions are made.

The pharmacokinetics of conventional and bioenhanced tablet formulations of danirixin (GSK1325756) following oral administration in healthy, elderly, human volunteers.

Danirixin (GSK1325756) is a small, high-affinity, selective and reversible CXCR2 antagonist in development for treatment of chronic obstructive pulmonary disease. The objective of the study was to evaluate the relative bioavailability, including the inter-subject variability, of a conventional immediate-release (IR) formulation and two prototype bioenhanced formulations of danirixin during gastric acid suppression in a healthy, elderly population. A single-centre, crossover study in healthy male and female volunteers aged 65-80 years was conducted. Subjects were randomised to receive danirixin 50 mg IR in the fed and fasted states and danirixin 50 mg Bioenhanced Formulation 1 and 2 in the fasted state. All subjects also received omeprazole 20 mg each morning beginning 4 days prior to the first treatment period and continuing through danirixin dosing in the final treatment period. Twenty subjects were randomised and completed the study. Bioenhanced Formulation 2 in the fasted state demonstrated the highest adjusted geometric means for AUC(0-t), AUC(0-inf), AUC(0-24) and C max. Danirixin IR demonstrated adjusted means that were higher in the fed state compared with the fasted state. For all formulations tested, there was substantial inter-subject variability (CVb >100 % for all formulations). The overall incidences of adverse events (AEs) were 10 % for danirixin IR (both in the fed and fasted states) and 15-20 % for the bioenhanced formulations. The majority of AEs were mild in intensity. There were no serious AEs. Concomitant use of omeprazole resulted in large inter-subject variability in the exposure to danirixin. Bioenhanced formulation strategies could not overcome the effect of omeprazole on exposure and variability between subjects.

Evaluation of WO-2013040863, WO-2013041042 and WO-2013043962. Selective JAK1 inhibitors based on a 3-aminopyrazole-4-carboxamide scaffold.

1-alkyl-3-arylaminopyrazole-4-carboxamide derivatives have previously been described as JAK2 selective inhibitors. Modification of the 1-substituent to incorporate a 2-cyanoethyl moiety modulates the selectivity for JAK kinases providing JAK1 selective inhibitors. Three patent applications each claim different variations on this scaffold and provide highly potent JAK1 inhibitors, with up to 433-fold selectivity over JAK2. The inhibitors are claimed to be useful in the treatment of respiratory diseases, arthritis and cancer.

Insulin-like growth factor-I aerosol formulations for pulmonary delivery.

Injectable insulin-like growth factor-1 (IGF-I) is therapeutically deployed for severe IGF-I deficiency and clinically explored for various other indications such as muscle wasting disease. In the present study, liquid IGF-I formulations for pulmonal application were screened with regard to buffer type (acetate, citrate, histidine, and succinate), sodium chloride concentration (50-150 mM), and pH value (4.5-6.5). Methionine 59 oxidation (Met(o)) was observed in acetate buffer along with reducible dimer and trimer formation at low pH. Oxidation correlated with formation of covalent, reducible aggregates, and complete loss of potency was observed for severely aggregated samples. Bioactivity was partly retained in cases where complete oxidation but limited aggregation was found. In contrast, IGF-I integrity was preserved in histidine buffer during accelerated stability. After delivery from air-jet or vibrating-mesh nebulizers, limited Met(o) formation and no aggregation was observed. Nebulization performance regarding aerosol output rate, mass median aerodynamic diameter, and fine particle fraction for liquid IGF-I formulation was comparable to 0.9% sodium chloride reference, confirming the suitability for pulmonal application. In conclusion, different IGF-I liquid formulations were studied and compositions were identified maintaining bioactivity and chemical stability throughout storage at accelerated conditions for up to 4 months as well as compatibility with air-jet and vibrating-mesh nebulizers.

Methods for reduction of cohesive forces between carrier and drug in DPI formulation.

Dry powder inhaler (DPI) has become a well accepted drug delivery for pulmonary system to treat many related diseases including symptomatic and life threatening diseases. Successful delivery of dry powder to the lung requires careful consideration of powder production process, formulation and inhaler device. The formulation of DPI mostly comprises of lactose as a carrier for drug delivery. In DPI formulation, particulate interactions within the formulation govern both the drug dissociation from carrier particles and the disaggregation of drug into primary particles with a capacity to penetrate deep into lung. Two contradictory requirements must be fulfilled for this type of dry powder formulation. On one hand, adhesion between carrier and drug must be sufficient for the blend drug/carrier to be stable. On the other hand, adhesion drug/carrier has to be weak enough to enable the release of drug from carrier during patient inhalation. Thus the carrier use restricted due to detachment problem. Different methods are proposed to reduce the cohesive forces between drug and carrier to desired level. Various studies conducted for understanding the mechanism of deposition into lungs and making formulation with optimum carrier drug cohesive force. This review provides information on various processes involved in reducing the cohesive forces between drug and carrier, to a required level.

Measurement of drug in small particles from aqueous nasal sprays by Andersen Cascade Impactor.

PURPOSE: To determine if cascade impactor (CI) measurement of drug in small particles from aqueous nasal sprays, described in FDA's 2003 draft Nasal Bioavailability/Bioequivalence Guidance, can be optimized to reduce measurement variability. To examine the influence of flow rate configurations and number of impactor stages on CI deposition and explore the importance of inlet volume. METHODS: A total of eight assemblies and manual vs. automatic actuation were tested for deposition on the sum of all stages of the CI, and for Group 2 total drug mass per the Guidance. Mean deposition and variance about the mean were determined for each assembly. RESULTS: The path length for a spherical 1 l inlet was too short to allow adequate aerosol formation. Data variance was reduced by a factor of two or more by using an automatic actuator relative to manual actuation. Impactor assembly modification did not improve variance over the standard assembly. CONCLUSIONS: Use of a spherical inlet (≥ 2 l volume) and automatic actuation are recommended for comparative measurements of drug in small particles arising from aqueous nasal sprays. The standard (8-stage) 28.3 lpm CI flow rate configuration is recommended when using the Andersen Cascade Impactor (ACI), as no other assembly showed a distinct advantage.

TRP channels as therapeutic targets in airway disorders: a patent review.

INTRODUCTION: Chronic respiratory diseases, such as asthma and chronic obstructive pulmonary disease, affect millions of patients worldwide. New therapeutic approaches to these conditions are urgently needed since current treatment options provide only symptomatic relief. Transient receptor potential (TRP) ion channels are emerging molecular target candidates for the development of novel, disease-modifying drugs addressing airway diseases. AREAS COVERED: The authors review the patent literature on novel molecules targeting TRP channels (in particular TRPA1, TRPV1, TRPM8 and TRPC6) that are currently studied in clinical trials or are candidates for future clinical evaluation in the management of respiratory diseases. EXPERT OPINION: The patent literature highlights TRPA1 and TRPV1 channels as the most advanced therapeutic targets in respiratory disorders. TRPV1 antagonists relieve cough in preclinical studies. TRPA1 antagonists not only are anti-tussive but also show efficacy in allergic asthma models. However, to date, only minimal clinical data are available regarding the effects of selective, small-molecule TRPV1 and TRPA1 blockers in respiratory disorders. Clearly, long-term clinical studies are required to confirm the expectations based on preclinical data. In conclusion, the current status of this rapidly expanding research area raises cautious optimism for TRPA1 (and possibly also TRPV1) antagonists as promising anti-tussive/anti-asthma drug candidates.

Evaluation of metered dose inhaler spray velocities using phase Doppler anemometry (PDA).

Droplet velocity is an important parameter which can significantly influence inhalation drug delivery performance. Together with the droplet size, this parameter determines the efficiency of the deposition of MDI products at different sites within the lungs. In this study, phase Doppler anemometry (PDA) was used to investigate the instantaneous droplet velocity emitted from MDIs as well as the corresponding droplet size distribution. The nine commercial MDI products surveyed showed significantly different droplet velocities, indicating that droplet velocity could be used as a discriminating parameter for in vitro testing of MDI products. The droplet velocity for all tested MDI products decreased when the testing distance was increased from 3 cm to 6 cm from the front of mouthpiece, with CFC formulations showing a larger decrease than HFA formulations. The mean droplet diameters of the nine MDIs were also significantly different from one-another. Droplet size measurements made using PDA (a number-based technique) could not be directly compared to results obtained using laser light scattering measurements (a volume-based technique). This work demonstrates that PDA can provide unique information useful for characterizing MDI aerosol plumes and evaluating MDI drug delivery efficiency. PDA could also aid the evaluation of in vitro equivalence in support of formulation or manufacturing changes and in evaluation of abbreviated new drug applications (ANDAs) for MDIs.

In vitro alterations in dental enamel exposed to acidic medicines.

OBJECTIVE: To evaluate the effect of acidic medicines (Klaricid(®), Claritin(®), and Dimetapp(®)) on surface enamel in vitro. METHODS: Enamel blocks (n=104) were randomly distributed into two groups: G1 (pH-cycling simulating physiological oral conditions) and G2 (erosive conditions). Each group was divided into four subgroups, three to be immersed in the medicines and the control in deionized water. Specimen surfaces were evaluated for roughness and hardness at baseline and again after the in vitro experimental phase, which included 30 min immersions in the medicines twice daily for 12 days. Scanning electron microscopy (SEM) was also performed after the in vitro experimental phase. RESULTS: All medicines produced a significant reduction in hardness in G1 after 12 days (P<0.05). The three medicines promoted greater roughness after both pH-regimens - G1 and G2 (P<0.01), except for Claritin in G1. Scanning electron microscopy analysis showed erosive patterns in all subgroups. Dimetapp(®) showed the most erosion and Klaricid(®) the least, in both groups. CONCLUSION: Dimetapp(®) (lowest pH and viscosity) and deionized water (control) showed the most pronounced erosive patterns. Klaricid(®) (highest pH and viscosity) presented an in vitro protective effect against acid attacks perhaps due to its mineral content and viscosity.