Investigation on improvement of enantioseparation based on clindamycin phosphate by chiral deep eutectic solvents in capillary electrophoresis.

In this work, the potential synergetic effect between deep eutectic solvents and an antibiotic chiral selector (clindamycin phosphate) for enantioseparation was investigated in capillary electrophoresis. We synthesized a series of deep eutectic solvents with choline chloride as hydrogen bond acceptor and three α-hydroxyl acids (l-lactic acid, l-malic acid, and l-tartaric acid) as hydrogen bond donors. Compared to the single clindamycin phosphate separation system, significantly improved separations of model drugs were observed in several synergetic systems. Compared to deep eutectic solvents with a single hydrogen bond donor, deep eutectic solvents with mixed-type hydrogen bond donors were superior. The influences of several key parameters including the type and proportion of organic modifier, clindamycin phosphate concentrations, deep eutectic solvents concentrations, and buffer pH were investigated in detail. The mechanism of the enhanced separations in deep eutectic solvents systems was investigated by means of electroosmotic flow analysis, nuclear magnetic resonance analysis, and molecular modeling. It was the first time that the synergetic systems between deep eutectic solvents and antibiotic chiral selector were established in capillary electrophoresis, and these deep eutectic solvents were demonstrated to have a good synergetic effect with clindamycin phosphate for enantioseparation.

Clindamycin Phosphate 1.2%/Adapalene 0.15%/Benzoyl Peroxide 3.1% Gel for Male and Female Acne: Phase 3 Analysis.

BACKGROUND: Clindamycin phosphate 1.2%/adapalene 0.15%/benzoyl peroxide 3.1% gel (CAB) is the only fixed-dose triple-combination treatment approved for acne. This post hoc analysis assessed the impact of sex on efficacy and safety/tolerability of CAB. METHODS: In two multicenter, double-blind, phase 3 studies (NCT04214639 and NCT04214652), participants aged ≥9 years with moderate-to-severe acne were randomized (2:1) to 12 weeks of once-daily treatment with CAB or vehicle gel. Pooled data were analyzed by sex. Assessments included treatment success (≥2-grade reduction from baseline in Evaluator’s Global Severity Score and a score of 0 [clear] or 1 [almost clear]), inflammatory/noninflammatory lesion counts, Acne-Specific Quality of Life (Acne-QoL) questionnaire, treatment-emergent adverse events (TEAEs), and cutaneous safety/tolerability. RESULTS: At week 12, treatment success rates were significantly greater with CAB versus vehicle irrespective of sex (females: 53.7% vs 23.0%; males: 43.1% vs 24.6%; P<0.05, both). CAB-treated female and male participants both experienced greater reductions from baseline versus vehicle in inflammatory (females: 77.7% vs 57.9%; males: 77.5% vs 57.1%; P<0.001, both) and noninflammatory lesions (females: 72.5% vs 45.6%; males: 72.3% vs 49.6%; P<0.001, both). Acne-QoL improvements from baseline to week 12 were significantly greater with CAB than vehicle. No significant differences in any efficacy measures between CAB-treated males and females were observed. Most TEAEs were of mild-to-moderate severity; no sex-based trends for safety/tolerability were observed. CONCLUSIONS: CAB demonstrated comparable efficacy, quality-of-life improvements, and safety in female and male participants with moderate-to-severe acne. As the first fixed-dose, triple-combination topical formulation, CAB represents an important new treatment for acne. J Drugs Dermatol. 2024;23(10):873-881. doi:10.36849/JDD.8484.

Triple-Combination Clindamycin Phosphate 1.2%/Adapalene 0.15%/Benzoyl Peroxide 3.1% Gel for Acne in Adult and Pediatric Participants.

BACKGROUND: Topical clindamycin phosphate 1.2%/adapalene 0.15%/benzoyl peroxide 3.1% gel (CAB) is the first fixed-dose triple-combination approved for the treatment of acne. This post hoc analysis investigated the efficacy and safety of CAB in pediatric (<18 years) and adult (greater than or equal to 18 years) participants. METHODS: In two multicenter, double-blind, phase 3 studies (NCT04214639 and NCT04214652), participants greater than or equal to 9 years of age with moderate-to-severe acne were randomized (2:1) to 12 weeks of once-daily treatment with CAB or vehicle gel. Pooled data were analyzed for pediatric and adult subpopulations. Assessments included treatment success (greater than or equal to 2-grade reduction from baseline in Evaluator's Global Severity Score and a score of 0 [clear] or 1 [almost clear], inflammatory/noninflammatory lesion counts, Acne-Specific Quality of Life (Acne-QoL) questionnaire, treatment-emergent adverse events (TEAEs), and cutaneous safety/tolerability. RESULTS: At week 12, treatment success rates for both pediatric and adult participants were significantly greater with CAB (52.7%; 45.9%) than with vehicle (24.0%; 23.5%; P<0.01, both). CAB-treated participants in both subgroups experienced greater reductions from baseline versus vehicle in inflammatory (pediatric: 78.6% vs 50.4%; adult: 76.6% vs 62.8%; P<0.001, both) and noninflammatory lesions (pediatric: 73.8% vs 41.1%; adult: 70.7% vs 52.2%; P<0.001, both). Acne-QoL improvements from baseline to week 12 were significantly greater with CAB than with a vehicle. Most TEAEs were of mild-to-moderate severity; no age-related trends for safety/tolerability were observed.  Conclusions: CAB gel demonstrated comparable efficacy, quality of life improvements, and safety in pediatric and adult participants with moderate-to-severe acne. As the first fixed-dose, triple-combination topical formulation, CAB represents an important new treatment option for patients with acne. J Drugs Dermatol. 2024;23(6):394-402.     doi:10.36849/JDD.8357.

Injectable Platelet-Rich Fibrin as a Drug Carrier Increases the Antibacterial Susceptibility of Antibiotic-Clindamycin Phosphate.

The aim of this study was to investigate the change in clindamycin phosphate antibacterial properties against Gram-positive bacteria using the platelet-rich fibrin as a carrier matrix, and evaluate the changes in the antibiotic within the matrix. The antibacterial properties of CLP and its combination with PRF were tested in a microdilution test against reference cultures and clinical isolates of Staphylococcus aureus (S. aureus) or Staphylococcus epidermidis (S. epidermidis). Fourier-transform infrared spectroscopy (FTIR) and scanning electron microscope (SEM) analysis was done to evaluate the changes in the PRF_CLP matrix. Release kinetics of CLP was defined with ultra-performance liquid chromatography (UPLC). According to FTIR data, the use of PRF as a carrier for CLP ensured the structural changes in the CLP toward a more active form of clindamycin. A significant decrease in minimal bactericidal concentration values (from 1000 µg/mL to 62 µg/mL) against reference cultures and clinical isolates of S. aureus and S. epidermidis was observed for the CLP and PRF samples if compared to pure CLP solution. In vitro cell viability tests showed that PRF and PRF with CLP have higher cell viability than 70% after 24 h and 48 h time points. This article indicates that CLP in combination with PRF showed higher antibacterial activity against S. aureus and S. epidermidis compared to pure CLP solution. This modified PRF could be used as a novel method to increase drug delivery and efficacy, and to reduce the risk of postoperative infection.

Population physiologically based modeling of pirlimycin milk concentrations in dairy cows.

Predictions of drug residues in milk are critical in food protection and are a major consideration in the economics of treatment of mastitis in dairy cows. Nonlinear mixed-effects modeling (NLME) has been advocated as a suitable pharmaco-statistical method for the study of drug residues in milk. Recent developments in physiologically based pharmacokinetic (PBPK) modeling of intramammary drugs allow the combination of a mechanistic description of milk pharmacokinetics with NLME methods. The PBPK model was applied to NLME analysis of a data set consisting of milk drug concentrations from 78 healthy cows and 117 with clinical mastitis. Pirlimycin milk pharmacokinetics were adequately described by the model across the range of observed concentrations. Mastitis was characterized by increased variance in milk production volume. Udder residual volume was larger in cows with 1, or 2 or greater diseased mammary glands than in the healthy cows. Low-producing cows had a greater risk of prolonged milk residues. With the exclusion of the low-production cows, the model predicted that healthy cows required a milk discard time 12 h longer than that indicated by the label, and the diseased cows 36 h longer than indicated by the label. More pirlimycin was systemically absorbed in the gram-positive infected compared with the gram-negative infected or healthy cows, suggesting a greater risk of violative meat residues in gram-positive infected cows. Using NLME and PBPK models, we identified factors associated with changes in pirlimycin milk residues that may affect food safety. This model extends the verification of a simple physiologically based framework for the study of intramammary drugs.

The effect of intramammary pirlimycin hydrochloride on the fecal microbiome of early-lactation heifers.

The purpose of this study was to determine the effect of intramammary pirlimycin on the fecal microbiome of dairy cattle. Primiparous heifers were enrolled and assigned to a treatment or control group at a ratio of 2:1. In part 1 of the study, treated heifers (T1) were given intramammary pirlimycin into one infected quarter once daily for 2 d at 24-h intervals, according to the label instructions. Control heifers received no treatment. In part 2 of the study, treated heifers (T2) were given intramammary pirlimycin into one infected quarter once daily for 8 d at 24-h intervals, according to the label instructions. All enrolled heifers (T1, T2, and control) had quarter-level milk samples aseptically collected for bacterial culture and fecal samples collected for 16S rRNA gene sequencing on d 0, 2, 7, 14, 21, and 28. Milk samples were plated on Columbia blood agar and incubated at 37°C for 24 h. Bacteria were identified using MALDI-TOF mass spectrometry. The DNA was extracted from feces using PowerFecal kits (Qiagen, Venlo, the Netherlands). The 16S rRNA gene amplicon library construction and sequencing was performed at the University of Missouri DNA Core facility. Testing for differences in fecal community composition was performed via one-way permutational multivariate ANOVA of Bray-Curtis and Jaccard similarities using Past 3.13 (https://folk.uio.no/ohammer/past/). Mean total count of operational taxonomic units and Chao1, Shannon, and Simpson α-diversity indices were determined and compared via t-test or Wilcoxon rank sum test. A treatment-dependent effect was present in the observed and predicted richness of feces from cows in the T1 group at d 2 posttreatment. Additionally, intramammary pirlimycin induced a significant change in the composition of the fecal microbiota by d 2 in the treated groups. Based on calculated intra-subject similarities, intramammary pirlimycin was associated with a significant acute change in the fecal microbiota of dairy heifers and that chance reversed when the antimicrobial exposure was brief, but sustained following longer exposure. Overall, intramammary pirlimycin administration affected the fecal microbiome of lactating dairy heifers. Further work is necessary to determine the effect of these changes on the heifer and the dairy environment as well as if treatment is influencing antimicrobial resistance among enteric and environmental bacteria.

Formulation Optimization of Selective Laser Sintering 3D-Printed Tablets of Clindamycin Palmitate Hydrochloride by Response Surface Methodology.

The aims of the current study were to develop and evaluate clindamycin palmitate hydrochloride (CPH) 3D-printed tablets (printlets) manufactured by selective laser sintering (SLS). Optimization of the formulation was performed by studying the effect of formulation and process factors on critical quality attributes of the printlets. The independent factors studied were laser scanning speed, microcrystalline cellulose (MCC), and lactose monohydrate (LMH) concentration. The responses measured were printlets weight, hardness, disintegration time (DT), and dissolution in 30 min. The printlets were characterized for content uniformity, chemical interactions, crystallinity, drug distribution, morphology, and porosity. The laser scanning speed showed statistically significant effects on all the studied dependent responses (p < 0.05). MCC showed statistically significant effects on hardness, DT, and dissolution (p < 0.05), while LMH showed statistically significant effect on hardness and dissolution (p < 0.05). The model was validated by an independent formulation, and empirical values were in close agreement with model-predicted values. X-ray powder diffraction and differential scanning calorimetry data suggested a decrease in crystallinity of the LMH in the printlets. X-ray micro-CT scanning showed porous microstructure of the printlets with a porosity 24.4% and 31.1% for the printlets printed at 200 and 300 mm/s laser speed, respectively. In summary, the SLS method provides an opportunity to fabricate customized dosage forms as per patients' need.

Evaluation of an ionic liquid chiral selector based on clindamycin phosphate in capillary electrophoresis.

Recently, increasing attention has been given to the research on chiral ionic liquids (CILs) in chiral separation field; however, only a few literatures focus on the exploration of CILs as the sole chiral selector. In this study, an ionic liquid chiral selector based on antibiotic, namely tetramethylammonium clindamycin phosphate (TMA-CP), was originally synthesized and subsequently utilized for enantioseparation in capillary electrophoresis (CE). Remarkably improved separations of eight racemic analytes were achieved in TMA-CP system in contrast to the clindamycin phosphate (CP) system. The optimal separation conditions were determinated by systematic experiments on several crucial parameters including the type and proportion of organic modifier, CIL concentration, buffer pH, and applied voltage. Additionally, molecular modeling with AutoDock was applied to probe into the chiral recognition mechanism of the ionic liquid chiral selectors, which well corresponded with the experimental results. It is the first time that antibiotic-based ionic liquid was exploited as favorable sole chiral selector in CE, and this strategy has paved a new way for development of novel ionic liquids chiral selectors based on antibiotics. Graphical abstract.

Staphylococcus aureus related to bovine mastitis in Switzerland: Clonal diversity, virulence gene profiles, and antimicrobial resistance of isolates collected throughout 2017.

Staphylococcus aureus can be associated with subclinical, acute, chronic, and toxic cases of bovine intramammary infections, leading to considerable financial losses for the dairy industry in Switzerland and worldwide. In addition, milk products are one of the most common food categories implicated in staphylococcal food poisoning in humans. Detailed information on the population structure, as well as the virulence and resistance characteristics of Staph. aureus originating from bovine mastitis milk is needed to allow for source attribution and risk assessment of Staph. aureus in a food poisoning context and to improve therapeutic approaches in cattle. Our objective was to assess the population structure, phenotypic resistance patterns, and virulence and resistance gene profiles of Staph. aureus isolates from bovine mastitis milk in Switzerland. To this end, 58 Staph. aureus strains were characterized. The DNA microarray was used to test for the presence or absence of virulence and resistance genes. In addition, minimum inhibitory concentrations of various antimicrobial agents were determined by microdilution. To assess the population structure of the isolates, we determined clonal complexes (CC) using DNA microarray hybridization profiles and performed multilocus sequence typing and spa typing. The strains were assigned to 7 clonal complexes, 10 sequence types, and 11 spa types, with CC705 (43%), CC97 (33%), and CC20 (12%) representing the most common lineages and t529 (43%) and t267 (21%) representing the most common spa types. Only 1 isolate was assigned to CC8, a clonal lineage linked to high within-herd prevalence of mastitis. A total of 14% (n = 8) of strains were classified as resistant to penicillin, and 1 strain each was classified as oxacillin and pirlimycin resistant. Although no clinical breakpoints are available for the combination of kanamycin/cefalexin, growth of all strains was inhibited by the lowest combination of kanamycin/cefalexin concentrations tested (4 µg/mL of kanamycin and 0.4 µg/mL of cefalexin). One strain assigned to CC20, ST389, and t2094 exhibited resistance to penicillin, oxacillin, and pirlimycin as well as intermediate susceptibility to erythromycin and high minimum inhibitory concentration for several antimicrobial agents, for which no breakpoints were available.

Early-lactation extended pirlimycin therapy against naturally acquired Staphylococcus aureus intramammary infections in heifers: A randomized controlled trial.

The primary objective of the current study was to evaluate cure rate following an early-lactation extended intramammary pirlimycin treatment on heifers naturally infected by Staphylococcus aureus. The secondary objective was to assess Petrifilm Staph Express (3M Microbiology, St. Paul, MN) count plate characteristics when used in a protocol for early-lactation detection of infected quarters in heifers. Milk samples were collected from heifers (n = 946) in the first few days following calving (mean = 5 d). Heifers with laboratory-confirmed S. aureus intramammary infection (n = 72) were randomly allocated into 2 groups. The treatment group (n = 54 quarters from 38 heifers) received an intramammary infusion of 50 mg of pirlimycin once per day for 8 consecutive days in infected quarters. The control group (n = 44 quarters from 34 heifers) did not receive any treatment. Treatment success was defined as having negative culture results for S. aureus in all 3 post-treatment quarter milk samples collected on d 17, 24, and 31 post-treatment. Treatment group mammary quarters showed a statistically significant higher cure rate (64.8%) compared with the control group (34.1%). A total of 38% of quarters identified as S. aureus-positive using the Petrifilm Staph Express count plate were in fact identified as non-aureus staphylococci on routine laboratory-based bacteriological culture. The current study demonstrates that a higher cure rate for S. aureus IMI can be achieved in dairy heifers if an extended treatment protocol is put in place soon after calving. Use of Petrifilm Staph Express count plate for identification of S. aureus-infected heifers could lead to unnecessary treatments because of false-positive results.

Fate of Pirlimycin and Antibiotic-Resistant Fecal Coliforms in Field Plots Amended with Dairy Manure or Compost during Vegetable Cultivation.

Identification of agricultural practices that mitigate the environmental dissemination of antibiotics is a key need in reducing the prevalence of antibiotic-resistant bacteria of human health concern. Here, we aimed to compare the effects of crop (lettuce [ L.] or radish [ L.]), soil amendment type (inorganic fertilizer, raw dairy manure, composted dairy manure, or no amendment), and prior antibiotic use history (no antibiotics during previous lactation cycles vs. manure mixed from cows administered pirlimycin or cephapirin) of manure-derived amendments on the incidence of culturable antibiotic-resistant fecal coliforms in agricultural soils through a controlled field-plot experiment. Antibiotic-resistant culturable fecal coliforms were recoverable from soils across all treatments immediately after application, although persistence throughout the experiment varied by antibiotic class and time. The magnitude of observed coliform counts differed by soil amendment type. Compost-amended soils had the highest levels of cephalosporin-resistant fecal coliforms, regardless of whether the cows from which the manure was derived were administered antibiotics. Samples from control plots or those treated with inorganic fertilizer trended toward lower counts of resistant coliforms, although these differences were not statistically significant. No statistical differences were observed between soils that grew leafy (lettuce) versus rooted (radish) crops. Only pirlimycin was detectable past amendment application in raw manure-amended soils, dissipating 12 to 25% by Day 28. Consequently, no quantifiable correlations between coliform count and antibiotic magnitude could be identified. This study demonstrates that antibiotic-resistant fecal coliforms can become elevated in soils receiving manure-derived amendments, but that a variety of factors likely contribute to their long-term persistence under typical field conditions.

In vitro antibiotic susceptibility and biofilm production of Staphylococcus aureus isolates recovered from bovine intramammary infections that persisted or not following extended therapies with cephapirin, pirlimycin or ceftiofur.

Staphylococcus aureus intramammary infections (IMIs) have low cure rates using standard antibiotic treatment and increasing the duration of treatment usually improves therapeutic success. Chronic IMIs are thought to be caused by bacteria presenting a specific virulence phenotype that includes the capacity to produce greater amounts of biofilm. In this study, antibiotic susceptibility and biofilm production by S. aureus isolates recovered from IMIs that were cured or not following an extended therapy with cephapirin, pirlimycin or ceftiofur for 5, 8 and 8 days, respectively, were compared. An isolate was confirmed as from a persistent case (not cured) if the same S. aureus strain was isolated before and after treatment as revealed by the same VNTR profile (variable number of tandem repeats detected by multiplex PCR). The antibiotic minimal inhibitory concentrations (MICs) were determined for these isolates as well as the capacity of the isolates to produce biofilm. Isolates from persistent cases after extended therapy with cephapirin or ceftiofur had higher MICs for these drugs compared to isolates from non-persistent cases (p < 0.05) even though the antibiotic susceptibility breakpoints were not exceeded. Isolates of the ceftiofur study significantly increased their biofilm production in presence of a sub-MIC of ceftiofur (p < 0.05), whereas isolates from the pirlimycin group produced significantly less biofilm in presence of a sub-MIC of pirlimycin (p < 0.001). Relative antibiotic susceptibility of the isolates as well as biofilm production may play a role in the failure of extended therapies. On the other hand, some antibiotics may counteract biofilm formation and improve cure rates.

Management of Severe Acne Vulgaris With Topical Therapy.

Acne vulgaris (acne) is the most common skin disease we see in dermatology practice. Although rare in childhood, severe acne can affect up to 12% of the adolescent population. A chronic disease, it requires both aggressive management and effective maintenance strategies. Oral antibiotics, in combination with topical agents are recommended for treatment, with topical agents being continued as maintenance therapy to minimize resistance and recurrence. However, concerns with systemic side effects have recently resulted in a greater focus on the potential of fixed combination topical therapies to treat severe acne. Here we review the available clinical evidence. There are no studies investigating the use of fixed combination topical therapy exclusively in severe acne. However, studies assessing the treatment of moderate-to-severe acne include subpopulation data in severe patients. Adapalene 0.3%-benzoyl peroxide (BP) 2.5% was found to be effective in patients with severe acne, whereas the fixed combination with a lower concentration of adapalene (0.1%) was no more effective than vehicle. Clindamycin-BP 1.2%/3.75% gel and clindamycin-BP 1.2%/2.5% gel were both found to be effective in severe acne with an apparent BP-dose response. Clindamycin phosphate 1.2%-tretinoin 0.025% demonstrated similar efficacy in severe acne, but with little benefit over individual monads. Realistic topical treatment options now exist for the management of severe acne where patient and physician preference can impact positive outcomes.

J Drugs Dermatol. 2017;16(11):1134-1138.

Fixed Combination of Clindamycin Phosphate 1.2% and Benzoyl Peroxide 3.75% Aqueous Gel: Long-Term Use in Adult Females With Moderate Acne Vulgaris.

OBJECTIVE: To evaluate long-term efficacy and safety of a fixed combination clindamycin phosphate 1.2% and benzoyl peroxide 3.75% (Clindamycin-BP 3.75%) aqueous gel in adult female patients with moderate acne vulgaris.

METHODS: Total of 20 patients, 25-63 years of age (mean [SD], 38 ± 10) with moderate acne (IGA=3) were treated with Clindamycin-BP 3.75% once-daily for 12 weeks. Patients who experienced ≥50% reduction in total lesion count continued treatment for a further 12 weeks. Mean (SD) percent reduction in lesion counts from baseline were assessed at week 4, 8, 12, 18, and 24. In addition, patients who were 'clear' or 'almost clear' were reported at week 12 and 24. Cutaneous tolerability (erythema, dryness, peeling, pruritus, and burning) and oiliness was assessed at baseline and each study visit. Adverse events were assessed throughout the study.

RESULTS: Clindamycin-BP 3.75% demonstrated statistical significant improvement from baseline and between each visit. At week 12, mean percent reduction in inflammatory and noninflammatory lesion counts was 70.6% and 58.6%, respectively. Two patients failed to experience ≥50% lesion reduction by week 12. At week 24, mean percent reductions in inflammatory and noninflammatory lesion counts were 93.8% and 90; 72% of patients were 'clear' or 'almost clear'. Overall the treatment was tolerable. There was one adverse event (sinus infection) that was not treatment-related.

CONCLUSIONS: Clindamycin-BP 3.75% gel demonstrates continued improvement in symptoms of moderate acne over 24 weeks, with good tolerability, demonstrating a clinical benefit of continued clindamycin-BP 3.75% gel as a maintenance therapy for acne in adult female patients.

J Drugs Dermatol. 2017;16(6):543-546.

Pharmacokinetics of intravenous clindamycin phosphate in captive Bennett's wallabies (Macropus rufogriseus).

This study was designed to investigate the pharmacokinetics of clindamycin, a lincosamide antibiotic, in Bennett's wallabies. The pharmacokinetic properties of a single intravenous (IV) dose of clindamycin were determined in six wallabies. A single 20-min IV infusion of 20 mg/kg of clindamycin was administered, followed by blood collection prior to, and up to 12 hr after clindamycin administration. Plasma clindamycin concentrations were determined by high-pressure liquid chromatography (HPLC) with ultraviolet (UV) detection. Pharmacokinetic variables were calculated using a two-compartment model with first order elimination which best fit the data. The mean volume of distribution at steady-state, distribution half-life, and elimination half-life were 898.25 ml/kg, 0.16 hr, 1.79 hr, respectively. No adverse effects were noted after IV administration.

Manure Injection Affects the Fate of Pirlimycin in Surface Runoff and Soil.

Antibiotics used in animal agriculture are of increasing environmental concern due to the potential for increased antibiotic resistance after land application of manure. Manure application technology may affect the environmental behavior of these antibiotics. Therefore, rainfall simulations were conducted on plots receiving three manure treatments (surface application, subsurface injection, and no manure control) to determine the fate and transport of pirlimycin, an antibiotic commonly used in dairy production. Rainfall simulations were conducted immediately and 7 d after application of dairy manure spiked with 128 ng g (wet weight) pirlimycin. Soil samples were collected from all plots at two depths (0-5 and 5-20 cm). For injection plots, soil was collected from injection slits and between slits. Pirlimycin concentrations were higher in soil within the injection slits compared with surface application plots at 0 and 7 d. Pirlimycin concentrations in the 0- to 5-cm depth decreased by 30, 55, and 87% in the injection slit, between injection slits, and surface application plots 7 d after application. Pirlimycin concentrations were 106 ng g in sediment and 4.67 ng mL in water from the surface application plots, which were 21 and 32 times that of the injection plots, respectively. After 7 d, pirlimycin levels in runoff sediment and water decreased 80 to 98%. Surface application resulted in six and three times higher pirlimycin concentrations in water and sediment than injection. These results indicate that pirlimycin is most susceptible to loss immediately after manure application. Thus, injection could be considered a best management practice to prevent loss of antibiotics in surface runoff.

Transfersomal Nanoparticles for Enhanced Transdermal Delivery of Clindamycin.

The aim of this work was to study the potential of delivering clindamycin phosphate, as an efficient antibiotic drug, into a more absorbed, elastic ultradeformable form, transfersomes (TRSs). These vesicles showed an enhanced penetration through ex vivo permeation characters. TRSs were prepared using thin-film hydration method. Furthermore, they were evaluated for their entrapment efficiency, size, zeta potential, and morphology. Also, the prepared TRSs were converted into suitable gel formulation using carbopol 934 and were evaluated for their gel characteristics like pH, viscosity, spreadability, homogeneity, skin irritation, in vitro release, stability, and ex vivo permeation studies in rats. TRSs were efficiently formulated in a stable bilayer vesicle structure. Furthermore, clindamycin phosphate showed higher entrapment efficiency within the TRSs reaching about 93.3% ± 0.8 and has a uniform particle size. Moreover, the TRSs surface had a high negative charge which indicated the stability of the produced vesicles and resistance of aggregation. Clindamycin phosphate showed a significantly higher in vitro release (p < 0.05; ANOVA/Tukey) compared with the control carbopol gel. Furthermore, the transfersomal gel showed a significantly higher (p < 0.05; ANOVA/Tukey) cumulative amount of drug permeation and flux than both the transfersomal suspension and the control carbopol gel. In conclusion, the produced results suggest that TRS-loaded clindamycin are promising carriers for enhanced dermal delivery of clindamycin phosphate.

Clindamycin phosphate 1·2%-benzoyl peroxide 3·0% fixed-dose combination gel has an effective and acceptable safety and tolerability profile for the treatment of acne vulgaris in Japanese patients: a phase III, multicentre, randomised, single-blinded, active-controlled, parallel-group study.

BACKGROUND: A topical fixed-dose clindamycin phosphate 1·2% and benzoyl peroxide 3·0% combination gel (CLNP/BPO 3%) is known to be effective and safe in white people with acne. OBJECTIVES: To evaluate the efficacy and safety of CLNP/BPO 3·0% topically applied once or twice daily vs. CLNP twice daily in Japanese patients with acne. METHODS: Eight hundred patients were randomized to receive CLNP/BPO 3·0% once daily, CLNP/BPO 3·0% twice daily or CLNP twice daily for 12 weeks. Primary endpoints were absolute change in number of total lesions (TLs) from baseline to week 12 to demonstrate the superiority of CLNP/BPO 3·0% twice daily and noninferiority of CLNP/BPO 3·0% once daily vs. CLNP twice daily. Secondary endpoints were absolute and percentage changes in TLs, inflammatory lesions (ILs), noninflammatory lesions (non-ILs) and Investigator's Static Global Assessment (ISGA) score. Safety assessments included adverse events (AEs), laboratory tests, vital signs and local skin tolerability. RESULTS: Change in TL counts from baseline to week 12 for CLNP/BPO 3·0% twice daily was superior to CLNP twice daily (difference -11·0; P < 0·01); CLNP/BPO 3·0% once daily was not inferior to CLNP twice daily (difference -10·3; P < 0·01). Absolute and percentage reductions in TL, IL and non-IL counts and ISGA score were greater for CLNP/BPO 3·0% once or twice daily than for CLNP twice daily with significant differences seen from early on. Most AEs were mild or moderate. The incidence of adverse drug reactions was higher for CLNP/BPO 3·0% once (24·0%) or twice (35·1%) daily than for CLNP twice daily (9·0%). CONCLUSIONS: Compared with CLNP twice daily, CLNP/BPO 3·0% once daily was more effective and CLNP/BPO 3·0% twice daily at least as effective, with an early onset of action and an acceptable safety and tolerability profile in Japanese patients.

Establishment and Evaluation of the Novel Tetramethylammonium-L-Hydroxyproline Chiral Ionic Liquid Synergistic System Based on Clindamycin Phosphate for Enantioseparation by Capillary Electrophoresis.

Much attention has been paid to chiral ionic liquids (ILs) in analytical chemistry, especially its application in capillary electrophoresis (CE) enantioseparation. However, the investigation of chiral ionic liquids synergistic systems based on antibiotic chiral selectors has been reported in only one article. In this work, a novel chiral ionic liquid, tetramethylammonium-L-hydroxyproline (TMA-L-Hyp), was applied for the first time in CE chiral separation to evaluate its potential synergistic effect with clindamycin phosphate (CP) as the chiral selector. As observed, significantly improved separation was obtained in this TMA-L-Hyp/CP synergistic system compared to TMA-L-Hyp or a CP single system. Several primary factors that might influence the separation were investigated, including CP concentration, TMA-L-Hyp concentration, buffer pH, types and concentrations of organic modifier, applied voltage, and capillary temperature. The best results were obtained with a 40 mM borax buffer (pH 7.6) containing 30 mM TMA-L-Hyp, 80 mM CP, and 20% (v/v) methanol, while the applied voltage and temperature were set at 20 kV and 20°C, respectively.

Clindamycin phosphate 1.2% / tretinoin 0.025%: a novel fixed-dose combination treatment for acne vulgaris.

The Global Alliance to Improve Outcomes in Acne Group recommends retinoid-based combination therapy as first-line therapy and the preferred treatment approach for almost all acne patients except those with the most severe disease. Clindamycin 1% (as clindamycin phosphate 1.2%)/tretinoin 0.025% (Clin-RA) is a new fixed-dose retinoid-based combination therapy. The aqueous-based gel formulation of Clin-RA was designed to minimize skin irritation and optimize adherence with the therapy. It contains both solubilized and crystalline tretinoin which allows the retinoid to be slowly released onto the skin surface and decreases the potential for cutaneous irritation. A pooled analysis of three pivotal studies involving 4550 acne patients showed that Clin-RA is well tolerated and effective at treating both inflammatory and non-inflammatory acne lesions. The onset of action of Clin-RA is rapid occurring within 2 weeks of treatment initiation. It is not associated with acne flaring or an increase in clindamycin-resistant Propionibacterium acnes counts. Clin-RA is considered as effective as adapalene 0.1%/benzoyl peroxide (BPO) 2.5%, whereas Clin-RA has a more favourable tolerability profile. Clin-RA may be more effective than clindamycin 1%/BPO 5% at treating non-inflammatory acne lesions since the latter does not contain a retinoid to target comedones. Clin-RA is also easy for patients to handle and apply, and has the advantage of not containing BPO which can bleach hair and fabrics. Taken together, the profile of Clin-RA suggests Clin-RA to be a first-line treatment for patients with facial acne.