Clindamycin phosphate 1.2%/adapalene 0.15%/benzoyl peroxide 3.1% gel for moderate-to-severe acne: Efficacy and safety results from two randomized phase 3 trials.

BACKGROUND: A three-pronged acne treatment approach-combining an antibiotic, antibacterial agent, and retinoid-may provide greater efficacy than single/double treatments. Topical clindamycin phosphate 1.2%/adapalene 0.15%/benzoyl peroxide (BPO) 3.1% gel (IDP-126) is the first fixed-dose triple-combination in development for acne. OBJECTIVE: To confirm efficacy, safety, and tolerability of IDP-126 gel in acne treatment. METHODS: Two phase 3, double-blind, 12-week studies randomized participants aged ≥9 years with moderate-to-severe acne (N = 183; N = 180) 2:1 to once-daily IDP-126 or vehicle gel. Co-primary endpoints comprised participants achieving ≥2-grade reduction from baseline in Evaluator's Global Severity Score (EGSS) and clear/almost clear skin (treatment success) and change from baseline in inflammatory/noninflammatory lesion counts. Treatment-emergent adverse events (TEAEs) were assessed. RESULTS: At week 12, 49.6% and 50.5% of participants achieved treatment success with IDP-126 versus 24.9% and 20.5% with vehicle (P < .01, both). IDP-126 also provided significantly greater reductions in inflammatory/noninflammatory lesions versus vehicle (least-squares mean percent range: 72.7% to 80.1% vs 47.6% to 59.6%; P < .001, all). Most TEAEs were of mild-moderate severity. LIMITATIONS: Inter-observer bias/variation in acne severity ratings, limited treatment duration, and population differences that may not generalize to real-world populations. CONCLUSION: The innovative fixed-dose, triple-combination IDP-126 gel was efficacious and well tolerated in 2 clinical studies of participants with moderate-to-severe acne.

Clindamycin phosphate and bone morphogenetic protein-7 loaded combined nanoparticle-graft and nanoparticle-film formulations for alveolar bone regeneration - An in vitro and in vivo evaluation.

Commonly utilized techniques for healing alveolar bone destruction such as the use of growth factors, suffering from short half-life, application difficulties, and the ability to achieve bioactivity only in the presence of high doses of growth factor. The sustained release of growth factors through a scaffold-based delivery system offers a promising and innovative tool in dentistry. Furthermore, it is suggested to guide the host response by using antimicrobials together with growth factors to prevent recovery and achieve ideal regeneration. Herein, the aim was to prepare and an in vitro - in vivo evaluation of bone morphogenetic protein 7 (BMP-7) and clindamycin phosphate (CDP) loaded polymeric nanoparticles, and their loading into the alginate-chitosan polyelectrolyte complex film or alloplastic graft to accelerate hard tissue regeneration. PLGA nanoparticles containing CDP and BMP-7, separately or together, were prepared using the double emulsion solvent evaporation technique. Through in vitro assays, it was revealed that spherical particles were homogeneously distributed in the combination formulations, and sustained release could be achieved for >12 weeks with all formulations. Also, results from the micro-CT and histopathological analyses indicated that CDP and BMP-7 loaded nanoparticle-film formulations were more effective in treatment than the nanoparticle loaded grafts.

A Pilot Study of Clindamycin Phosphate 1.2% and Benzoyl Peroxide 3.75% Combination Gel in the Treatment of Perimenstrual Acne.

Background: The current mainstay treatment of perimenstrual acne consists of systemic hormonal therapies, which can be problematic due to their side effects, stigma, or pill burden. Topical treatments are often used as well; however, data on their efficacy in treating this type of hormonal acne are limited. Objective: We sought to evaluate the efficacy and tolerability of clindamycin phosphate and benzoyl peroxide 1.2%/3.75% combination gel in treating perimenstrual acne in adult women. Methods: The single-group interventional pilot study was performed on 22 adult female subjects with perimenstrual acne. The subjects applied the investigational drug daily and were assessed every 14 days for a total of 99 days. Treatment success was evaluated by the investigators using the acne physician global assessment (PGA) scoring system. Drug tolerability assessment was based on the subject-reported adverse events, as well as physician-evaluated erythema, scaling, and dryness. Results: The study demonstrated a significant improvement in PGA score and lesion count, as well as patient-reported outcomes. The medication was well-tolerated in all subjects. Limitations: Limited sample size; lack of concurrent comparison group. Conclusion: Clindamycin phosphate and benzoyl peroxide 1.2%/3.75% combination gel presents an important topical option for perimenstrual acne.

Efficacy and tolerability of three topical acne treatments by body mass index: post hoc analysis including overweight and obese patients.

BACKGROUND: Acne prevalence may be higher in overweight/obese individuals, potentially due to hormonal, inflammatory, and/or dietary factors. However, the effects of body mass index (BMI) on topical acne treatments are largely unknown. METHODS: Post hoc analyses of changes in inflammatory/noninflammatory lesions and treatment success were conducted using phase 3 data: clindamycin phosphate/benzoyl peroxide (CP/BPO) 1.2%/3.75% gel (NCT01701024); tretinoin 0.05% lotion (NCT02965456 and NCT02932306; pooled); and tazarotene 0.045% lotion (NCT03168321 and NCT03168334; pooled). Data were analyzed by BMI subgroups: <25kg/m2 (underweight-to-normal), 25-<30kg/m2 (overweight), and ≥30kg/m2 (obese). RESULTS: Among participants analyzed (CP/BPO = 495; tretinoin = 1,636; tazarotene = 1,612), ∼20-25% were overweight and 15-20% were obese. At week 12, mean percent changes from baseline in inflammatory lesions were: CP/BPO (overweight: -63.2%, obese: -56.0%); tretinoin (-57.6%, -53.1%); tazarotene (-59.9%, -56.8%). Mean changes in noninflammatory lesions were: CP/BPO (-54.2%, -50.8%); tretinoin (-51.6%, -44.9%); tazarotene (-56.7%, -54.6%). Treatment success rates with active treatment ranged from 16.2% to 33.5% across BMI groups. CONCLUSIONS: CP/BPO 1.2%/3.75% gel, tretinoin 0.05% lotion, and tazarotene 0.045% lotion were all effective in reducing acne lesions by ≥45% in overweight/obese patients with moderate-to-severe acne, comparable to the underweight-to-normal group. Efficacy of these topical acne treatments is not greatly impacted by BMI and may be affected more by the formulation.

Nanostructured lipid carriers for hair follicle-targeted delivery of clindamycin and rifampicin to hidradenitis suppurativa treatment.

Hidradenitis suppurativa is a chronic and debilitating inflammatory condition related to a permanent obstruction of the pilosebaceous units. Until nowadays, therapeutic options are unsatisfactory. Here, we propose nanostructured lipid carriers (NLC) entrapping an association of clindamycin phosphate (CDM) and rifampicin (RIF) as a topical alternative for the treatment of the disease. Chemical compatibility between the drugs was demonstrated using thermal analysis combined with ATR-FTIR and X-ray powder diffraction assays. Nanocarriers' diameter was narrowly distributed (polydispersity index = 0.2) around 400 ± 14 nm, they possess a negative surface charge (-48.9 ± 0.7 mV) and high drug entrapment efficiencies (80.2 ± 0.4 % and 93.4 ± 0.7 % for CDM and RIF, respectively). The formulation proved to be safe for the topical application, as it was non-irritant on both HET-CAM and reconstructed human epidermis (RHE) assays. Spin-label EPR indicated an NLC affinity for the lipidic domains of stratum corneum, which could benefit the targeting of the sebaceous units. Indeed, when applied on the skin in vitro, even when mimicking the sebaceous condition, NLC accumulated into the hair follicles openings, not altering the amount of accumulated CDM and significantly increasing by 12-fold the uptake of RIF in these structures. In conclusion, developed NLC formulation incorporating the antibiotics CDM and RIF is a promising strategy for the topical treatment of hidradenitis suppurativa or other infections that may affect the pilosebaceous units.

Simultaneous determination of tazarotene, clindamycin phosphate and their active metabolites in Bama mini-pig skin by LC-MS/MS: Application to the development of a tazarotene/clindamycin phosphate cream.

Topical tazarotene combined with clindamycin phosphate can significantly improve the adherence and outcomes for the treatment of acne vulgaris than monotherapy, a novel tazarotene (0.05%)/clindamycin phosphate (1.2%) cream is thus developed. However, the pharmacokinetics and potential interaction of tazarotene and clindamycin phosphate in skin when formulated together remain unknown, which should be investigated to assess this novel cream. In the present work, a sensitive and rapid LC-MS/MS method for simultaneous determination of tazarotene, clindamycin phosphate and their active metabolites tazarotenic acid, clindamycin in Bama mini-pig skin was developed and reported for the first time. After pretreatment of the skin samples, the analytes were well separated on a Hypersil BDS C8 column (4.6 × 100 mm, 2.4 µm) using 0.2% (v/v) formic acid-0.1% (w/v) ammonium acetate water solution and acetonitrile as mobile phase in linear gradient elution. Quantification of tazarotene, clindamycin phosphate and their active metabolites tazarotenic acid, clindamycin was conducted under positive electrospray ionization mode using multiple reactions monitoring detection. The LC-MS/MS method was fully validated and then applied to the dermal pharmacokinetic study of the tazarotene/clindamycin phosphate cream. According to the obtained results, tazarotene and clindamycin phosphate did not have any drug-drug interaction when they were formulated together in the cream for topical application. Their absorption and metabolism features in the skin were also characterized, which can support the clinical medication regimen of tazarotene/clindamycin phosphate cream.

Determination of Clindamycin Phosphate and Clindamycin in Long-Circulating Autologous Erythrocyte-Based Drug by HPLC / 中国药学杂志

OBJECTIVE: To establish a high performance liquid chromatography (HPLC) method to determine the contents of clindamycin phosphate and clindamycin in long-circulating autologous erythrocyte-based drug. METHODS: Clindamycin phosphate and clindamycin were determined by HPLC with Shimadzu Shim-pack VP-ODS chromatographic column (4.6 mm×250 mm, 5 μm) and Waters Symmetry C18 precolumn(3.9 mm×22 mm, 5 μm). The internal standard was nipagin ester. The mobile phase was composed of 0.062 5 mol•L-1 KH2PO4 and acetonitrile at 65∶35 (V/V) at a flow rate of 1.0 mL•min-1. The column temperature was maintained at 25 ℃ and the detection wavelength was set at 210 nm. RESULTS: The calibration curve of clindamycin phosphate showed good linearity in the range of 0.253-506 μg•mL-1, and the calibration curve of clindamycin showed good linearity in the range of 0.251-502 μg•mL-1. The average recovery was more than 98%. The test solution was stable at 4 ℃ and room temperature for 24 h, and the precision met requirements. CONCLUSION: The method is simple, specific, accurate and stable, which is suitable for the determination of clindamycin phosphate and clindamycin in long-circulating autologous erythrocyte-based drug.

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.

Preparation and evaluation of clindamycin phosphate loaded chitosan/alginate polyelectrolyte complex film as mucoadhesive drug delivery system for periodontal therapy.

In this study, Clindamycin phosphate loaded adhesive polyelectrolyte complex films for local periodontal therapy were prepared with alginate and chitosan. The thickness, drug content, structure, swelling, adhesion and in vitro drug release with release kinetics of formulations were evaluated. The effects of the varying concentration and molecular weight of polymers used and the volume of the polymer solutions on the characteristics of the films were investigated. Increasing the concentration of sodium alginate in total content of polymer mixture caused to higher adhesiveness. Chitosan molecular weight also affected to adhesiveness of complex films. The release rate of drug and release kinetics was affected from the complexation. The best complexation was obtained with the three times higher concentration and volume of alginate in combination with low molecular weight chitosan. Thus polyelectrolyte films that have delayed release together with high swelling ability and adhesiveness and high drug content were formed. Due to the heterogeneous structure of complex film, the release profiles of the formulations fitted to the anomalous transport mechanism. 3D structure of the drug loaded complex film was analyzed by Micro-CT imaging in this study and it was showed that using this method would be very advantageous for further studies about the investigation of complexation than the other imaging methods in order to determine the volume and the size of the formed complexes within the structure at the same time.

Development and validation of a simple chromatographic method for simultaneous determination of clindamycin phosphate and rifampicin in skin permeation studies.

Rifampicin (RIF) and clindamycin phosphate (CDM) are the main drugs currently used in combination to treat severe infectious diseases in hair follicles. This work describes a simple, rapid and sensitive method for simultaneous analysis of RIF and CDM in the different skin layers using high performance liquid chromatography (HPLC). The efficient chromatographic separation of CDM and RIF was succeeded using a C18 column (150 mm x 4.6 mm, 5 µm) with gradient elution using a mobile phase composed of 0.01 M phosphoric acid and methanol at a flow rate of 1 mL min-1. Determinations were performed using UV-vis detector at 200 nm and 238 nm for CDM and RIF, respectively. The method was precise, accurate and linear (r2 > 0.999) with regression curve in the concentration range from 0.5 to 20.0 µg mL-1 and recovery rates from the skin layers higher than 85%. The retention times for CDM and RIF were approximately 7.4 and 12.2 min, respectively. The presence of skin components did not interfere with the analysis. The validated method was therefore appropriate for quantification of both CDM and RIF and thus may be feasible to be used in skin permeation studies.

An ecofriendly green liquid chromatographic method for simultaneous determination of nicotinamide and clindamycin phosphate in pharmaceutical gel for acne treatment.

A new green micellar liquid chromatographic method was developed and validated for the quantitative estimation of nicotinamide (NICO) and clindamycin phosphate (CLD) in bulk and pharmaceutical gel formulation. The analytes are well resolved in less than 6.0 minutes using micellar mobile phase consisting of 0.10M sodium dodecyl sulfate (SDS), 0.3% triethylamine, and 10% 2-propanol in 0.02M orthophosphoric acid at pH 3.0, running through an Eclipse XDB-C8 column (150 mm×4.6 mm, 5 µm particle size) with flow rate 1.0 mL/min. The effluent was monitored with diode array detection at 210 nm. The retention times of NICO and CLD were 3.8 minutes and 5.6 minutes, respectively. The method was validated according to the International Conference on Harmonisation (ICH) guidelines in terms of linearity, limit of detection, limit of quantification, accuracy, precision, robustness, and specificity to prove its reliability. Linear correlation was achieved by plotting the peak area of each drug against its concentration. It was found to be rectilinear in the ranges of 1.0-40.0 µg/mL and 0.5-15.0 µg/mL with limits of detection of 0.06 µg/mL and 0.03 µg/mL and limits of quantification of 0.19 µg/mL and 0.09 µg/mL for NICO and CLD, respectively. The method was successfully implemented for the simultaneous determination of the analytes in their bulk powder and combined gel formulation with high % recoveries. The ease of sample treatment facilitates and greatly expedites the treatment with reduced cost and improved accuracy of the procedure.

Efficacy, tolerability and impact on quality of life of clindamycin phosphate and benzoyl peroxide for the treatment of cetuximab-associated acneiform eruption in patients with metastatic colorectal cancer.

BACKGROUND: Epidermal growth factor receptor inhibitors are recent antineoplastic treatments used for the treatment of some non-cutaneous tumours, which aberrantly express EGFR. Because of their specificity, these drugs have low systemic toxicity, but frequent undesired cutaneous effects, the most common of which is an acneiform eruption, occurring after 1-3 weeks of treatment. Management of this rash is not well standardized. OBJECTIVE: We evaluated efficacy, tolerability and impact on quality of life of a clindamycin phosphate 1.2%-benzoyl peroxide 5% gel in 12 male adults who developed acneiform eruption during treatment with cetuximab for metastatic colorectal cancer. METHODS: Patients applied the clindamycin phosphate-benzoyl peroxide gel once daily, at evening, for 8 weeks. The Skin-Score was used to evaluate reduction of erythema, papules, pustules and pruritus, the Dermatology Life Quality Index questionnaire to evaluate the improvements of health-related quality of life. RESULTS: Significant clinical improvements occurred after 2 weeks of treatment and were even more evident after 8 weeks (mean Skin-Score 20.54 ± 7.83, p = 1.37 × 10(-6) vs. second week visit, p = 1.26 × 10(-7) vs. before treatment). Accordingly, DLQI values decreased from 13.64 ± 2.01 before treatment to 6.45 ± 1.37 after 8 weeks (p = 1.12 × 10(-5)). CONCLUSION: A clindamycin phosphate-benzoyl peroxide gel may be an effective and safe option in the treatment of cetuximab-associated acneiform eruptions.

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.

Investigation of the Item Labeling in the Instructions of Domestic Clindamycin Phosphate Injection / 中国药房

OBJECTIVE:To provide reference for the instructions of domestic Clindamycin phosphate injection. METHODS:The contents in the instructions of domestic Clindamycin phosphate injection approved the listing from Jan. 2006 to Dec. 2015 were statistically investigated according to Regulation for Drug Package Inserts and Label Management and Regulatory Guidelines for Chemicals and Biologicals,and the items with great differences in different approval number were analyzed comparatively. RE-SULTS:The labeling rate of clinical experiment in the collected 25 instructions of domestic Clindamycin phosphate injection was 0,the labeling rate of validity was 44%,the labeling rate of use for elderly patients was 68%,the labeling rate of overdosage was 76%,and the labeling rate of others was 100%. The items with great differences were mainly special populations,usage and dos-age,adverse reactions,validity,storage conditions and precautions. CONCLUSIONS:There are great differences in instructions of domestic Clindamycin phosphate injection,some items are inaccurate,incomplete and lack of scientificity,which may result in ir-rational drug use in patients and increase the risk of medication. It is suggested that the domestic enterprises should modify and per-fect the contents of the instructions of domestic Clindamycin phosphate injections referring to the instructions of foreign brand name drug;and the drug regulatory department should strengthen the monitoring of drug instructions.

Analysis the Application of Clindamycin Phosphate for Injection for Inpatients in A Third Grade Class A Hos-pital / 中国药房

OBJECTIVE:To investigate the application of clindamycin phosphate for inpatients in a third grade class A hospital, and provide reference for the specication of its application. METHODS:Retrospective investigation was adopted to randomly obtain the medical information of inpatients who used Clindamycin phosphate for injection in a third grade class A hospital in May 2014, and its rationality was evaluated and analyzed by referred the instructions,relevant provisions and principles. RESULTS:Totally 205 patients used Clindamycin phosphate for injection,among which 174 were for the purpose of prevention medicine,31 cases for treatment purposes. There were reasonable use of 130 cases(63.4%);unreasonable prophylaxis of 71 cases(34.6%),unreason-able treatment of 4 cases(2.0%),it was mainly no indication of medicine,usage and dosage,treatment course and use of antibac-terial drugs. CONCLUSIONS:There still remains unreasonable phenomenon in the clinical application of the Clindamycin phos-phate for injection,the safe and effective clinical application can only be ensured if the drug regulatory system is improved and anti-bacterial drugs in clinical medicine guidelines is strictly enforced.

Thermoanalytical characterization of clindamycin-loaded intravitreal implants prepared by hot melt extrusion.

BACKGROUND: The aim of the present study was to evaluate a non-destructive fabrication method in for the development of sustained-release poly (L, D-lactic acid)-based biodegradable clindamycin phosphate implants for the treatment of ocular toxoplasmosis. MATERIALS AND METHODS: The rod-shaped intravitreal implants with an average length of 5 mm and a diameter of 0.4 mm were evaluated for their physicochemical parameters. Scanning electron microscopy (SEM), differential scanning calorimetry (DSC), Fourier-transform infrared (FTIR), and nuclear magnetic resonance (1H NMR) studies were employed in order to study the characteristics of these formulations. RESULTS: Drug content uniformity test confirmed the uniformity in different implant batches. Furthermore, the DSC, FTIR, and 1H NMR studies proved that the fabrication process did not have any destructive effects either on the drug or on the polymer structures. CONCLUSION: These studies showed that the developed sustained-release implants could be of interest for long-term sustained intraocular delivery of clindamycin, which can provide better patient compliance and also have good potential in terms of industrial feasibility.

Design and development of intraocular polymeric implant systems for long-term controlled-release of clindamycin phosphate for toxoplasmic retinochoroiditis.

BACKGROUND: The release of the anti-toxoplasmosis drug, clindamycin phosphate, from intraocular implants of the biodegradable polymers poly (D, L-lactic acid) (PLA) and poly (D, L-lactide-co-glycolide) (PLGA) has been studied in vitro. MATERIALS AND METHODS: The preparation of the implants was performed by a melt-extrusion method. The developed extrudates were characterized and compared in in-vitro release profiles for elucidating the drug release mechanism. The formulations containing up to 40% w/w of drug were prepared. Release data in phosphate buffer (pH 7.4) were analyzed by high performance liquid chromatography. The release kinetics were fitted to the zero-order, Higuchi's square-root, first order and the Korsmeyer-Peppas empirical equations for the estimation of various parameters of the drug release curves. Degradation of implants was also investigated morphologically with time (Scanning Electron Microscopy). RESULTS: It was observed that, the release profiles for the formulations exhibit a typical biphasic profile for bulk-eroding systems, characterized by a first phase of burst release (in first 24 hrs), followed by a phase of slower release. The duration of the secondary phase was found to be proportional to the molecular weight and monomer ratio of copolymers and also polymer-to-drug ratios. It was confirmed that Higuchi and first-order kinetics were the predominant release mechanisms than zero order kinetic. The Korsmeyer-Peppas exponent (n) ranged between 0.10 and 0.96. This value, confirmed fickian as the dominant mechanism for PLA formulations (n ≤ 0.45) and the anomalous mechanism, for PLGAs (0.45 < n < 0.90). CONCLUSION: The implant of PLA (I.V. 0.2) containing 20% w/w of clindamycin, was identified as the optimum formulation in providing continuous efficient in-vitro release of clindamycin for about 5 weeks.

Determination of Clindamycin Phosphate in Compound Sodium Phenytoin Gels by HPLC / 中国药师

Objective:To establish an HPLC method for the determination of clindamycin phosphate in compound phenytoin sodi-um ge1s. Methods:The HPLC analysis was carried out on a ZORBAX SB-C18 column(250 × 46 mm,5 μm)with 0. 1 mol·L-1 KH2PO4 solution(adjusting pH to 2. 5 with H3PO4 solution)-acetonitrile(75:25)as the mobile phase at the flow rate of 0. 8 ml· min-1 . The detection wavelength was 210 nm,the column temperature was 25℃ and the injection volume was 10μl. Results:The lin-ear range of clindamycin phosphate was 3. 00-18. 00 μg(r=0. 999 5). The average recovery was 101. 11%(RSD=0. 34%,n=6). Conclusion:The method is simple,sensitive and reproducible,and can be used in the determination of clindamycin phosphate in com-pound phenytoin sodium gels.

Multi-spectral characterization & effect of metal ions on the binding of bovine serum albumin upon interaction with a lincosamide antibiotic drug, clindamycin phosphate.

The interaction of clindamycin phosphate (CP) with bovine serum albumin (BSA) is studied by using fluorescence spectra, UV-visible absorption, synchronous fluorescence spectra (SFS), CD, 3D fluorescence spectra and lifetime measurements under simulated physiological conditions. CP effectively quenched intrinsic fluorescence of BSA. The binding constants KA values are 2.540×10(5), 4.960×10(5), 7.207×10(5) L mol(-1), the number of binding sites n and corresponding thermodynamic parameters ΔG(o), ΔH(o) and ΔS(o) between CP and BSA were calculated at different temperatures. The interaction between CP and BSA occurs through dynamic quenching and the effect of CP on the conformation of BSA was also analyzed using SFS. The average binding distance r between the donor (BSA) and acceptor (CP) was determined based on Förster's theory. The results of fluorescence spectra, UV-vis absorption spectra and SFS show that the secondary structure of the protein has been changed in the presence of CP.

Enantioseparation of basic chiral compounds on a clindamycin phosphate-silica/zirconia hybrid monolith by capillary electrochromatography.

An organic-inorganic silica/zirconia hybrid monolithic capillary column was prepared by sol-gel process in a fused-silica capillary by using triethoxysilylpropylcarbamate (TEOSPC) derivative of clindamycin phosphate (CLIP) as a chiral selector. A sol solution consisting of 6 × 10(-3)M of polyethylene glycol, 1 M of water, 2M of acetic acid and 0.04/0.96 ratio of CLIP-TEOSPC/Zr-Bu resulted in homogeneous monolith having well defined through-pores and tightly anchored to the capillary wall. The column was employed for capillary electrochromatographic enantioseparation of eight basic chiral drugs in mobile phases consisting of acetonitrile, methanol and ammonium acetate (AA, as the electrolyte). Effects of the compositions of solvents and electrolyte in the mobile phase, applied voltage and capillary temperature on chiral separation were investigated. The highest resolution values were obtained with mobile phases consisting of 40/60 MeOH/ACN and 100 mM AA (for citalopram, Tröger's base, indapamide, metoprolol, cetirizine and atropine) and 35/65 MeOH/ACN and 100 mM AA (for sertraline and propranolol) using -10 kV applied voltage at 25 °C.