A novel and rapid microbiological assay for ciprofoxacin hydrochloride

The present work reports a simple, fast and sensitive microbiological assay applying the turbidimetric method for the determination of ciprofloxacin hydrochloride （CIPRO HC1） in ophthalmic solutions. The validation method yielded good results and included excellent linearity, precision, accuracy and specificity. The bioassay is based on the inhibitory effect of CIPRO HC1 upon the strain of Staphylococcus epMermidis ATCC 12228 used as the test microorganism. The results were ar, ated statistically by analysis of variance （ANOVA） and were found to be linear （r=0.9994, in the range of 14.0-56.0 lag/mL）, precise （intraday RSD %=2.06; interday RSD%=2.30） and accurate （recovery = 99.7%）. The turbidimeaic assay was compared to the UV spectrophotometric and I-IPIX2 methods for the same drug. The tuIbidimetric bioassay described on this paper for determination of ciprofioxacin hydrochloride in ophthalmic solution is an alternative to the physicochemical methods disclosed in the literature and can be used in quality control routine.

Selection of appropriate analytical tools to determine the potency and bioactivity of antibiotics and antibiotic resistance

Antibiotics are the chemotherapeutic agents that kill or inhibit the pathogenic microorganisms.Resistance of microorganism to antibiotics is a growing problem around the world due to indiscriminate and irrational use of antibiotics.In order to overcome the resistance problem and to safely use antibiotics,the correct measurement of potency and bioactivity of antibiotics is essential.Microbiological assay and high performance liquid chromatography（HPLC） method are used to quantify the potency of antibiotics.HPLC method is commonly used for the quantification of potency of antibiotics,but unable to determine the bioactivity;whereas microbiological assay estimates both potency and bioactivity of antibiotics.Additionally,bioassay is used to estimate the effective dose against antibiotic resistant microbes.Simultaneously,microbiological assay addresses the several parameters such as minimal inhibitory concentration（MIC）,minimum bactericidal concentration（MBC）,mutation prevention concentration（MPC） and critical concentration（Ccr） which are used to describe the potency in a more informative way.Microbiological assay is a simple,sensitive,precise and cost effective method which gives reproducible results similar to HPLC.However,the HPLC cannot be a complete substitute for microbiological assay and both methods have their own significance to obtain more realistic and precise results.

Improvement in the dissolution rate and tableting properties of cefuroxime axetil by melt-granulated dispersion and surface adsorption

A combination of melt-granulated dispersion and surface adsorption techniques was used to enhance the dissolution and tableting properties of cefuroxime axetil(CA).Gelucire 50/13 was used as the melt-dispersion carrier and Sylysia 350 was used to adsorb the melt dispersion.Solubility studies showed an 8-fold increase in solubility at a ratio of 1:1.5 for CA:Gelucire 50/13.The minimum quantity of Sylysia 350 required to achieve the desired flowability and compressibility was 0.5 parts of Sylysia 350 per unit of Gelucire 50/13.Phase solubility studies showed negative ΔG_(tr)^(0) values for Gelucire 50/13 at various concentrations(2-10%,vv/v),indicating the spontaneous nature of solubilization.FT-IR and DSC spectra exhibited drug-excipient compatibility.Molecular modeling by a computational method employing energy minimization revealed entrapment of CA in Gelucire 50/13.The total potential energy of CA(70.562 keal/mol)was reduced to 33.578 keal/mol after solid dispersion with Gelucire 50/13.P-XRD studies indicated that the presence of Sylysia 350 is less likely to promote the reversion of the amorphous CA to a crystalline state.In vitro dissolution studies demonstrated an improved dissolution rate,and drug release at 15 min(Q_(15min))exhibited a 15-fold improvement.The rapidly dissolving CA tablets showed improved dissolution with improved tableting properties.