Mean centering of ratio spectra and concentration augmented classical least squares in a comparative approach for quantitation of spectrally overlapped bands of antihypertensives in formulations

A Smart Green Spectrophotometric Method for Simultaneous Determination of Severely Overlapped Binary Mixtures Using Normalized Spectrum and Isosbestic Point as Resolving Tools

Background:

The ability of the normalized spectra when used as a divisor and in combination with isosbestic point to resolve complex binary or ternary mixtures, Candesartan and Hydrochlorthiazide binary mixture was taken as a model.

Introduction:

A green simple smart and accurate method using ethanol as a solvent namely simultaneous derivative ratio (SIDD) was applied to prove the power of normalized spectra and isosbestic point as spectrophotometric resolving tools.

Methods:

In the proposed SIDD method, the zero order spectra of drugs were simply manipulated using the normalized spectra of CAN as divisor to obtain the ratio and first derivative spectra in two successive steps. Firstly, the total amplitude at isosbestic point 255.4 nm of the ratio spectra of the mixture was measured representing the total actual concentration of both drugs in the mixture. Then, the first derivative of the ratio spectra was obtained to determine Hydrochlorothiazide concentration at 233 nm. While the concentration of Candesartan was determined subsequently by subtracting the Hydrochlorothiazide concentration calculated after derivatization from the total concentration of both drugs obtained at the ratio spectra before the derivatization step.

Results:

The SIDD was successfully applied for simultaneous determination of both drugs in their pure form or in their binary mixture either in synthetic prepared mixtures or in combined dosage form the adopted method was validated according to the ICH guidelines and the results were found to be within the acceptable limits.

Conclusion:

The adopted method highlighted the important role of normalized spectrum when used as a divisor in addition to the importance of isosbestic point to resolve severely overlapped spectra. All the measurements were carried using ethanol which is considered one of the greenest solvents making the method an environmentally friendly one. the adopted method was validated according to the ICH guidelines and the results were found to be within the acceptable limits.

Clostridium difficile infection in the USA: incidence and associated factors in revision total knee arthroplasty patients

INTRODUCTION

Revision total knee arthroplasty (TKA) procedures performed secondary to periprosthetic joint infection (PJI) are associated with significant morbidity and mortality. These poor outcomes may be further complicated by postoperative infection requiring antibiotics. However, antibiotic overuse may suppress patients' bacterial flora, leading to Clostridium difficile infection (CDI). Therefore, we aimed to study the: (1) incidence; (2) costs; and (3) risk factors associated with CDI in revision TKA patients.

METHODS

The National Inpatient Sample database was queried for individuals diagnosed with PJI who underwent revision TKA between 2009 and 2013 (n = 83,806). Patients who developed CDI during their inpatient stay were identified (n = 799). Logistic regression analysis was conducted to assess the association between hospital- and patient-specific characteristics and the development of CDI.

RESULTS

The incidence of CDI after revision TKA was 1.0%. These patients were older (mean age 69.05 vs. 65.52 years), had greater LOS (median 11 vs. 5 days) and greater costs ($30,612.93 vs. 18,873.75), and experienced higher in-hospital mortality (3.6 vs. 0.5%; p < 0.001 for all) compared to those without infection. Patients with CDI were more likely to be treated in urban, not-for-profit, medium/large hospitals in the Northeast or Midwest (p < 0.05 for all) and to have underlying depression (OR 4.267; p = 0.007) or fluid/electrolyte disorders (OR 3.48; p = 0.001).

CONCLUSION

Although CDI is rare following revision TKA, it can have detrimental consequences. We demonstrate that CDI is associated with longer LOS, higher costs, and greater in-hospital mortality. With increased legislative pressure to lower healthcare expenditures, it is crucial to identify means of preventing costly complications.