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Introduction Musculoskeletal (MSK) disorders are one of the common health issues affecting people of various ages. The main risk factors for musculoskeletal pain are age, obesity, gender, level of education, psychosocial factors, occupational factors, decreased mobility and flexibility, and common factors such as consuming TV and video games. College students, especially medical students, are at a higher risk of these complaints as they have longer hours of studying than most faculties due to the competitiveness of their specialty. The objective of this study was to identify the relationship between musculoskeletal pain and studying hours in medical students in Jeddah, Saudi Arabia, and to increase awareness of this problem. Methods This cross-sectional study was conducted in 2022. Data was collected using an online questionnaire. A total of 314 participants were included in this study. The demographic variables, studying hours, studying locations, and postures were collected and analyzed. Results A total of 314 medical students were included in this study. The majority were males (71.0%) and, the mean age was 22.05±2.13 years. Most of them were sixth-year students, and most of them reported studying between three and four hours (40.1%), with the most common studying location reported being the students' home or residence (79.3%). The number of daily studying hours had no significant effect on the occurrence of musculoskeletal problems. Conclusion There was no significant relationship between the number of studying hours and the MSK pain. Clinical trials could be used to evaluate the most effective approaches to alleviate MSK pain in medical students., Competing Interests: The authors have declared that no competing interests exist., (Copyright © 2023, Abumohssin et al.)

Background Over the previous decade, the incidence of cardiovascular diseases (CVDs) has risen in the Middle East and will increase mortality to 23 million individuals in Saudi Arabia by 2030, according to the Saudi Ministry of Health. CVDs, including acute coronary syndrome (ACS), are the most common cause of mortality globally. This study aimed to analyze the demographic and clinical characteristics of patients with ACS admitted to the coronary care unit (CCU) in a tertiary hospital in Jeddah, Saudi Arabia. To the best of our knowledge, a lack of research in this region has been undertaken. Methods This retrospective records review study was conducted in a tertiary center in Jeddah, Saudi Arabia. All patients admitted to our CCU in 2017 with a final diagnosis of ACS were retrospectively enrolled. Demographic details, coronary risk factors, investigation and procedures, management, and clinical outcomes are all part of the data. Results Of the 615 patients included in the study, 491 (79.84%) were males, 226 (36.75%) were 55-64 years old, and 161 (26.18%) were 45-54 years old. Males had a higher rate of ST-segment elevation myocardial infarction (STEMI) (214, 43.58%), while females had a higher rate of non-ST-segment elevation myocardial infarction (NSTEMI) and unstable angina (UA) (45.96% and 37.90%, respectively). Diabetes (62.60%), dyslipidemia (62.44%), and hypertension (61.46%) were the most prevalent risk factors. Angiography and percutaneous coronary intervention (PCI) were performed in 77.72% and 61.95% of patients, respectively. Coronary artery bypass graft was only performed in 4.39% of patients. PCI was performed more frequently in patients with STEMI than in those with NSTEMI/UA (P < 0.001). A large majority of patients (99.5%) recovered and were discharged. Of the 161 (26.18%) patients who attended a follow-up visit, only 45 (33.08%) met the therapeutic objective of 1.8 mmol/L (70 mg/dl) of low-density lipoprotein cholesterol. There were 100 (16.26%) patients readmitted to the CCU, and most of these were readmitted within a year after initial admission. Readmissions were more common in females and patients diagnosed with NSTEMI/UA during initial admission (15.47% and 19.35%, respectively). Conclusion This study revealed that our most common demographics were males between 45 and 64 years, which is a decade younger than the global average. STEMI was the most common presentation. The most common modifiable cardiovascular risk factors were hypertension, diabetes, and dyslipidemia. The most common adverse event was reinfarction, which was closely linked to hypertension and diabetes. In this study, the recovery rate was higher than in studies from other countries; however, the majority of patients did not achieve the goal of cholesterol levels at follow-up. Our population's younger age at presentation necessitates greater attention and more stringent preventive strategies, such as lifestyle changes and evidence-based treatments for CVD risk factors, to reduce the incidence and burden of ACS on CCUs., Competing Interests: The authors have declared that no competing interests exist., (Copyright © 2022, Takieddin et al.)

Objectives: Dental caries are associated with high counts of S treptococcus mutans (SM) and Lactobacillus (LB) and low saliva buffering capacity (BC). This study aimed to evaluate the antimicrobial activity of black tea on salivary cariogenic microflora, SM and LB species in an adult population. Antimicrobial activity was measured from the number of colony forming units (CFUs) of SM and LB, and BC of saliva., Methods: In this prospective experimental study, unstimulated saliva samples were acquired from the participants before, immediately after, and 1 h after drinking tea by collecting saliva in sterilised containers. Samples were taken to the laboratory for incubation and subsequent counting. SM and LB counts and BC of saliva were calculated using the caries risk test (CRT)., Results: A total of 21 participants, 13 males and 8 females, with a mean age of 32.6 ± 8.02, were recruited in this study. Black tea had no significant effect on reducing the cariogenic bacterial counts ( p  > 0.05)., Conclusion: Based on this study, it can be deduced that black tea exhibits an insignificant antimicrobial effect against Streptococcus mutans and Lactobacillus bacteria.

Objective: Self-medication can be defined as the practice of using drugs that have not been prescribed, recommended, or controlled by a certified health-care professional. This term can be used when discussing patients who use non-prescription medications to treat self-diagnosed disorders or symptoms, without consulting a medical practitioner and without any medical supervision. The objectives of this study are to identify patterns of self-medication in Saudi Arabia, to measure the association between gender and the use of non-prescribed medication, and to identify the type of medications involved, the dosages used, and patient's sources of knowledge regarding the types, and doses of medications., Method: Cross-section analytical observational study, conducted in Al Medina city, Saudi Arabia, over 6 months using a pretested self-administered questionnaire using a convenience sampling technique., Results: With a response rate of 68.8%, it was found that 72.5% reported the use of non-prescribed medication and 24.3% reported a history of experiencing side effects from using non-prescribed medication with no significant difference between male and female. 81% were keen to read the medication instruction with higher response among females.Analgesics were the most common type of medication used with an 86.5% agreement with no statistical significant differences between male and females., Conclusion: The study found heavy use of non-prescribed medication among the Al Medina residents sampled. This suggests a need for specialist training programs that could be directed at pharmacists, to help them disseminate information on the safe use of OTC or non-prescribed medications.

Objectives: Safety culture assessments allow healthcare organisations to get a clear understanding of those aspects of patient safety requiring urgent attention and highlight safety culture strengths and weaknesses. This study aimed to evaluate the extent to which the culture supports patient safety at a hospital in KSA., Methods: A cross-section analytical observational study was conducted at King Fahad Hospital in Almadinah Almunawwarah, KSA., Results: After the survey, the staff felt less certain about the patient safety culture inside the institution. The greatest positive scores were obtained for teamwork within units, safety culture composites, feedback, communication about error, management expectations, actions promoting patient safety, organisational learning, and continuous improvement. However, none of these features achieved a positive score of 75% or more as an area of strength. The rest of the aspects were negatively ranked as areas for probable development, with the lowest scores obtained for non-punitive reaction to error, staffing, hospital handoff and transition, communication openness, and hospital management support for patient safety., Conclusion: Commitment to quality care as an outcome is certainly correlated with patient safety. There is a strong need to improve and promote applicable policies to improve the culture of patient safety in hospitals. The development of strong management competence to promote an environment of open consultation and administrative wisdom will contribute to improving patient safety culture.

This work describes five simple and reliable spectrophotometric and chromatographic methods for analysis of hepatitis C antiviral binary mixture of ledipasvir (LPV) and sofosbuvir (SBV). Method I is based on the use of A max and derivative spectrophotometry with the zero-crossing technique where LPV was determined using its A max and 1 D amplitudes at 324 and 338nm respectively, while SBV was determined by measuring the 1 D amplitudes at 276nm. Method II involves the application of the ratio spectra derivative spectrophotometry. For LPV, 12μg/mL SBV was used as divisor and the 1 DD amplitudes at 239.8nm were plotted against LPV concentrations; while by using 10μg/mL LPV, the amplitudes at 279.2nm were found proportional to SBV concentrations. Method III depends on ratio-difference measurement where the peak to trough amplitudes between 229.2 and 268.4nm were measured and correlated to LPV concentration. Similarly, the amplitudes between 268.6 and 229.2nm in the SBV ratio spectra were recorded. For method IV, the two compounds were separated using HPTLC sheets of silica gel and a mobile phase composed of chloroform-methanol (94:6) followed by densitometric measurement of LPV and SBV spots at 331 and 267nm respectively. Method V depends on HPLC-DAD. Effective chromatographic separation was achieved using Thermohypersil C8 column (4.6×250mm, 5μm) with a mobile phase consisting of 0.01M sodium dihydrogen phosphate (pH 2.5) and methanol (20:80) at a flow rate 1.2mL/min and detection at 332 and 262nm for LPV and SBV respectively. Analytical performance of the developed methods was validated according to the ICH guidelines with respect to linearity, ranges, precision, accuracy, detection and quantification limits. The validated methods were successfully applied to the simultaneous analysis of LPV and SBV in mixtures of different proportions and their combined tablet dosage form., (Copyright © 2017 Académie Nationale de Pharmacie. Published by Elsevier Masson SAS. All rights reserved.)

Background: Increasing interest in patients' rights and the certainty of its impact on the quality of patient care has led to extensive research in both developed and developing countries. In 2006, the Government of Saudi Arabia publicized the Patient's Bill of Rights (PBR) that was aimed at improving patients' and health-care professionals' experience, with a focus on the quality of care provided., Objective: To determine the degree of awareness of rights among patients admitted to hospitals in Al-Madinah Al-Munawarah. The results would help policymakers understand the impact of patients' rights, and thus provide them with evidence to provide quality health-care service delivery and patient care through patients' rights., Methodology: This is an observational, analytical, cross-sectional study implemented in Al-Madinah Al-Munawarah, Saudi Arabia, using a self-administered questionnaire., Results: The study had a response rate of 83.01% and found an association between gender and knowledge for the selected items of patients' rights. However, there was no statistically significant difference between the knowledge of males and females regarding the consent form, with an awareness rate of 90% among the total sample size. However, almost half had never heard about patients' rights., Conclusion: This study shows that in Al-Madinah Al-Munawarah, Saudi Arabia, there is a low level of awareness among patients admitted to hospitals regarding their rights. Further, it was found that wall placards, mass media and health-care providers are important sources of knowledge regarding patients' rights. Health-care policymakers in Saudi Arabia should recognize the importance of patients' rights as means of providing better quality care and a higher rate of patient satisfaction by establishing measures to tackle obstacles that may impede the implementation of PBR., Competing Interests: There are no conflicts of interest

Objectives: There is great concern about the selection and quality of health college graduates and about their ability to respond to local community health needs. Community-based medical education (CBME) is a means of achieving educational relevance to community needs. In KSA, medical education has rapidly progressed in tandem with huge expansions in community health needs and expectations. This study aimed to assess the perceptions of the faculty members of the colleges of medicine and dentistry towards different concepts reflecting CBME., Methodology: This analytical, observational and cross-sectional study used a self-administered questionnaire that was given to the faculty members of the colleges of medicine and dentistry at Taibah University, KSA., Results: As many as 136 faculty members responded, a response rate of 64%. The percentage of agreement was strongest among the faculty members of the college of medicine. The study findings also showed a relationship between different concepts of CBME and faculty teaching experiences by academic positions for applying CBME. There were significant differences in the social, cultural, and ethnic aspects of medical practice., Conclusion: CBME is a means of achieving educational relevance to community needs and consequently serves as a means of implementing a community-oriented education programme.

This work describes the development, validation, and application of two simple, accurate, and reliable methods for the determination of ursodeoxycholic acid (UDCA) in bulk powder and in pharmaceutical dosage forms. The carboxylic acid group in UDCA was exploited for the development of these novel methods. Method 1 is the colorimetric determination of the drug based on its reaction with 2-nitrophenylhydrazine hydrochloride in the presence of a water-soluble carbodiimide coupler [1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide hydrochloride] and pyridine to produce an acid hydrazide derivative, which ionizes to yield an intense violet color with maximum absorption at 553 nm. Method 2 uses reversed-phase HPLC with diode-array detection for the determination of UDCA after precolumn derivatization using the same reaction mentioned above. The acid hydrazide reaction product was separated using a Pinnacle DB C8 column (4.6 × 150 mm, 5 μm particle size) and a mobile phase consisting of 0.01 M acetate buffer (pH 3)-methanol-acetonitrile (30 + 30 + 40, v/v/v) isocratically pumped at a flow rate of 1 mL/min. Ibuprofen was used as the internal standard (IS). The peaks of the reaction product and IS were monitored at 400 nm. Different experimental parameters for both methods were carefully optimized. Analytical performance of the developed methods were statistically validated for linearity, range, precision, accuracy, specificity, robustness, LOD, and LOQ. Calibration curves showed good linear relationships for concentration ranges 32-192 and 60-600 μg/mL for methods 1 and 2, respectively. The proposed methods were successfully applied for the assay of UDCA in bulk form, capsules, and oral suspension with good accuracy and precision. Assay results were statistically compared with a reference pharmacopeial HPLC method, and no significant differences were observed between proposed and reference methods.

A comprehensive stability indicating HPLC with diode array detection method was developed for the determination of the recently approved antiviral drug daclatasvir dihydrochloride (DCV) which is used for the treatment of chronic Hepatitis C Virus (HCV) genotype 3 infection. Effective chromatographic separation was achieved using Waters C8 column (4.6×250mm, 5μm particle size) with isocratic elution of the mobile phase composed of mixed phosphate buffer pH 2.5 and acetonitrile in the ratio of 75:25 (by volume). The mobile phase was pumped at a flow rate of 1.2mL/min, and quantification of DCV was based on measuring its peak areas at 306nm. DCV eluted at retention time 5.4min. Analytical performance of the proposed HPLC procedure was thoroughly validated with respect to system suitability, linearity, range, precision, accuracy, specificity, robustness, detection and quantification limits. The linearity range was 0.6-60μg/mL with correlation coefficient>0.99999. The drug was subjected to forced degradation conditions of neutral, acidic and alkaline hydrolysis, oxidation and thermal degradation. The proposed method proved to be stability-indicating by resolution of the drug from its forced-degradation products. The validated HPLC method was successfully applied to analysis of the cited drug in its tablets., (Copyright © 2017 Académie Nationale de Pharmacie. Published by Elsevier Masson SAS. All rights reserved.)

Objectives: This study aims to identify the satisfaction levels of the family members of patients in intensive care units., Methods: This is a cross-sectional analytical study. General intensive care units offer a variety of services to clinical and surgical patients. For the purpose of this study, a trained interviewer communicated with the families of patients, either before or after visiting hours., Results: The study included 208 participants: 119 (57.2%) males and 89 (42.8%) females. Seventy-three (35.1%) of the patients attended a private hospital, and 135 (64.9%) attended a public hospital in the city of Al Madinah Al- Munawarah. All of the participants were either family members or friends of patients admitted to the intensive care units at the hospitals. The responses of both groups yielded low scores on the satisfaction index. However, a relatively high score was noted in response to questions 2, 6, and 10, which concerned the care that was extended by the hospital staff to their patients, the courteous attitude of intensive care unit staff members towards patients, and patients' satisfaction with the medical care provided, respectively. A very low score was obtained for item 11, which was related to the possibility for improvements to the medical care that the patients received. Overall, greater satisfaction with the services offered by the public intensive care units was reported compared to the satisfaction with the services offered by the private intensive care units., Conclusion: An overall low score on the satisfaction index was obtained, and further studies are recommended to assess the current situation and improve the satisfaction and quality of care provided by intensive care units.

This work describes five simple and reliable spectrophotometric and chromatographic methods for analysis of the binary mixture of ketorolac tromethamine (KTR) and phenylephrine hydrochloride (PHE). Method I is based on the use of conventional Amax and derivative spectrophotometry with the zero-crossing technique where KTR was determined using its Amax and (1)D amplitudes at 323 and 341nm respectively, while PHE was determined by measuring the (1)D amplitudes at 248.5nm. Method II involves the application of the ratio spectra derivative spectrophotometry. For KTR, 12μg/mL PHE was used as a divisor and the (1)DD amplitudes at 265nm were plotted against KTR concentrations; while - by using 4μg/mL KTR as divisor - the (1)DD amplitudes at 243.5nm were found proportional to PHE concentrations. Method III depends on ratio-difference measurement where the peak to trough amplitudes between 260 and 284nm were measured and correlated to KTR concentration. Similarly, the peak to trough amplitudes between 235 and 260nm in the PHE ratio spectra were recorded. For method IV, the two compounds were separated using Merck HPTLC sheets of silica gel 60 F254 and a mobile phase composed of chloroform/methanol/ammonia (70:30:2, by volume) followed by densitometric measurement of KTR and PHE spots at 320 and 278nm respectively. Method V depends on HPLC-DAD. Effective chromatographic separation was achieved using Zorbax eclipse plus C8 column (4.6×250mm, 5μm) with a mobile phase consisting of 0.05M o-phosphoric acid and acetonitrile (50:50, by volume) at a flow rate 1mL/min and detection at 313 and 274nm for KTR and PHE respectively. Analytical performance of the developed methods was statistically validated according to the ICH guidelines with respect to linearity, ranges, precision, accuracy, detection and quantification limits. The validated spectrophotometric and chromatographic methods were successfully applied to the simultaneous analysis of KTR and PHE in synthetic mixtures of different proportions and laboratory-made ophthalmic solution., (Copyright © 2016 Académie Nationale de Pharmacie. Published by Elsevier Masson SAS. All rights reserved.)

This work presents a simple, sensitive and generic high-performance liquid chromatography with diode array detection method for the simultaneous determination of seven drugs prescribed for the treatment of erectile dysfunction and premature ejaculation. Investigated drugs include the phosphodiesterase-5 inhibitors: sildenafil, tadalafil, and vardenafil, in addition to the selective serotonin reuptake inhibitors: dapoxetine, duloxetine, fluoxetine, and paroxetine. The drugs were separated using a Waters C8 column (4.6 × 250 mm, 5 μm) with the mobile phase consisting of phosphate buffer pH 3, acetonitrile and methanol in the ratio 60:33:7. The flow rate was 1.2 mL/min, and quantification was based on measuring peak areas at 225 nm. Peaks were perfectly resolved with retention times 3.3, 3.9, 6.4, 7.5, 9.5, 10.7, and 13.4 min for vardenafil, sildenafil, paroxetine, duloxetine, dapoxetine, fluoxetine, and tadalafil, respectively. The developed method was validated with respect to system suitability, linearity, ranges, accuracy, precision, robustness, and limits of detection and quantification. The proposed method showed good linearity in the ranges 5-500, 2-200, 2-200, 3-300, 1.5-150, 2-200, and 2-200 μg/mL for sildenafil, tadalafil, vardenafil, dapoxetine, duloxetine fluoxetine, and paroxetine, respectively. The limits of detection were 0.18-0.38 μg/mL for the analyzed compounds. The applicability of the proposed method to real life situations was assessed through the analysis of commercial tablets, and satisfactory results were obtained., (© 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

This work presents the development, validation and application of four simple and direct spectrophotometric methods for determination of sodium valproate (VP) through charge transfer complexation reactions. The first method is based on the reaction of the drug with p-chloranilic acid (p-CA) in acetone to give a purple colored product with maximum absorbance at 524nm. The second method depends on the reaction of VP with dichlone (DC) in dimethylformamide forming a reddish orange product measured at 490nm. The third method is based upon the interaction of VP and picric acid (PA) in chloroform resulting in the formation of a yellow complex measured at 415nm. The fourth method involves the formation of a yellow complex peaking at 361nm upon the reaction of the drug with iodine in chloroform. Experimental conditions affecting the color development were studied and optimized. Stoichiometry of the reactions was determined. The proposed spectrophotometric procedures were effectively validated with respect to linearity, ranges, precision, accuracy, specificity, robustness, detection and quantification limits. Calibration curves of the formed color products with p-CA, DC, PA and iodine showed good linear relationships over the concentration ranges 24-144, 40-200, 2-20 and 1-8μg/mL respectively. The proposed methods were successfully applied to the assay of sodium valproate in tablets and oral solution dosage forms with good accuracy and precision. Assay results were statistically compared to a reference pharmacopoeial HPLC method where no significant differences were observed between the proposed methods and reference method., (Copyright © 2015 Elsevier B.V. All rights reserved.)

Objectives: To compare the perceptions of dental students over a 5-year period., Methods: This cohort study was carried at Taibah University, College of Dentistry, Al-Madinah Al-Munawwarah, Saudi Arabia between 2009 and 2014. Data was obtained using the Dundee Ready Education Environment Measure (DREEM), which consists of 50 items, 4 of these were irrelevant to this cohort and were excluded. All students registered in 2009 were included and followed up in 2014. Their responses were compared using the paired student's t-test., Results: Thirty-four students completed the questionnaire in 2009, and 30 of them participated in 2014 (12% drop out rate). The mean domain and total scores decreased over time. The mean scores for 6 items decreased significantly, while 4 of them had a significant increase. The lowest mean score in 2009 regarding support for stressed students increased (p=0.004) in 2014. However, the highest mean score in 2009 related to having a good social life, reduced (p=0.007) in 2014. This could be an indication of the high workload and its impact on their social lives., Conclusion: Student's perceptions were relatively low at the beginning, and remained low throughout the study. There were no significant changes in mean domain, and total scores and although scores of some items improved, most decreased over the study period.

Amlodipine besylate (AML) is available in fixed-dose combination tablets with either candesartan cilexetil (CAN) or telmisartan (TEL). This work describes a simple, selective and sensitive spectrofluorimetric method for analysis of AML/CAN and AML/TEL binary mixtures without prior separation. The method involves measurement of the native fluorescence of AML at excitation and emission wavelengths of 367 and 454 nm, respectively, in water without interference from either of the two drugs. By contrast, the intrinsic fluorescence of CAN was measured at excitation and emission wavelengths of 265 and 392 nm, respectively, in ethanol, while TEL was measured at 366 nm in 0.05 M sodium hydroxide solution using 294 nm as the excitation wavelength. The proposed spectrofluorimetric procedure was validated with respect to linearity, ranges, precision, accuracy, selectivity, robustness, detection and quantification limits. Regression analysis showed a good correlation between fluorescence intensity and concentration over the ranges 0.1-1.4, 0.025-0.25 and 0.0025-0.05 µg/mL for AML, CAN and TEL, respectively. Limits of detection were 0.034, 0.0063 and 0.0007 µg/mL for AML, CAN and TEL, respectively. The proposed method was successfully applied for the analysis of several synthetic binary mixtures of different ratios and laboratory-prepared tablets with good recoveries, and no interference from common pharmaceutical additives was observed., (Copyright © 2014 John Wiley & Sons, Ltd.)

A systematic and rigorous implementation of quality improvement processes is likely to improve the well-being of staff members and heighten their job satisfaction. Assessing professionals' perceptions of health care quality should lead to the betterment of health care services. In Saudi Arabia, no previous studies examine how university health professionals view health care quality concepts. A cross-sectional analytical study employing a self-administered questionnaire with 43 statements assessing quality perceptions of academic health care professionals was used. Despite the agreement of health professionals on numerous quality concepts addressed in this study, there was insufficient agreement on 10 core quality concepts, 3 of which were the following: "quality focuses on customers" (50%), "quality is tangible and therefore measurable" (29.3%), and "quality is data-driven" (62%). Hence, providing health professionals with relevant training likely will generate a better understanding of quality concepts and optimize their performance.

Unlabelled: The use of prophylactic antibiotics for the prevention of infective endocarditis following dental procedures has long been debated and there is still confusion regarding its efficacy. As a result, the prophylactic treatment varies considerably amongst different countries across the world and amongst different dental practitioners., Aim: To evaluate the knowledge of dental staff regarding the guidelines for the prevention of infective endocarditis., Methods: This was a cross sectional analytical study which included all staff members. A self administered questionnaire was used and responses were "graded" according to the American Heart Association (AHA) guidelines., Results: The response rate was 87% (N=39) and 97% reported to use the AHA guidelines; 66% reported their knowledge was based on previous training and scientific journals. Of those cardiac conditions and dental procedures which required prophylaxis; 47% and 65% chose the correct option, respectively. Penicillin was prescribed as the drug of choice by the majority of respondents., Conclusions: Although almost all staff reported the use of the AHA guidelines, many were not following them. The study emphasizes the need for continuous education and evaluation of this critical aspect of dentistry.

A new simple spectrophotometric method was developed for the determination of binary mixtures without prior separation. The method is based on the generation of ratio spectra of compound X by using a standard spectrum of compound Y as a divisor. The peak to trough amplitudes between two selected wavelengths in the ratio spectra are proportional to concentration of X without interference from Y . The method was demonstrated by determination of two drug combinations. The first consists of the two antihyperlipidemics: atorvastatin calcium (ATV) and ezetimibe (EZE), and the second comprises the antihypertensives: candesartan cilexetil (CAN) and hydrochlorothiazide (HCT). For mixture 1, ATV was determined using 10 μg/mL EZE as the divisor to generate the ratio spectra, and the peak to trough amplitudes between 231 and 276 nm were plotted against ATV concentration. Similarly, by using 10 μg/mL ATV as divisor, the peak to trough amplitudes between 231 and 276 nm were found proportional to EZE concentration. Calibration curves were linear in the range 2.5-40 μg/mL for both drugs. For mixture 2, divisor concentration was 7.5 μg/mL for both drugs. CAN was determined using its peak to trough amplitudes at 251 and 277 nm, while HCT was estimated using the amplitudes between 251 and 276 nm. The measured amplitudes were linearly correlated to concentration in the ranges 2.5-50 and 1-30 μg/mL for CAN and HCT, respectively. The proposed spectrophotometric method was validated and successfully applied for the assay of both drug combinations in several laboratory-prepared mixtures and commercial tablets.

Introduction: Caries is associated with high counts of mutans streptococci (MS), lactobacillus (LB), and a low saliva buffering capacity (BC). No study using odds ratios (OR) has correlated caries and these factors and no similar study has been done in Saudi Arabia before., Objectives: To determine: The prevalence of caries, the number of colony forming units (CFUs) of MS and LB, the saliva buffering capacity (BC) and the relationship between these factors., Materials and Methods: This was an analytical cross sectional study on children from Madinah. Caries was recorded using dmft/DMFT (decayed, missing, filled teeth). The scores for MS and LB and the BC of saliva was calculated using the Caries Risk Test (CRT)(®)., Results: A total of 316 students were examined; two-thirds (62%) were female and 25% were caries free. Saliva was collected from 235 participants and the majority had high MS and LB scores (66 and 71%, respectively) while 25% had a low saliva BC. The odds for those who had high LB and MS CFUs, were 9 and 4 times more at risk to developing dental caries and those with a low BC had significantly more caries (P = 0.03). The likelihood for those having severe caries and high counts of LB and MS was 25 (P < 0.01) and 6 (P = 0.042) times greater, respectively, compared to those with no or mild caries. Those with multiple risk factors were more likely to have caries compared to those with single or no risk factors present., Conclusions: The prevalence of caries was relatively high and many respondents had greater than 10(5) CFUs/ml of MS and LB. Almost all with a low BC had severe caries. There was a strong correlation between high MS, high LB, and low BC and the high prevalence of caries; hence the combination of these factors could be confidently used to predict caries in this population.

A rapid, simple, and accurate first-derivative spectrophotometric method has been established for the determination of either cephalexin or cephradine in urine. Quantitative analysis of each antibiotic was achieved by measuring the peak amplitude at 268 nm. The relative and absolute recoveries ranged from 98.90 to 104.00% for cephalexin and from 97.85 to 105.10% for cephradine. The within-day coefficient of variation varied from 3.27 to 6.45%. The applicability of the method for the determination of the cumulative amount of either cephalexin or cephradine excreted unchanged in urine, following an oral dose containing 500 mg of the drug to a human male volunteer, is demonstrated.

A simple, sensitive and accurate colorimetric method is described for the quantitative determination of pindolol either in the pure form or in its tablets. The method is based on the oxidation of the indole moiety in pindolol with potassium persulphate or hydrogen peroxide-in acid medium-to give a highly coloured product that exhibits maximum absorption at 535 nm and 570 nm, respectively. Beer's law is obeyed over concentrations ranging from 0.07-0.35 mg/10 ml for potassium persulphate and 0.1-0.5 mg/10 ml for hydrogen peroxide with mean recoveries of 99.6+/-0.6 and 99.8+/-0.9%, respectively. The method is applied for the assay of pindolol tablets without any interference due to tablet fillers.

This paper describes a spectrophotometric method for the assay of phenothiazines (and also opipramol, which is similar but contains a CC linkage instead of the S atom of the phenothiazines) as the pure drug or in tablets or solutions for injection. The colour is produced by heating a solution of the drug or drug preparation with a solution of chloramine-T. The coloured product can be extracted into chloroform before the colour measurement or the whole process carried out in ethanol solution, the colour of which is then measured.

Chlorpromazine hydrochloride, promethazine hydrochloride, promazine hydrochloride, perphenazine, thioridazine hydrochloride, chlorprothexine, opipramol hydrochloride, amitriptyline hydrochloride, imipramine hydrochloride and hydroxyzine hydrochloride are estimated in their pure state and in pharmaceutical formulations by means of the reaction of the free bases with chloranil in dioxan-ethanol medium to give a coloured product with maximal absorbance at 550 nm. The method is precise, accurate and specific and recommended for routine analysis for the drugs mentioned.

The colorimetric determination of mefenamic acid and flufenamic acid with potassium ferricyanide in sodium hydroxide medium is described. The orange product is measured at 464 nm. The molar absorptivities are 1.9 x 10(3) and 2.9 x 10(3) 1.mole(-1).cm(-1) for mefenamic acid and flufenamic acid, respectively. The method has been applied successfully to the determination of these drugs in capsules.

A spectrophotometric method for the determination of some tetracyclines as well as some cephalosporins is described. The drug is boiled with ammonium vanadate solution in sulphuric acid medium for 10 min and the absorbance of the colour developed is measured at 750 nm. The proposed method can be successfully applied to the determination of tetracycline hydrochloride, oxytetracycline hydrochloride, doxycycline hyclate, demeclocycline hydrochloride, chlortetracycline hydrochloride, cephalothin sodium, cephaloridine and cephapirin sodium. These drugs can be determined either in pure form or in pharmaceutical preparations.

First and second derivative ultraviolet spectrometric methods are described for the estimation of indomethacin, naproxen, and ibuprofen in pharmaceutical dosage forms. The proposed methods permit the rapid, precise, and accurate determination of indomethacin capsules BP, naproxen capsules, and ibuprofen tablets BP. Matrix interference is successfully corrected. The results obtained by first and second derivative techniques are in accord with those obtained by the official assay method.

A spectrophotometric method for determining some phenothiazines, some tetracyclines and chloramphenicol is described. Chlorpromazine hydrochloride, promazine hydrochloride, promethazine hydrochloride, perphenazine and fluphenazine hydrochloride are reacted with sodium cobaltinitrite in phosphoric acid. The red colour developed is measured at 530, 513, 515, 530 and 500 nm, respectively. Tetracycline hydrochloride, oxytetracycline hydrochloride, chlortetracycline hydrochloride, doxycycline hyclate and demeclocycline hydrochloride are reacted with the reagent in aqueous acetic acid. The yellow colour produced is measured at 256, 294, 262, 243 and 246 nm, respectively. Chloramphenicol is determined similarly to the tetracyclines after hydrolysis with 40% sodium hydroxide solution and the colour is measured at 240 nm. The proposed method has been successfully applied to the determination of these drugs in various pharmaceutical preparations.

A simple and sensitive spectrophotometric method for the assay of codeine, emetine and pilocarpine is described, based on the interaction of these drugs (as n-electron donors) with 2,3-dichloro-5,6-dicyano-p-benzoquinone (as pi -acceptor) to give a highly coloured radical anion which exhibits maximum absorption at 460 nm. Formation of the radical anion has been established by electron spin resonance measurements. Beer's law is obeyed for the alkaloids investigated. The assay results are in accord with pharmacopoeial assay results. The procedure is sufficiently sensitive to permit unit dose assay of the individual alkaloids in pharmaceutical formulations.

A colorimetric method for the determination of five cephalosporins (cefoxitin sodium, cefotaxime sodium, cephapirin sodium, cephalothin sodium and cephaloridine), based on the blue colour formed by reaction of the cephalosporins with ammonium molybdate, is described. The effects of reagent concentration and reaction conditions are discussed. The proposed method has been applied to the analysis of cephalosporin injections, the results of which are in good agreement with those obtained by the official method of the British Pharmacopoeia.

Six phenothiazine drugs (chlorpromazine hydrochloride, promethazine hydrochloride, promazine hydrochloride, perphenazine, acetophenazine maleate and trifluoperazine hydrochloride) have been determined by titration with potassium ferricyanide in phosphoric acid medium with Methylene Blue as a screening indicator. The results were in agreement with those obtained by the official methods.

A titrimetric method for the evaluation of some tranquillizers and antidepressants is proposed. The method is based on the oxidation of these drugs by iodine monochloride, in strong acid medium, the iodine liberated being titrated with potassium iodate by the Andrews method. The proposed method is applied successfully for the determination of 9 phenothiazines, 1 thioxanthene, 2 acid hydrazides and 1 dibenzazepine containing a double bond (Opipramol). Tablets, solutions for injection, and drops are also determined by the proposed method. The mechanism of oxidation for each species is suggested and the results obtained agree with these suggestions. Some official and non-official methods for the evaluation of the drugs have been compared with the iodine monochloride method, which is found to be superior in specificity, sensitivity and speed.

Some basic cardiovascular drugs containing secondary or tertiary amino groups are determined spectrophotometrically. The method is simple and sensitive; it is based on the interaction of the drugs, as n-electron donors, with 2,3-dichloro-5,6-dicyano-p-benzoquinone (DDQ) as a pi-acceptor. The highly coloured radical anion exhibits maximum absorption at 460 nm. The drugs determined are pindolol, dipyridamole, hydralazine hydrochloride, quinidine sulphate, prenylamine lactate and tolazoline hydrochloride. Beer's law is obeyed for these drugs. The procedure is sensitive enough to permit unit dose assay of the individual drugs in their pharmaceutical formulations. The assay results are in accord with the pharmacopoeial assay results.

A simple and sensitive colorimetric method for the assay of quinine sulphate, primaquine diphosphate, amodiaquine hydrochloride and pyrimethamine is described. The method is based on the interaction of the drugs and p-chloranilic acid to give a stable product with an intense colour which can be used for the determination of these antimalarials in their pharmaceutical preparations.