V. Bruce Sunderland

Enhanced pharmacy services, barriers and facilitators in Australia's community pharmacies: Australia's National Pharmacy Database Project.

Objective To report the frequency of 27 enhanced pharmacy services (EPS) provided in Australias community pharmacies and to analyse barriers and facilitators for providing priority services. Setting A large representative sample of community pharmacies in Australia in 2002.

Pharmacokinetics of Nasal Fentanyl

Objective: To investigate the pharmacokinetics of intranasal fentanyl in adult post‐operative female patients.

Kinetics of the degradation of methyl, ethyl and n-propyl 4-hydroxybenzoate esters in aqueous solution

Abstract The kinetics of the hydrolysis of methyl, ethyl and n-propyl 4-hydroxybenzoate esters and a subsequent decarboxylation of 4-hydroxybenzoic acid have been studied at pH 1.26–10.59 and the sterilizing temperature of 130.5°C. Enthalpies (ΔH∗) and entropies (ΔS∗) of activation are reported for kobs and the derived rate constants. The decarboxylation reaction showed a maximum rate near the mid-pH region where the esters were more susceptible to hydrolysis. The overall pathway for the degradation of the esters was accounted for by a consecutive reaction sequence: where A represents ester, B, 4-hydroxybenzoic acid and C, phenol. Interference with the spectrophotometric assay by the subsequent oxidation of phenol, made necessary the exhaustive de-oxygenation of solutions for the kinetic runs where phenol was formed. The esters were found to be sufficiently stable to withstand a heat sterilization process within the pH range 3–6. The rate of phenol formation by decarboxylation of the acid was greater in the pH range where the esters are frequently used commercially, as preservatives.

Solubilities and intrinsic dissolution rates of sulphamethoxazole and trimethoprim

The influence of pH on the dissolution rates and solubilities of sulphamethoxazole and trimethoprim have been examined. Sulphamethoxazole was evaluated in buffers of ionic strength 0.5 mol dm−3 over the pH range 0.45–7.8 and at 25, 32 and 37 °C. The minimum solubility of sulphamethoxazole was 28.1 mg/100 mL at pH 3.22 and 25 °C. Solubilities increased significantly with both increased and decreased pH. Intrinsic dissolution rates demonstrated a linear relationship with the solubility data. Trimethoprim solubility was both buffer‐ and pH‐dependent. In both water and hydrochloric acid solution at 32 °C the solubility of trimethoprim increased from 50 mg/100 mL in water at pH 8.54 to a maximum of 1550 mg/100 mL at pH 5.5. This maximum solubility was in excess of that predicted theoretically and may be due to supersaturation. Below pH 2 the solubility of protonated trimethoprim diminished from 1125 mg/100 mL with decreasing pH. This was due to the common ion effect. Intrinsic dissolution rates increased as pH was decreased with hydrochloric acid from 6.00 to 1.78, but decreased at pH 1.48 due to the common ion effect. Dissolution profiles of trimethoprim showed complex patterns dependent upon pH. The profile was zero‐order at pH 6.00 and became distinctly stepwise at pH 5.5, this effect becoming less pronounced at lower pH values. This was reconciled in terms of the rate of formation of trimethoprim hydrochloride on the surface of the disc and the differing dissolution rates of this species and trimethoprim. A simple relationship between solubility and dissolution rate was not observed.

A systematic review of the literature comparing the practices of dispensing and non-dispensing doctors.

OBJECTIVES Some doctors perform the dual roles of prescribing and dispensing pharmaceuticals. The dispensing doctors (DDs) role may give rise to prescribing behaviours that vary from those of non-DDs. The aim of this review was to systematically and comparatively appraise the research evidence related to the practices of DDs. METHODS A systematic search of bibliographic databases and reference lists from selected papers were the sources of the data. Inclusion criteria were papers published in English, between 1970 and 2008 that provided quantitative data comparing the practices of DDs and non-DDs. At least two of the authors abstracted data from all eligible papers using a purpose-made data extraction form. RESULTS Twenty-one papers were included in this review. Evidence indicated that DDs prescribed more pharmaceutical items and less often generically than non-DDs. There was limited evidence to suggest that DDs prescribed less judiciously and were associated with poor dispensing standards. Patient convenience and access to pharmaceuticals were main reasons for doctors to dispense. CONCLUSION DDs can fill an important gap in the provision of pharmaceuticals for their patients especially where health workforce shortages exist. There was evidence the dispensing role influenced prescribing. Patient convenience should be balanced against scarce medical resources, being utilised for dispensing.

A comparative evaluation of pharmacy services in single and no pharmacy towns

BackgroundRecent attention has focused on access of communities to pharmacy services in rural areas. To increase access to pharmacy services in rural Western Australia some doctors have been granted a licence to dispense medication on the rationale that a pharmacy would not be economically viable in that community. However, there have been no studies conducted on whether a doctor dispensing service adequately provides a pharmacy service with respect to access and quality.MethodResidents of seven single pharmacy towns and seven non-pharmacy rural towns were surveyed to evaluate pharmacy services delivered by a pharmacist and doctor. The towns were chosen to match closely on key demographic features, with an average population of 1,246 and 1,263 respectively. A random sample of 150 households from each town was sent the questionnaire on pharmacy services (1050 in each group). Data was also collected from the Health Insurance Commission (HIC) on dispensing locations for the residents of the two groups of towns.ResultsThere was a significant difference in access to pharmacy services with 82.4% of participants from pharmacy towns accessing medications within their town compared to 51.3% of non-pharmacy town participants. The HIC data supported these trends with pharmacy town residents having relatively higher prescription rates within their town compared to non-pharmacy town residents where they were more likely to access prescriptions out of their town.ConclusionPharmacy town participants were more satisfied with access to health and pharmacy services within their town. Continuation of the doctor dispensing policy requires a greater consideration of the pharmacy needs of rural residents.

In Vitro and In Vivo Release of Naltrexone from Biodegradable Depot Systems

ABSTRACT The aim of this study was to prepare poly(d, l-lactide) (PLA) microspheres containing naltrexone (NTX) by a solvent evaporation method, and to evaluate both in vitro and in vivo release characteristics and histopathological findings of tissue surrounding an implant formulation in rats. This method enabled the preparation of microspheres of regular shape and relatively narrow particle size distribution. The in vitro release profiles of NTX from PLA microspheres showed the release of NTX did not follow zero-order kinetics. An initial burst release was observed, subsequently followed by a nearly constant rate of 0.4% per day after ten days. The cumulative amount of NTX released at the end of 60 days was 80%. Compressed microspheres showed near zero-order sustained release of NTX for 360 days. The plasma NTX levels in rats showed that for compressed microspheres NTX concentrations were constant and exceeded 2 ng/mL for 28 days. Throughout the 28 days of study, the implantations cause a minor inflammatory response, which can be regarded as a normal defence mechanism. The sustained release performance of NTX from the biodegradable depot systems may provide a reliable, convenient, and safe mechanism for the administration of NTX for the long-term treatment of opioid dependence.

No‐Blame Medication Administration Error Reporting by Nursing Staff at a Teaching Hospital in Australia

The medication administration error rate on a surgical ward in an Australian teaching hospital was determined using a “no‐blame” self‐reporting method. The self‐reported error rate using the existing ward stock (WS) drug distribution system was determined over a 23‐day period. After the ward underwent a number of interventions designed using failure mode and effects analysis (FMEA), a method of systems analysis employed to assess a process and identify problem areas that might lead to errors, the “no‐blame” self‐reported error rate was again assessed, over a 31‐day period. The no‐blame aspect of the study was emphasised during all education sessions prior to the study commencing. All reports, made on a simple form designed specifically for the study, were reviewed and collated by a pharmacist in a non‐punitive manner. During the WS phase of the study, 182 errors were reported, compared with 170 in the FMEA phase. The error rate was 3.3 per cent of doses administered for the WS system and 2.3 per cent for the FMEA system. The difference between the two phases was found to be significant (P<0.001). These results show an error rate less than that previously found using a direct observation technique. However, used in conjunction with the disguised‐observer technique, the no‐blame self‐reporting method may be a useful part of a continuous error detection process in hospitals.

Alkaline hydrolysis of methyl, ethyl and n-propyl 4-hydroxybenzoate esters in the liquid and frozen states

Abstract The alkaline hydrolysis of the methyl, ethyl and n-propyl esters of 4-hydroxybenzoic acid was studied in the liquid and frozen states in sodium hydroxide solutions. The temperature range was −26 to 60°C. Significant acceleration of the reaction rate was evident in the frozen state compared with rates found at liquid state temperatures. The maximum reaction rate in the frozen state occurred in the temperature range −12 to −10°C. Methyl 4-hydroxybenzoate showed more than a 20-fold increased rate constant from 7.17 × 10−6 s−1 at 30°C to 1.53 × 10−4 s−1 at −9°C in a 1.00 × 10−2 M solution of sodium hydroxide. Rate constants in the liquid and frozen states followed pseudo first-order kinetics over 2–4 half-lives of reaction. Data were fitted to a theoretical model describing the reaction rate in the frozen state as dependent upon the increased concentration of solutes in liquid vesicles in the frozen state and the predicted reduction in the reaction rate constant with temperature decrease. Although the data exhibited similar trends to that predicted by the model, there was frequently a 50% difference in the rates observed compared with those predicted. This study has clearly demonstrated that there is a significantly increased rate of hydrolysis of these esters in the frozen state. This is a further indication that it cannot be assumed that drugs stored in solution will necessarily be stabilized, or their stability enhanced, on freezing. Storage under refrigeration conditions (4–8°C) results in enhanced shelf-lives compared with deep-freeze storage at −20°C under the conditions of this study.

Alkaline ethanolysis of methyl 4-hydroxybenzoate and hydrolysis of methyl and ethyl 4-hydroxybenzoates in ethanol—water systems

Abstract Kinetics of the simultaneous hydrolysis and ethanolysis of methyl 4-hydroxybenzoate were studied in 0.5 mol dm −3 alkali in ethanol-water mixtures. Rates of hydrolysis of the ethyl ester, an intermediate product, were also evaluated in these solvent systems. Kinetics of the ethanolysis of the methyl ester were further studied in ethanol in the presence and absence of 0.5 mol dm −3 alkali. Rates of the aqueous hydrolysis reactions of both esters were also studied in 0.5 mol dm −3 alkali. Approximately a 100-fold reduction in the rate of hydrolysis of the methyl ester in 82.43% w/w ethanol occurred compared with water. The majority of this effect was over the solvent range from water to 50% w/w ethanol. Rate changes with solvent composition for ethanolysis of methyl ester were dominated by changes in the ΔH ∗ values. Larger changes in ΔH ∗ and ΔS ∗ values were exhibited for the hydrolysis reactions. These values were, however, compensatory on the reaction rate, a maximum in this compensation occurring at ≅ 10% w/w of ethanol. Hence addition of ethanol to an alkaline aqueous solution of methyl 4-hydroxybenzoate resulted in a markedly reduced rate of hydrolysis, and formation of the ethyl ester over the temperature range 25.0–46.1°C studied. This ester subsequently underwent a slower hydrolysis reaction when compared with the methyl ester.