Physician and Patient Preferences for Sustained Release Antihypertensive Preparations in the Kumasi Metropolis; Ghana

Background: Non-adherence to therapy is a major reason for the low control rate of hypertension in Ghana today. Sustained release (SR) antihypertensive preparations are useful in promoting adherence to therapy because of the reduced daily dosing frequency; stable drug levels and reduced toxicity which enhances compliance. One major concern about SR antihypertensives is whether they can be substituted with one another to produce the same effect. Objectives: This study sought to determine the preferences of physicians and patients for various SR antihypertensive medications in the Kumasi metropolis of Ghana. The views of the respondents on whether the brands of the most used SR antihypertensive were therapeutically equivalent and interchangeable were ascertained. Methods: Seventy-three (73) community pharmacies; 66 doctors and 150 patients in 50 public; private and mission hospitals and clinics within the Kumasi metropolis were purposively sampled. Respondents were interviewed via interviewer administered structured questionnaires and the information gathered was coded; entered into SPSS software version (16) and analysed. The results were presented as frequencies and proportions; and in tables as well as in figures.Results: SR nifedipine was the most stocked and used SR antihypertensive drug while Nifecard XL (30 mg) was the preferred brand of patients and doctors. Clinicians considered effectiveness and compliance as two major reasons for their preference for SR nifedipine while patients considered affordability and availability. Sixty percent of prescribers and 41% of patients were of the opinion that all brands of SR nifedipine were interchangeable. Conclusion: There is a gap between prescribers and patients about SR nifedipine brands interchangeability which needs to be bridged to optimize their use to attain better treatment outcomes in Ghana. There is need for continuous education on concepts of therapeutic equivalence and generics substitution for all stakeholders to address the problem of non-adherence to hypertension therapy in Ghana

Estimation of the release profiles of multi-unit dose tablets of theophylline from the release profiles of their components

Purpose: The objective of this study is to investigate whether the drug release profile of a multi-unit dose form consisting of fast and slow release components can be predicted from the release profiles of their components by simple summation. Method: The fast release component consisted of conventional granules of theophylline made by wet massing the drug powder with starch mucilage (20w/v). The slow release component consisted of matrix granules of the drug made by triturating the drug powder with melted carnuba wax (i.e. melt granulation). Each type of granules was compressed to tablets of weight 100; 150 or 200mg. To form the multi-unit dosage tablets of drug content 300mg each; the conventional and matrix granules were mixed in the ratio 1:2; 1:1 and 2:1; and compressed. The tablets were subjected to dissolution test and from the experimental release curve the prompt release (mp) in the first 1h; the maximum release (m ) and the time to attain it (t ) were obtained. Result: For a given composition of the multi-unit dose tablets; the theoretical release curve was obtained by summation of the release from each component at the different time intervals. The mp values of the theoretically estimated release curves were generally higher; while their t values were generally shorter than the corresponding values for the experimental curves. Conclusion: The indication is that drug release from the multi-unit dose tablets was more retarded than could be theoretically estimated. Apparently; the two components interfere with each other's release