การประเมินคุณค่ายาเตรียมขี้ผึ้งตำรับต่างๆ ของคลินตามัยซิน / สมฤทัย จิตภักดีบดินทร์ =Evalution of various ointment preparations of clindamycin / Somrutai Jitpukdeebodindra
The feasibility of making a new preparation of any drug must be first evaluated. The evaluation of ointment preparation consists of penetration test, the study of drug release from its base, experiment on possible dermatological irritation and stability test. If the penetration and drug release rates of any preparations are low and their dosage forms unstable, they are unvaluable for therapeutic use. In addition, preparation which are therapeutic but caused irritation to the skin are unsuitable as well. Clindamycin is a useful antibiotic for dermatological treatment. Ointment preparation were investigated by this research. Clindamycin release rates were studied by diffusion techniques according to method developed by Botarri et al. The stability of preparation was studied by bactericidal test, together with a 5-Freeze-Thaw cycle technique. Physical changes observed are : consistency or stiffeness, color, odor, sedimentation, etc. The bactericidal property of the preparation was studied with anaerobic bacteria (Propionibacterium acnes) : gram positive aerobic bacteria (Staphylococcus aureus) and gram negative aerobic bacteria (Peudomonas aeruginosa) by measuring the inhibition zones. Fifty volunteers were studied ointment penetrating characteristic by using a very early technique of Wild. Lastly modification of prophetic skin test with two hundred volunteers were carried out to study the preparation’s irritation possibility. The experiment revealed that water soluble ointment had the maximum clindamycin release rate, about 12.06% ± 0.10% per 180 minutes. But clindamycin in emulsion cintment base penetrated into the skin most, about 44.94% ±0.09% and inhibited the three bacteria most effectively. Gram positive aerobic bacteria such as Staphylococcus aureus was more sensitive to clindamycin, either before and after a 5 Freeze-Thaw cycles, than Propionibacterium acnes and Pseudomonas aeruginosa which were anaerobic bacteria and gram negative aerobic bacteria respectively. All ointment preparations did not irritate the skin and had physical and microbiological stability with 99% confidence.