Abstract
For the topical treatment of postherpetic neuralgia, 8 kinds of lotions and ointments containing aspirin, anesthesin glycerin and salicylic acid, respectively, were prepared.The values of consistency and spreadability of 2% aspirin ointment preparation measured with a penetrometer and spreadmeter, respectively, were constant for 21 days when reserved at 20°C or 30°C.
Aspirin in the ointment was stable under those conditions. Among the preparations applied to the patients 2% aspirin ointment (yield value, 7000 dyn/ cm2) was suitable for topical application and most effective in respect to the pain relief. The pain started to fade within 3-5 minutes and the pain relief usually lasted for 5-7 hours.Salicylic acid ointment also afforded an analgesic effect, although the duration of the efficacy was shorter than that of the aspirin ointment.
The oral administration of aspirin and topical application of the aspirin ointment to the patients with postherpetic neuralgia showed the similar analgesic effect on arthrodynia derived from chronic articular rheumatism.From these results, the site of action of aspirin seemed to be the peripheral sensory nerve endings.
