Objective—To determine whether 1% diclofenac
liposomal suspension (DLS) ointment would be
absorbed transdermally and attenuate experimentally
induced subcutaneous inflammation in horses.
Animals—7 healthy adult horses
Procedure—Inflammation was produced by injecting
1% sterile carrageenan into subcutaneously implanted
tissue cages 8 hours before (time –8) and at the
time of application of test ointment. A crossover
design was used. Horses received 1 of 2 treatments
(topically administered control or DLS ointments) during
48 hours of carrageenan-induced subcutaneous
inflammation. A single application of test ointment
(7.2 g) was applied over each tissue cage (time 0).
Samples of transudate and blood were collected at
–8, 0, 6, 12, 18, 24, 30, 36, and 48 hours. Plasma and
transudate diclofenac concentrations were determined
by use of high-performance liquid chromatography.
Transudate concentrations of prostaglandin E2
(PGE2) were determined with a competitive enzyme
Results—DLS was absorbed transdermally. The highest
concentration (mean ± SEM, 76.2 ± 29 ng/mL)
was detectable in tissue-cage fluid within 18 hours
after application. Minimal concentrations of diclofenac
were detectable in plasma. Application of DLS significantly
decreased transudate concentrations of PGE2
at 6 and 30 hours. Decreases in PGE2 concentration
were observed in the DLS group at all collection
Conclusions and Clinical Relevance—A single topical
application of DLS resulted in concentrations of
diclofenac in transudate within 6 hours and significantly
attenuated carrageenan-induced local production
of PGE2. Results of this study suggest that DLS
is readily absorbed transdermally and may be efficacious
for reducing subcutaneous inflammation in
horses. ( Am J Vet Res 2004;65:271–276)
Objective—To evaluate effects of protamine zinc
insulin (PZI) on control of glycemia in cats with newly
diagnosed diabetes mellitus or poorly controlled diabetes.
Animals—67 diabetic cats.
Procedure—34 cats with newly diagnosed diabetes
and 33 cats with poorly controlled diabetes were
treated with PZI twice daily for 45 days. Control of
glycemia was assessed on days 7, 14, 30, and 45 by
evaluation of clinical response, change in body
weight, serum fructosamine concentration, blood glucose
concentration measured 1, 3, 5, 7, and 9 hours
after administration of PZI, lowest blood glucose concentration,
and mean blood glucose concentration
during the 9-hour period after administration.
Adjustments in dosage of PZI were made as needed
to attain control of glycemia.
Results—For all cats, a significant increase in mean
dosage of PZI and significant decreases in 9-hour mean
blood glucose concentration, lowest mean blood glucose
concentration, and mean serum fructosamine
concentration were detected. For cats with poorly controlled
diabetes, 9-hour mean blood glucose concentration
and mean serum fructosamine concentration
were significantly decreased on day 45, compared with
day 0. Ninety percent of owners reported improvement
or resolution of clinical signs by day 45.
Conclusions and Clinical Relevance—Results suggest
that PZI was effective for control of glycemia in
cats with newly diagnosed or poorly controlled diabetes
and may be used as an initial treatment or as an
alternative treatment in cats that do not respond to
treatment with other types of insulin. ( J Am Vet Med
Objective—To evaluate and compare characteristics of a commercially manufactured protamine zinc insulin (PZI) product and PZI products obtained from various compounding pharmacies.
Sample—112 vials of PZI (16 vials of the commercially manufactured product and 8 vials from each of 12 compounding pharmacies) purchased over an 8-month period.
Procedures—Validated methods were used to analyze 2 vials of each product at 4 time points. Appearance, endotoxin concentration, crystal size, insulin concentration in the supernatant, pH, total insulin and zinc concentrations, and species of insulin origin were evaluated.
Results—All 16 vials of commercially manufactured PZI met United States Pharmacopeia (USP) specifications. Of 96 vials of compounded PZI, 1 (1 %) contained a concentration of endotoxin > 32 endotoxin U/mL, 23 (24%) had concentrations of insulin in the supernatant > 1.0 U/mL, and 45 (47%) had pH values < 7.1 or > 7.4; all of these values were outside of specifications. Several vials of compounded PZI (52/96 [54%]) did not meet specifications for zinc concentration (0.06 to 0.1 mg/mL for 40 U of insulin/mL, 0.075 to 0.12 mg/mL for 50 U of insulin/mL, and 0.15 to 0.25 mg/mL for 100 U of insulin/mL), and total insulin concentration in 36 [38%] vials was < 90% of the labeled concentration.
Conclusions and Clinical Relevance—Only 1 of 12 compounded PZI products met all USP specifications in all vials tested. Use of compounded PZI insulin products could potentially lead to serious problems with glycemic control in veterinary patients.